heart disease deaths

Are Omega-3 Supplements Safe?

by

The Flaws And Blind Spots In This Study

Author: Dr. Stephen Chaney

Pendulum
Pendulum

Has the omega-3 pendulum swung again? The recent headlines are downright scary. For example:

  • “Fish Oil May Increase the Risk of Stroke and Heart Conditions.”
  • “Fish Oil Supplements May Cause Harm, Study Finds. Is It Time to Ditch Them?”
  • “Fish Oil Supplements May Lead to Heart Problems”.
  • “Regular Use of Fish Oil Supplements Might Increase, Rather Than Lessen, The Risk of First Time Heart Disease and Stroke Among Those in Good Cardiovascular Health.”

Yikes! That sounds bad. Should we be thinking about giving up our omega-3 supplements?

But wait. Just a few weeks earlier we were reading headlines about the benefits and lack of side effects from omega-3 supplements. That’s confusing. Which headlines are correct?

To answer these questions:

  • I will point out the flaws and blind spots in the study.
  • I will strip away the hyperbole and put the headlines into perspective.

How Was The Study Done?

clinical studyThe investigators made use of data from the UK Biobank Study. The UK Biobank Study is a large, long-term study in the United Kingdom which was designed to investigate the contributions of genetic predisposition and environmental exposure [including diet and supplementation] to the development of disease.

The UK Biobank Study enrolled 502,461 participants, aged 40-69 years, between January 1st, 2006 and December 31st, 2010. Participants were followed from entry into the program until March 31st 2021, an average of 11.9 years.

The current study excluded any participants who had a diagnosis of atrial fibrillation, heart failure, heart attack, stroke, or cancer at entry into the study, leaving 415,737 participants.

The participants were:

  • 55% women.
  • Average age of 56 years, with 83.4% of them below 65 years old at entry into the study.
  • 94.5% white.

The study was designed in a unique manner, in that it was designed to test the effect of omega-3 supplements on 6 specific transitions:

  • Primary prevention. This measured the transition of healthy (no diagnosed heart disease) people to either atrial fibrillation, major cardiovascular events, or death.
  • Secondary prevention. This measured the transition from atrial fibrillation to either major cardiovascular events or death.
  • Tertiary prevention. This measured the transition from major cardiovascular events to death.
  • Major cardiovascular events were further broken down to heart attacks, stroke and heart failure.

Participants were asked whether they used fish oil supplements when they entered the study and were categorized as either regular users or non-users. [Note: The users were not asked the dose or brand of fish oil supplements they used.]

Deaths were obtained from the national death registry and disease diagnosis from the National Health Service.

Are Omega-3 Supplements Safe?

omega-3 fish oil supplementHere is what the study found.

Primary Prevention – For healthy individuals (defined as having no diagnosed heart disease) using omega-3 supplements for an average of 11.9 years:

  • Increased the risk of atrial fibrillation by 13%.
  • Did not affect the risk of major cardiovascular events and death were unaffected by omega-3 supplementation.
  • When major cardiovascular events were broken down to their component parts, omega-3 supplementation:
    • Decreased the risk of heart failure by 8%.
    • Increased the risk of stroke by 5% (this was just barely statistically significance).
    • Did not affect the risk of heart attack.

Secondary Prevention – For individuals with atrial fibrillation omega-3 supplementation:

  • Decreased the risk of major cardiovascular events by 9%.
  • Decreased the risk of death by 8%.
  • When major cardiovascular events were broken down into their component parts, omega-3 supplementation:
  • Decreased the risk of heart attacks by 15%.
  • Had no effect on the risk of stroke or heart failure.

Tertiary Prevention – For people who suffered major cardiovascular events during the study omega-3 thumbs upsupplementation:

  • Decreased the risk of death by 8%.

Since this is a very complex set of data, I have coded positive results in green and negative results in red.

And as if these complexities were not enough, when the investigators broke these effects down by population groups:

  • Omega-3 supplementation decreased the transition from healthy to death for men (7% decrease) and participants older than 65 (9% decrease).

I will discuss the significance of these observations below.

The authors concluded, “Regular use of fish oil supplements might be a risk factor for atrial fibrillation and stroke among the general population but could be beneficial for [reducing] progression of cardiovascular disease from atrial fibrillation to major adverse cardiovascular events, and from atrial fibrillation to death.”

In short, they were suggesting that omega-3 supplements should be avoided by the general population because they have no positive benefits and might increase the risk of atrial fibrillation and stroke. But omega-3 supplements may be useful for those who already have heart disease.

Some of the articles you may have read about the study repeated this message. Others just emphasized the negative aspects of the study.

But is this message accurate? Let me start by discussing the flaws, blind spots, and hidden data in this study. Then I will summarize the 3 key findings of the study and tell you what they mean for you.

The Flaws, Blind Spots, And Hidden Data In This Study

flawsFlaws: As I said above, there were two major flaws in the study.

Flaw #1: The study did not identify the dose of supplement used. This is important because the increased risk of atrial fibrillation and stroke is primarily seen in clinical trials using high dose omega-3 supplements.

Flaw #2: This was an association study which cannot prove cause and effect. However, the authors of this study reported it as showing that omega-3 supplement use caused atrial fibrillation and stroke – and all the news reports on the study have repeated that claim.

Flaw #3: Other experts have pointed out that the authors inflated the risks associated with omega-3 supplementation by reporting relative risk rather than absolute risk. Let me try to simplify the distinction.

The risk of atrial fibrillation was 4.24% in the non-supplement users and 4.80% in the omega-3 supplement users. That is an absolute increase in risk of 0.56% (4.80% – 4.24%). This is the increase in risk you actually experience. In contrast, 4.80% is 13% greater than 4.24%, which is how relative risk is calculated.

In response to the questions you are probably thinking:

  • Yes, this is a perfect example of the Mark Twain quote, “There are lies. There are damn lies. And then there are statistics.”
  • Yes, all the percentages reported in this study are based on relative risk and are, therefore, inflated. However, I do not have access to their data, so I cannot tell you the absolute risk associated with their other observations.

Blind Spots: In their paper the investigators recommended against the use of omega-3 supplements to prevent heart disease because their data showed:

  • No benefit of omega-3 supplementation for preventing major cardiovascular events and deaths in a healthy population.
  • But did suggest an increased risk of atrial fibrillation and stroke in that same population.

However, their blind spot was in underestimating the difficulty of showing the benefit of any intervention in a healthy population. The example I always use is statin drugs. Statin Drugs:

  • Dramatically reduce the risk of a second heart attack and/or death in people who have already had a heart attack.
  • Reduce the risk of heart attacks in people who are at high risk of heart attacks.
  • Cannot be shown to reduce the risk of heart attacks in a healthy population.

This study suggests that omega-3 supplements are no different. In this study, omega-3 supplements:

  • Reduced the risk of death in people who had already experienced a major cardiovascular event like a heart attack or stroke.
  • Reduced the risk of major cardiovascular events and death in people with atrial fibrillation, which puts them at high risk for a heart attack or stroke.
  • Could not be shown to reduce the risk of major cardiovascular events or deaths in a healthy population.

Hidden Data: There are some important data that were buried in the text and supplemental figures but were Skepticignored in the concluding remarks of this study and all the articles written about it. For example:

  • The original study and all articles written about the study reported that omega-3 supplementation increased the risk of stroke in otherwise healthy individuals but ignored the observation that omega-3 supplementation decreased the risk of heart failure in that same group.

The second example of hidden data likely represents another blind spot of the authors. They concluded that omega-3 supplementation had no benefit for healthy individuals without asking whether omega-3 supplements might benefit higher-risk subpopulations within this group. To help you understand this statement let me start by giving you some perspective.

As I said above, statin drugs cannot be shown to reduce the risk of heart attacks in a healthy population. But when you include people at high risk of heart disease with healthy people in the dataset, you start to see a reduced risk of heart attacks.

Similarly, with supplements you often see no benefits with the general population, which is what is usually reported in the media. But when you look at higher risk groups within that population, the benefits of supplementation emerge.

This study is no different:

  • For healthy individuals, omega-3 supplementation had no effect on deaths during the 12-year follow-up period.
  • However, omega-3 supplementation reduced the risk of death by 9% for both men and people ≥ 65. These represent two groups with elevated risk of heart disease within the otherwise healthy population.
  • Once again, these data were completely ignored.

What Does This Study Mean For You?

This study made 3 major points:

Point #1: Let me start with the one you’ve heard the most about. The risk of atrial fibrillation and stroke associated with omega-3 supplementation is real. We should not ignore it.

But what this study and most of the reports on the study didn’t tell you is that the risk is dose dependent. The risk is primarily seen with high doses of omega-3s. While no one has done a comprehensive dose response analysis, I can tell you that these side effects are:

  • Seldom reported in clinical studies at doses of 1 gm/day or less.
  • Sometimes reported in clinical studies at doses of ≥2 gm/day.
  • Frequently reported in clinical studies at doses of ≥4 gm/day.

However, atrial fibrillation and stroke occur in a very small percentage of omega-3 users, even at 4 gm/day. At this point we have no idea why some people are susceptible to these side effects and others are not. More research in this area is clearly needed.

Until we know more about who is at risk, my recommendation for people who are trying to reduce the risk of heart disease is to rely on something called the Omega-3 Index to determine your individual omega-3 needs rather than using high-dose omega-3 supplements.

  • The Omega-3 Index measures the amount of omega-3 fatty acids in your tissues. It is determined by the amount of omega-3s you consume and how you metabolize them, so it is individualized to you.
  • An Omega-3 Index of 4% is associated with a high risk of heart disease, while an Omega-3 Index of 8% is associated with a low risk of heart disease. There is no evidence that more than 8% provides additional benefit.
  • Most importantly, it only takes 1-1.6 gm/day of omega-3s to raise your Omega-3 Index from 4% to 8%. At these doses your risk of atrial fibrillation and stroke is extremely small.

For example, a recent meta-analysis of 29 studies with a total of 183,292 participants reported that people with an 8% Omega-3 Index had:

  • Decreased risk of ischemic stroke (stroke due to blood clots) with no detectable increased risk of hemorrhagic stroke (stroke due to bleeding), and…
  • No detectable increased risk of atrial fibrillation.

I recommend getting your Omega-3 Index determined, and if it is low, increasing your omega-3 intake to get it into the 8% range. Some people go from 4% to 8% more rapidly than others, so you may need to repeat the test several times to optimize your Omega-3 Index.

If your health professional doesn’t have access to the Omega-3 Index test, you can order it from https://omegaquant.com (I have no financial stake in this company, but I know it as a reputable source of the Omega-3 Index test).

Does The Professor Plan To Reduce His Intake Of Omega-3 Fatty Acids? Three weeks ago, I shared thatprofessor owl my wife and I have been taking around 3 gm/day of omega-3 supplements for the past 40 years. Now that the association of atrial fibrillation and stroke with high dose omega-3 intake has been firmly established, some of you may be wondering whether we plan to decrease our intake of omega-3 supplements.

The answer is, “No”. Remember that the increased risk of atrial fibrillation and stroke is only seen for a small subset of people taking high-dose omega-3 supplements. If we were part of that subset, we would likely have experienced one of those side effects by now.

However, if you are considering omega-3 supplementation for the first time, you don’t know whether you are part of that subset or not. So, my advice remains the same. Rely on optimizing your Omega-3 Index rather than high-dose omega-3 supplementation.

Point #2: Healthy individuals (those with no symptoms of heart disease) do not benefit from omega-3 supplementation. As I pointed out above, this ignores data from their study, namely.

  • Omega-3 supplementation reduced the risk of heart failure in healthy subjects.
  • Omega-3 supplementation reduced the risk of death in higher risk groups within the healthy population (namely men and people 65 and older).

Confusion Clinical StudiesAs I discussed above, this is a pattern seen with statin drugs and most nutritional supplements. Simply put, you can’t show any benefit of statin drugs or most nutritional supplements in a “healthy” population, but you can show benefit when you focus on higher risk individuals within the “healthy” population.

The problem, of course, is that most of us don’t really know whether we are “healthy” or not. For millions of Americans the first indication that they are at risk from heart disease is sudden death from a heart attack or stroke.

With that in mind, I will leave the decision about whether you want to supplement with omega-3s up to you. But if you decide to supplement, I recommend you optimize your Omega-3 Index rather than using a high dose omega-3 supplement.

Point #3: People with heart disease benefit from omega-3 supplementation. This recommendation is becoming non-controversial, so I won’t comment further other than to say high dose omega-3 supplements are probably not needed unless prescribed by your health professional.

The Bottom Line

You have been asking me about recent headlines saying that omega-3 supplements may increase rather than decrease the risk of heart disease. So, I analyzed the study behind the headlines. The study makes 3 claims:

  • Omega-3 supplements increase the risk of atrial fibrillation and stroke when taken by healthy people.
  • Omega-3 supplements are of no benefit for healthy individuals.
  • Omega-3 supplements are beneficial for people who have heart disease.

In the article above I review the flaws, blind spots, and hidden data in the article and discuss what it means for you.

For more details about this study and what it means for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 _______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Is The Mediterranean Diet Healthy For Women?

by

What Does This Study Mean For You? 

Author: Dr. Stephen Chaney 

There is a well-known health disparity in clinical studies related to health. For years most of the studies have been done by men for men. Women have been assumed to experience the same benefits and risks from diet choices as men. But that hasn’t always proven to be true.

The Mediterranean diet is no exception. For example, it has garnered a reputation of reducing heart disease risk for both men and women.

However, most studies on the Mediterranean diet have included primarily male participants or did not report sex specific differences in outcomes.

And the few studies that reported sex specific outcomes have been inconsistent.

  • Some studies have found that men and women benefitted equally from the Mediterranean diet.
  • Other studies have reported that men benefitted more than women.

However, these were all small studies. No meta-analyses have been reported that focused on the heart benefits of the Mediterranean diet for women.

The study (A Pant et al., Heart; 109: 1208-1215, 2023) I will describe today was designed to fill that gap.

How Was The Study Done?

clinical studyThe investigators started by screening the literature to find studies that:

  • Measured adherence to the Mediterranean diet using the original MDS (Mediterranean Diet Score) or more recent modifications of the MDS.
  • Included women ≥18 years without previous diagnosis of clinical or subclinical heart disease.
  • Performed the study with only women participants or organized their data so that the data pertaining to women could be extracted from the study.

The investigators then performed a meta-analysis on data from 722,495 women in 16 studies published between 2006 and 2021 that met these criteria. These studies followed the women for an average of 12.5 years. The studies were primarily conducted in the United States and Europe.

The individual studies divided participants into either quintiles or quartiles and compared participants with the highest adherence to the Mediterranean diet to those with the lowest adherence.

  • The primary outcomes measured were total mortality and the incidence of CVD, cardiovascular disease (defined as including CHD (coronary heart disease), myocardial infarction (heart attack), stroke, heart failure, and cardiovascular death).
  • The secondary outcomes measured were stroke and CHD, coronary heart disease (heart disease caused by atherosclerotic plaque build up in the coronary arteries).

Is The Mediterranean Diet Healthy For Women?

Mediterranean Diet FoodsWhen comparing the highest to the lowest adherence to the Mediterranean diet:

  • The incidence of CVD (cardiovascular disease) was reduced by 24%.
  • Total mortality during the ~12.5-year follow-up was reduced by 23%.
  • The incidence of CHD (coronary heart disease) was reduced by 25%.
  • The risk of stroke was reduced by 13%, but that risk reduction was not statistically significant.
    • The risk reduction for both CVD and total mortality was similar to that previously reported for men.
    • Risk reduction for CVD was slightly higher for women of European descent (24%) than for women of non-European descent (21%). The later category included women of Asian, Native-Hawaiian, and African – American descent.

The authors concluded, “This study supports a beneficial effect of the Mediterranean diet on the primary prevention of CVD and death in women and is an important step in enabling sex-specific guidelines.”

I would add that the data from women of non-European decent suggests that genetic background and/or ethnicity may influence the effectiveness of the Mediterranean diet at reducing heart disease risk, but this effect appears to be small.

What Does This Mean For You?

The results of this study are not unexpected. But that doesn’t mean that studies with women are not valuable. There have been several examples in recent years where health or medical advice based on studies with men needed to be modified for females once the studies were repeated with women.

Before covering what this study means for you, I should point out that while women often fear breast cancer most, heart disease is their number one killer, as the graph on the left shows. In fact, a woman’s risk of dying from coronary heart disease is 6 times greater than her risk of dying from breast cancer.

This study shows that following a Mediterranean–style diet lowers their risk of developing and dying from heart disease. But the Mediterranean diet is not alone in providing these health benefits. It is simply a whole food, primarily plant-based diet that reflects the food preferences of the Mediterranean region.

The DASH diet, which reflects the food preferences of Americans, and the Nordic diet, which reflects the food preferences of the Scandinavian countries, are equally heart healthy. In fact, any whole food, primarily plant-based diet will reduce the risk of heart disease. You should choose the one that best fits your food preferences and lifestyle.

Of course, diet is just part of a holistic approach for reducing heart disease risk. Other important risk reduction strategies include:

  • Don’t smoke.
  • Exercise and maintain a healthy weight.
  • Manage stress.
  • Avoid or limit alcohol.
  • Know your numbers (cholesterol, triglycerides, and blood pressure, for example).
  • Manage other health conditions that increase the risk of heart disease (high blood pressure, diabetes, and high cholesterol, for example).

The Bottom Line

Most studies on the heart health benefits of the Mediterranean diet have been done with men or have not analyzed the data from men and women separately. A recent meta-analysis combining data from 16 studies with 722,495 women showed that the Mediterranean diet was just as heart healthy for women as it was for men.

The authors concluded, “This study supports a beneficial effect of the Mediterranean diet on the primary prevention of CVD and death in women and is an important step in enabling sex-specific guidelines.”

For more details on this study and information on other diets that are heart healthy, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

_____________________________________________________________________________My My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 _____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Do Omega-3s Improve Recovery From A Heart Attack?

by

Where Do We Go From Here? 

Author: Dr. Stephen Chaney 

Omega-3s And Heart DiseaseDespite years of controversy, the benefits of omega-3s remain an active area of research. Over the next few weeks, I will review several groundbreaking omega-3 studies. This week I will focus on omega-3s and heart health.

I don’t need to tell you that the effect of omega-3s on heart health is controversial. One month a new study is published showing an amazing health benefit from omega-3 supplementation. A month or two later another study comes up empty. It finds no benefit from omega-3 supplementation.

That leads to confusion. On one hand you have websites and blogs claiming that omega-3s are a magic elixir that will cure all your ills. On the other hand, there are the naysayers, including many health professionals, claiming that omega-3 supplements are worthless.

I have discussed the reasons for the conflicting results from omega-3 clinical studies in previous issues of “Health Tips From the Professor”. You can go to https://www.chaneyhealth.com/healthtips/ and put omega-3s in the search box to read some of these articles.

Or if you prefer, I have also put together a digital download I call “The Omega-3 Pendulum” which briefly summarizes all my previous articles. It’s available on my Chaney Health School Teachable website.

Today I will discuss a study (B Bernhard et al, International Journal of Cardiology, 399; 131698, 2024) that asks whether 6 months of high dose omega-3 supplementation following a heart attack reduced the risk of major cardiovascular events over the next 6.6 years.

You might be wondering why the study didn’t just look at the effect of continuous omega-3 supplementation for 6 years following a heart attack. There are two very good reasons for the design of the current study.

1) The investigators wanted to do a double blind, placebo controlled clinical trial, the gold standard for clinical studies. However, that kind of study is impractical for a multi-year clinical trial. It would be prohibitively expensive, and patient compliance would be a big problem for a study that long.

2) The months immediately after a heart attack are critical in determining the long-term recovery of that patient. There is often a period of massive inflammation following a heart attack. And that can lead to further damage to the heart and reclosing of the arteries leading to the heart, both of which increase the risk of future adverse cardiac events.

Previous studies have shown that high dose omega-3s immediately following a heart attack can reduce inflammation and damage to the heart. However, those studies did not determine whether the cardioprotective effect of omega-3 supplementation immediately after a heart attack lead to improved long-term outcomes, something this study was designed to determine.

How Was The Study Done?

clinical studyThe investigators enrolled 358 patients who had suffered a heart attack from three Boston area medical centers between June 2008 and August 2012.

The patient demographics were:

  • Gender = 70% female.
  • Average age = 59
  • Average BMI = 29 (borderline obese).
  • Patients with high blood pressure = 64%
  • Patients with diabetes = 25%.

The patients were divided into two groups. The first group received capsules providing 4 gm/day of EPA, DHA, and other naturally occurring omega-3 fatty acids. The other group received a placebo containing corn oil. This was a double-blind study. Neither the patients nor the investigators knew which patients received the omega-3 fatty acids and which ones received the placebo.

The patients were instructed to take their assigned capsules daily for 6 months. At the beginning of the study, blood samples were withdrawn to determine the percentage of omega-3s in the fatty acid content of their red cell membranes (something called omega-3 index). Patients were also tested for insulin resistance and given a complete cardiovascular workup. This was repeated at the end of the 6-month study.

[Note: Previous studies have shown that an omega-3 index of 4% or lower is associated with high risk of heart disease, and an omega-3 index of 8% or above is associated with a low risk of heart disease.]

At 2-month intervals the patients were contacted by staff using a scripted interview to determine compliance with the protocol and their cardiovascular health. Once the 6 months of omega-3 supplementation was completed, the patients were followed for an additional 6.6 years. They were contacted every 6 months for the first 3 years and yearly between 3 years and 6 years.

The investigators quantified the number of major cardiac events (defined as recurrent heart attacks, the necessity for recurrent coronary artery bypass grafts, hospitalizations for heart failure, and all-cause deaths) for each patient during the 6.6-year follow-up period.

Patients in both groups were treated according to current “standard of care” protocols which consisted of diet and exercise advice and 5-6 drugs to reduce future cardiovascular events.

Do Omega-3s Improve Recovery From A Heart Attack?

heart attacksWhen the investigators looked at the incidence of adverse cardiac events during the 6.6-year follow-up period, there were three significant findings from this study.

1) There were no adverse effects during the 6-month supplementation period with 4 gm/day of omega-3s. This is significant because a previous study with 4 gm/day of high purity EPA had reported some adverse effects which had led some critics to warn that omega-3 supplementation was dangerous. More study is needed, but my hypothesis is that this study did not have side effects because it used a mixture of all naturally occurring omega-3s rather than high purity EPA only. 

However, this could also have been because of the way patients were screened before entering this study. I will discuss this in more detail below.

2) When the investigators simply compared the omega-3 group with the placebo group there was no difference in cardiovascular outcomes between the two groups. This may have been because this study faced significant “headwinds” that made it difficult show any benefit from supplementation. I call them “headwinds” rather than design flaws because they were unavoidable. 

    • It would be unethical to deny the standard of care to any patient who has just had a heart attack. That means that every patient in a study like this will be on multiple drugs that duplicate the beneficial effects of omega-3 fatty acids – including lowering blood pressure, lowering triglycerides, reducing inflammation, and reducing plaque buildup and blood clot formation in the coronary arteries.

That means that this study, and studies like it, cannot determine whether omega-3 fatty acids improve recovery from a heart attack. They can only ask whether omega-3 fatty acids have any additional benefit for patients on multiple drugs that duplicate many of the effects of omega-3 fatty acids. That significantly reduces the risk of a positive outcome.

    • As I mentioned above, it would have been impractical to continue providing omega-3 supplements and placebos during the 6.6-year follow-up.

And the study was blinded, meaning that the investigators did not know which patients got the omega-3s and which patients got the placebo. That meant the investigators could not advise the omega-3 supplement users to continue omega-3 supplementation during the follow-up period.

Consequently, the study could only ask if 6 months of high-dose omega-3 supplementation had a measurable benefit 6.6 years later. I, for one, would be more interested in knowing whether lower dose omega-3 supplementation continued for the duration of this study reduced the risk of major coronary events.good news

3) When the investigators compared patients who achieved a significant increase in their omega-3 index during the 6-month supplementation period with those who didn’t, they found a significant benefit of omega-3 supplementation.

This was perhaps the most significant finding from this study.  

If the investigators had stopped by simply comparing omega-3 users to the placebo, this would have been just another negative study. We would be wondering why it did not show any benefit of omega-3 fatty acid supplementation.

However, these investigators were experts on the omega-3 index. They knew that there was considerable individual variability in the efficiency of omega-3 uptake and incorporation into cell membranes. In short, they knew that not everyone taking a particular dose of omega-3s will achieve the same omega-3 index.

And that is exactly what they saw in this study. All the patients in the 6-month omega-3 group experienced an increase in omega-3 index, but there was considerable variability in how much the omega-3 index increased over 6 months.

So, the investigators divided the omega-3 group into two subgroups – ones whose omega-3 index increased by ≥ 5 percentage points (sufficient to move those patients from high risk of heart disease to low risk) and ones whose omega-3 index increased by less than 5 percentage points.

When the investigators compared patients with ≥ 5% increase in omega-3 index to those with <5% increase in omega-3 index:

  • Those with an increase in omega-3 index of ≥ 5% had a 2.9% annual risk of suffering major adverse cardiac events compared to a 7.1% annual risk for those with an increase of <5%.
  • That’s a risk reduction of almost 60%, and it was highly significant.

The authors concluded, “In a long-term follow-up study, treatment with [high dose] omega-3s for 6 months following a heart attack did not reduce adverse cardiac events compared to placebo. However, those patients who were treated with omega-3s and achieved ≥ 5% rise in omega-3 index experienced a significant reduction of adverse cardiac events after a median follow-up period of 6.6 years…Additional studies are needed to confirm this association and may help identify who may benefit from omega-3 fatty acid treatment following a heart attack.”

What Does This Study Mean For You? 

Questioning WomanI should start by saying that I do not recommend 4 gm/day of omega-3 fatty acids following a heart attack without checking with your doctor first.

  • If you are on a blood thinning medication, the dose of either the medication or the omega-3 supplement may need to be reduced to prevent complications due to excess bleeding.
  • In addition, the investigators excluded patients from this study who might suffer adverse effects from omega-3 supplementation. This is a judgement only your doctor can make.

With that advice out of the way, the most important takeaway from this study is that uptake and utilization of omega-3 fatty acids varies from individual to individual.

The omega-3 index is a measure of how well any individual absorbs and utilizes dietary omega-3s. And this study shows that the omega-3 index is a much better predictor of heart health outcomes than the amount of omega-3 fatty acids a person consumes.

This is not surprising because multiple studies have shown that the omega-3 index correlates with heart health outcomes. It may also explain why many studies based on omega-3 intake only have failed to show a benefit of omega-3 supplementation.

Vitamin D supplementation is a similar story. There is also considerable variability in the uptake of vitamin D and conversion to its active form in the body. 25-hydroxy vitamin D levels in the blood are a marker for active vitamin D. For that reason, I have long recommended that you get your 25-hydroxy vitamin D level tested with your annual physical and, with your doctor’s help, base the dose of the vitamin D supplement you use on that test.

This study suggests that we may also want to request an omega-3 index test and use it to determine the amount of supplemental omega-3s we add to our diet.

Where Do We Go From Here?

Where Do We Go From HereThe idea that we need to use the omega-3 index to determine the effectiveness of the omega-3 supplement we use is novel. As the authors suggest, we need more studies to confirm this effect. There are already many studies showing a correlation of omega-3 index with heart health outcomes. But we need more double blind, placebo-controlled studies like this one.

More importantly, we need to understand what determines the efficiency of supplemental fatty acid utilization so we can predict and possibly improve omega-3 utilization. The authors suggested that certain genetic variants might affect the efficiency of omega-3 utilization. But the variability of omega-3 utilization could also be affected by:

  • Diet, especially the presence of other fats in the diet.
  • Metabolic differences due to obesity and diseases like diabetes.
  • Gender, ethnicity, and age.
  • Design of the omega-3 supplement.

We need much more research in these areas, so we can personalize and optimize omega-3 supplementation on an individual basis.

The Bottom Line 

A recent study asked whether high dose omega-3 supplementation for 6 months following a heart attack reduced major cardiac events during the next 6.6 years.

  • When they simply compared omega-3 supplementation with the placebo there was no effect of omega-3 supplementation on cardiac outcomes.
  • However, when they based their comparison on the omega-3 index (a measure of how efficiently the omega-3s were absorbed and incorporated into cell membranes), the group with the highest omega-3 index experienced a 60% reduction in adverse cardiac events over the next 6.6 years.

This is consistent with multiple studies showing that the omega-3 index correlates with heart health outcomes.

More importantly, this study shows there is significant individual variation in the efficiency of omega-3 absorption and utilization. It also suggests that recommendations for omega-3 supplementation should be based on the omega-3 index achieved rather than the dose or form of the omega-3 supplement.

For more information on this study and what it means for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are Calcium Supplements Heart Healthy?

by

Should You Follow Your Doctor’s Advice About Calcium Supplementation?

Author: Dr. Stephen Chaney

Heart ConfusionAre calcium supplements good for your heart or bad for your heart? If you don’t know the answer to that question, don’t feel badly. You have every right to be confused. Some studies say that calcium supplements increase heart disease risk while others say they decrease heart disease risk. The headlines have veered between “killer calcium” and “beneficial calcium”.

The trend appears to be moving in a positive direction. In recent years most of the studies have suggested that calcium supplements either decrease heart disease risk or have no effect on heart disease risk.

However, the medical profession has been slow to take note of this trend. Most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements. I will talk more about that recommendation below.

With this context in mind, this week I will review and discuss the results from the latest study (MG Sim et al, Heart, Lung and Circulation, 32: 1230-1239, 2023) on the effect of calcium supplementation on heart disease risk.

How Was This Study Done?

Clinical StudyThe authors of this study performed a meta-analysis of 12 double-blinded randomized clinical trials with 87,899 participants comparing the effect of a calcium supplement versus a placebo on heart disease outcomes (heart attack, stroke, heart failure, cardiovascular mortality, and all-cause mortality).

The studies included in this analysis:

  • Used calcium doses from 500 mg/day to 2,000 mg/day.
  • Used supplements with calcium coming from a variety of sources (calcium carbonate, calcium citrate, calcium gluconolactate, and tricalcium phosphate).
  • Ranged from 18 months to almost 12 years in length.
  • Were performed with population groups from a wide range of countries (United States, England, France, Australia, New Zealand, European Union, Denmark, and Thailand).
  • Included calcium supplements with and without vitamin D.
  • Were primarily (86% of participants) conducted with post-menopausal women. One small study (0.3% of participants) was conducted with non-osteoporotic men. The rest were conducted with mixed populations (men and women) diagnosed with colorectal adenoma.

Are Calcium Supplements Heart Healthy?

calcium supplementsThis is the largest meta-analysis performed to date of double-blind, placebo-controlled randomized clinical trials on the effect of calcium supplementation versus a placebo on heart disease outcomes. This study found no effect of calcium supplementation on:

  • Heart attack.
  • Stroke
  • Heart failure.
  • Cardiovascular mortality.
  • All-cause mortality.

This study also evaluated potential confounding variables and found no effect of calcium supplementation on heart disease risk for:

  • Calcium supplements with and without vitamin D.
  • Dosage of calcium in the supplements (The dosage ranged from 500 mg/day to 2,000 mg/day).
  • Females (I suspect the number of males in this study was too small to come to a statistically significant conclusion).
  • Duration of calcium supplementation ≤ 5 years (The shortest duration of calcium supplementation in these studies was 18 months).
  • Different geographical regions.

However, this meta-analysis reported considerable variation between studies included in the analysis. Simply put,

  • Some studies showed an increase in heart disease risk.
  • Some studies showed a decrease in heart disease risk.
  • Some studies showed no effect on heart disease risk.

What this analysis showed was that when you combine all the studies, the aggregated data is consistent with calcium supplementation having no effect on heart disease risk.

The authors concluded, “Calcium supplementation was not associated with myocardial infraction [heart attack], stroke, heart failure, and cardiovascular/all-cause mortality. Further studies are required to examine and understand these associations.

Should You Follow Your Doctor’s Advice About Calcium Supplementation?

Doctor With PatientAs I said above, most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements. That may be the advice you are getting from your doctor.

Before you assume your doctor isn’t keeping up with the latest science and ignore his or her advice, we should ask why they are giving that advice. The top three reasons most medical societies give for recommending dietary sources of calcium are:

1) Some studies do show an increased risk of heart disease associated with calcium supplementation. The prime directive for health professionals is to do no harm. Yes, the average of all studies shows no effect of calcium supplementation on heart disease risk. But what if the studies showing increased risk are true for some of their patients? Those patients could be harmed. 

Are you someone who might be at increased risk for heart disease if you take calcium supplements. The short answer is we don’t know because previous studies have not asked the right questions. 

In my opinion, it is time to pause additional studies and meta-analyses on calcium supplementation and heart health until we have gone over existing studies with a fine-tooth comb to figure out why the results differ so wildly. For example, we need to ask whether the effect of calcium supplements on heart disease risk is influenced by things like:

    • Age or ethnicity of participants.
    • Other preexisting health conditions.
    • Other lifestyle factors (exercise is probably the most important, but others may be involved as well).
    • Diet context. For example, we already know that the effect of eggs and dairy on heart health is influenced by diet context. [I have covered this for eggs in a previous issue of “Health Tips From the Professor”.]
    • Other unanticipated variables.

Only when we have identified variables that might influence the effect of calcium supplements on heart disease risk, will the scientific community be able to design studies to identify the population groups who might be adversely affected by calcium supplementation.

This would allow health professionals to make informed decisions about which of their patients should avoid calcium supplementation and which of their patients would benefit from calcium supplementation. 

2) We really don’t need the recommended RDAs for calcium to build strong bones. The Healthy Bonerecommended RDAs for calcium are 1,000 mg/day for adults 19-50, 1,000 mg/day for men and 1,200 mg/day for women 51-70, and 1,200 mg/day for both men and women over 70. But do we really need that amount of calcium to build healthy bones? 

I have discussed this topic in detail in a previous issue of “Health Tips From the Professor”. Here are the key points:

    • The current RDAs are based on calcium needs for people consuming the typical American diet and following the typical American lifestyle. If that is you, the current RDAs probably apply.
    • However, strong bones are absolutely dependent on three things, adequate calcium, adequate vitamin D, and adequate weight-bearing exercise. Most recent studies of calcium supplementation and bone density include adequate vitamin D, but almost none of them include exercise. Previous studies have been inadequate.
    • The best calcium supplements contain certain nutrients besides vitamin D that optimize bone formation. I have listed those nutrients in the article cited above.
    • Our ability to use calcium to build strong bones is dependent on diet (something I call a bone-healthy diet) and lifestyle (something I call a bone-healthy lifestyle).
    • For more information on each of these points, read the article I referenced above.

In short, I agree that the current calcium RDAs may be too high for individuals consuming a bone-healthy diet and following a bone-healthy lifestyle. But the current calcium RDAs are likely accurate for people consuming the typical American diet and following the typical American lifestyle.

    • While we do not have a calcium RDA for populations following a bone healthy diet lifestyle, some studies suggest that 700-800 mg of calcium/day may be sufficient for this group.

3) Calcium from supplements is absorbed faster and gives higher blood level spikes than calcium from foods. That could be a problem because high blood levels of calcium are associated with calcification of our arteries, which is associated with increased heart disease risk. 

This is a theoretical concern, because high blood calcium levels from supplementation are transitory, while it is continuous high blood calcium levels that are associated with calcification of our arteries.

However, it is a plausible concern because most supplement companies design their calcium supplements based on how quickly they get calcium into the bloodstream rather than how effectively the calcium is utilized for bone formation. Here are my recommendations:

    • Choose a calcium supplement that provides RDA levels of vitamin D plus other nutrients shown to support strong bone formation.
    • Choose a calcium supplement supported by clinical studies showing it is effectively utilized for bone formation.

4) We should be getting our calcium from foods rather than supplements. dairy foods

While it is always easy for doctors to recommend that we get our nutrients from food rather than supplements, they need to ask whether we are getting those nutrients from our diet. For calcium the data are particularly sobering.

    • The average American gets around 740 mg of calcium/day from their diet. That is probably enough for the small percentage of Americans following a bone healthy diet and lifestyle. But it is 260-460 mg short of the 1,000-1,200 mg/day recommended for older adults with the typical American diet and lifestyle.
      • And for the average American, around 70% of their calcium intake comes from dairy foods.

       

      • So, Americans who are following a typical American diet and lifestyle and are restricting dairy may require 800-1,000 mg/day of supplemental calcium unless they carefully plan their diets to optimize calcium intake.

       

      • Finally, vegans average about 550 mg/day from their diet. That might be borderline even if they were following a bone healthy lifestyle.
    • In short, we cannot assume our diet will provide enough calcium for strong bones unless we include dairy foods and/or plan our diet very carefully. Some degree of supplementation may be necessary.

How Much Calcium Do You Need?

Questioning Woman

I have covered a lot of territory in this article, so let me summarize the four concerns of the medical community and answer your most important question, “Should you take calcium supplements?”

1) Calcium supplements may increase the risk of heart disease for some people.

That is true, but we have no idea at present who is at increased risk and who isn’t. So, we should minimize our risk by taking the precautions I describe below.

2) We don’t need RDA levels of calcium to build strong bones. That is probably true if you are one of the few people who follows a bone healthy diet and lifestyle, but it isn’t true if you follow the typical American diet and lifestyle.

  • The current RDAs of 1,000 – 1,200 mg/day are a good guideline for how much calcium you need if you follow the typical American diet and lifestyle.
  • If you a one of the few people who follow a bone healthy diet and lifestyle (For what that involves, read this article) you may only need 700-800 mg/day. But we don’t have clinical studies that can tell us what the actual RDA for calcium should be under those circumstances.

3) Calcium from supplements is absorbed faster and gives higher blood calcium spikes than calcium from foods. You may remember that the theoretical concern is that even short-term spikes of high blood calcium may lead to calcification of your arteries, which increases your risk of heart disease. So, the important question becomes, “What can we do to minimize these spikes in blood calcium levels?”

  • We should avoid calcium supplements that brag about how quickly and efficiently the calcium is absorbed. That could lead to calcium spikes. Instead, we should look for calcium supplements that are backed by clinical studies showing they are efficiently utilized for bone formation.
  • We should look for calcium supplements that include RDA levels of vitamin D and other nutrients that optimize bone formation. You will find more information on that in the same article I referenced above.
  • Some experts recommend that calcium supplements be taken between meals. But it is probably better to take them with meals because foods will likely slow the rate at which calcium is absorbed and reduce calcium spikes in the blood.
  • We are told to limit calcium supplements to less than 500 mg at any one time because calcium absorption becomes inefficient at higher doses. It might be even better to limit calcium to 250 mg or less at a time to reduce calcium spikes in the blood.

4) We should get calcium from foods rather than supplements.

  • Many Americans do not get enough calcium from diet alone, especially if they avoid dairy foods. So, some degree of calcium supplementation may be necessary. I have given some guidelines depending on your diet and lifestyle above.
  • The amount of supplemental calcium needed is relatively small. I do not recommend exceeding the RDA unless directed to by your health professional.

The Bottom Line 

Some studies say that calcium supplements increase heart disease risk while others say they decrease heart disease risk. The headlines veer between “killer calcium” and “beneficial calcium”.

The trend appears to be moving in a positive direction. In recent years most of the studies have suggested that calcium supplements either decrease heart disease risk or have no effect on heart disease risk.

However, the medical profession has been slow to take note of this trend. Most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements.

A recent meta-analysis of 12 double-blinded randomized clinical trials with 87,899 participants comparing the effect of a calcium supplement versus a placebo on heart disease outcomes has just been published. This study found no effect of calcium supplementation on:

  • Heart attack.
  • Stroke.
  • Heart failure.
  • Cardiovascular mortality.
  • All-cause mortality.

The authors of the study concluded, “Calcium supplementation was not associated with myocardial infraction [heart attack], stroke, heart failure, and cardiovascular/all-cause mortality.

For more details and advice on whether you should follow your doctor’s recommendations for calcium supplementation read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 _____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

____________________________________________________________________

About The Author

Dr. Steve ChaneyDr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

 

Is Whole Fat Dairy Healthy?

by

Is It Dairy Or Diet?

Author: Dr. Stephen Chaney 

CheesesFor years we have been told to select low fat dairy foods. But recent headlines claim, “That’s nonsense. Whole fat dairy foods are healthy.” Are those headlines true?

In previous issues of “Health Tips From the Professor” I have kept you abreast of recent studies suggesting that whole fat dairy foods may not be as bad for us as we thought. I also cautioned you that the headlines may not have accurately represented the studies they described.

Headlines have to be simple. But truth is often more nuanced. If we believed the current headlines, we might be asking ourselves questions like, “Should we ditch the current health guidelines recommending low-fat dairy foods? Are foods like ice cream, sour cream, and cheddar cheese actually be good for us?

To answer these questions, I will look at the study (A Mente et al, European Heart Journal, 44, 2560-2579, 2023) behind the current headlines and put the study into perspective.

Spoiler alert: If I could summarize the study findings in two sentences, they would be, “Whole fat dairy can be part of a healthy diet. But can it be part of an unhealthy diet?”

Stay tuned. I will discuss the science behind that statement below.

How Was This Study Done?

clinical studyThis study started with data collected from the Prospective Urban Rural Epidemiology (PURE) study. The PURE study is an ongoing study correlating diet, lifestyle, and environmental effects on health outcomes. It has enrolled 166,762 individuals, age 35-70, from 21 low-, middle-, and high-income countries on 5 continents.

Habitual food intake was determined using country-specific food frequency questionnaires at the time participants joined the study. Participants (166,762) from the PURE study who had complete dietary information were included in this study and were followed for an average of 9.3 years.

Based on preliminary analysis of data from the PURE study, the authors developed their version of a healthy diet, which they call the PURE diet. Like most other healthy diets, the PURE diet emphasizes fruits, vegetables, legumes, nuts, and fish. However:

  • Based on studies suggesting that whole fat dairy foods can be part of a healthy diet, the PURE diet includes whole fat dairy foods.

This is different from most other healthy diet recommendations.

They went on to develop what they referred to as the PURE healthy diet score by:

  • Determining the median intake for each of the 6 food groups included in their PURE diet (fruits, vegetables, legumes, nuts, fish, and whole fat dairy).
  • Assigning each participant in the study a score of 0 or 1 depending on whether their intake for that food group was below or above the median intake.
  • Adding up the points. Since 6 food groups were included in the PURE diet, this means that each participant in the study was assigned a PURE diet score ranging from 0-6.

Once they had developed a PURE diet score, they expanded their data by including five additional large independent studies that included people from 70 countries. The combined data from all six studies amounted to 245,597 people from 80 countries. Of the people included in the data analysis:

  • 21% came from high income countries.
  • 60% came from middle income countries.
  • 19% came from low-income countries.

This is very similar to the global population distribution. This is a strength of this study because it allowed them to ask whether the PURE diet score worked as well in low-income countries as in high-income countries.

Finally, they correlated the PURE diet score with outcomes like all-cause mortality, heart attack, and stroke.

Is Whole Fat Dairy Healthy?

QuestionsThe authors of this study divided the participants of all 6 studies into quintiles based on their PURE diet score and compared those in the highest quintile (PURE score of ≥ 5) with those in the lowest quintile (PURE score of ≤ 1).

The people in the highest quintile were eating on average 5 servings/day of fruits and vegetables, 0.5 servings/day of legumes, 1.2 servings/day of nuts, 0.3 servings/day of fish, 2 servings/day of dairy (of which 1.4 servings/day was whole fat dairy), 0.5 servings/day of unprocessed red meat, and 0.3 servings/day of poultry.

 

The people in the lowest quintile ate significantly less fruits, vegetables, nuts, fish, and dairy; and slightly less legumes, unprocessed red meat, and poultry than those in the highest quintile.

However, they consumed significantly more refined wheat foods and white rice. This study did not track consumption of highly processed foods, but the high consumption of white flour leads me to suspect they ate a lot more highly processed food.

With that in mind, when the authors compared people with the highest PURE diet scores to those with the lowest PURE diet scores:

  • All-cause mortality was reduced by 30%.
  • Cardiovascular disease was reduced by 18%.
  • Heart attacks were reduced by 14%.
  • Strokes were reduced by 19%.
  • The PURE healthy eating score was slightly better at predicting health outcomes than the Mediterranean, DASH, and HEI (Healthy Eating Index) scores. But the differences were small. So, I still recommend choosing the healthy diet that best fits your preferred foods and your lifestyle.
  • The PURE healthy eating score was significantly better at predicting health outcomes than the Planetary diet score. I will discuss the nutritional inadequacy of “sustainable diets” like the Planetary diet in next week’s “Health Tips From the Professor” article.

Because of the size and design of this study, they were able to make three interesting observations.

  1. The PURE, Mediterranean, DASH, and HEI diet scores were predictive of health outcomes in every country across the globe. You no longer have to wonder if what works in the United States will work in low-income countries and in countries with very different food preferences. Previous studies have not been able to make that claim.

2) You don’t have to be perfect.

    • A 20% increase (one quintile) in PURE score was associated with a 6% lower risk of major cardiovascular events and an 8% lower risk of mortality. In other words, even small improvements in your diet may improve your health outcomes.
    • The health benefits of the PURE diet started to plateau at a score of 3 (with 6 being the highest score). The authors concluded that most of the health benefits were associated with a modestly higher consumption of healthy foods compared to little or no consumption of healthy foods.

Simply put, that means the health benefits gained by going from a moderately healthy diet to a very healthy diet are not as great as the health benefits gained by going from a poor diet to a moderately healthy diet.

[Note: There are still improvements in health outcomes when you go from a moderately healthy diet to a very healthy diet.  My recommendation: “You don’t need to achieve perfection, but you shouldn’t accept mediocrity”.]

3) The PURE diet score was more predictive of health outcomes in some countries than in others.

    • The PURE diet score was more predictive of health outcomes in low-income countries. The authors felt that was because low-income countries started with average PURE scores of 2.1, whereas higher-income countries started with average PURE scores of 3.5.

The authors felt this was another example getting more “bang for the buck” by going from a poor diet to a moderately healthy diet than from a moderately healthy diet to a very healthy diet. (Remember, the health benefits associated with improving PURE diet scores start to plateau at a PURE score of 3.

    • The difference in benefits for low-income countries compared to high-income countries was observed for the Mediterranean, DASH, and HEI diet scores. So, it is probably safe to say for any healthy diet you don’t need to be perfect. You just need to be better.

The authors concluded, “A diet composed of higher amounts of fruit, vegetables, nuts, legumes, fish, and whole fat dairy is associated with a lower risk of cardiovascular disease and mortality in all world regions, especially in countries with lower income where consumption of these foods is low.”

Is It Dairy Or Diet?

CheesesThe headlines are telling us that recommendations to choose low-fat dairy products are out of date. They say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. Let me provide perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context. What do I mean by that? Let’s dig a little deeper into this study.

  • Let’s start with a description of the PURE diet. It is a diet that emphasizes fruits, vegetables, legumes, nuts, and fish. In other words, it is a primarily plant-based diet.
  • Although the authors keep referring to the diet as one that includes whole fat dairy. It would be more accurate to say that it includes dairy, which was 30% low-fat and 70% whole fat.
  • The authors said that removal of any one food group from this combination reduced the predictive power of the PURE diet. In other words, the beneficial effect of 70% whole fat dairy is best seen in the context of a primarily plant-based diet.
  • The PURE diet was most effective at predicting health outcomes in low-income countries where a significant percent of the population consumes a primarily plant-based diet because meats are expensive.

So, a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

To answer that question let’s compare the potential effects of whole fat dairy on a primarily plant-based diet compared to the typical American or European diet.

  • Milk and other dairy foods are excellent sources of calcium, vitamin B12, and iodine and good sources of protein, vitamin D, choline, zinc, and selenium – nutrients that are often low or missing in plant-based diet. And this is true whether the dairy foods are low-fat or whole fat.
  • Primarily plant-based diets tend to be low in saturated fat, so the potential negative effects of adding a small amount of saturated fat to the diet may be outweighed by the beneficial effects of the nutrients dairy foods provide.

On the other hand,

  • The typical American or European diet provides plenty of protein and vitamin B12 and significantly more choline, vitamin D, iodine, and zinc than a plant-based diet. The added nutrients from adding dairy foods to this kind of diet is still beneficial, but the benefits are not as great as adding dairy foods to a primarily plant-based diet.
  • If you read the American Heart Association statement on saturated fats, it does not say that any amount of saturated fat is bad for you. In fact, small amounts of saturated fats play some beneficial roles in our bodies. The American Heart Association says, “Eating too much saturated fat can raise the level of LDL cholesterol in your blood…[which] increases your risk of heart disease and stroke.”
  • Here is where the problem lies. The typical American or European diet already contains too much saturated fat. Whole fat dairy just adds to that excess.

So, the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

The Bottom Line 

Once again, the headlines are telling us that recommendations to choose low-fat dairy products are out of date. The articles say there is no reason to fear whole fat dairy foods. They are good for you. Bring on the ice cream, sour cream, cream cheese, and high fat hard cheeses!

As usual, there is a kernel of truth in the headlines, but headlines have to be simple. And the latest headlines are an oversimplification of what the studies actually show. In this post I looked at the study behind the most recent headlines and provided perspective to the headlines by asking two questions.

#1: Is it dairy or diet? A major weakness of this and similar studies is that they fail to consider diet context.

When you consider diet context a more accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet. But that is too complicated for a headline.

#2: If whole fat dairy can be part of a healthy diet, can it also be part of an unhealthy diet?

When you consider that question the most accurate description of this study would be it shows that a mixture of low-fat and whole-fat dairy foods are a healthy addition to a primarily plant-based diet but may not be a healthy addition to the typical American diet. But that is way too complicated for a headline.

You are probably wondering what this means for you. Here are my recommendations.

If you eat like most Americans, you should continue to follow the current health guidelines to choose low-fat dairy foods.

If you happen to be among the few Americans who eat a primarily plant-based diet, you will probably benefit by adding a mixture of low-fat and whole fat dairy foods to your diet.

For more information on this study, and the science behind my summary of the study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Is HDL Good For Your Heart?

by

Is Everything You Knew About HDL Wrong?

Author: Dr. Stephen Chaney 

HDL CHolesterolIn last week’s “Health Tips From the Professor” I talked about one of the greatest strengths of the scientific method – namely that investigators constantly challenge, and occasionally disprove, existing paradigms. That allows us to discard old models of how things work and replace them with better ones.

Last week I shared a study that disproved the paradigm that low to moderate alcohol consumption is healthier than total abstinence. This week I share several studies that challenge the belief that HDL cholesterol is good for your heart.

The belief that HDL is good for your heart has all the hallmarks of a classic paradigm.

  • It is supported by multiple clinical studies.
  • Elaborate metabolic explanations have been proposed to support the paradigm.
  • It is the official position of most medical societies, scientific organizations, and health information sites on the web.
  • It is the recommendation of most health professionals.
  • It has been repeated so often by so many trusted sources that everyone assumes it must be true.

Once we accept the HDL/heart health paradigm as true, we can construct other hypotheses on that foundation. For example:

  • Raising your HDL levels naturally takes effort. Pharmaceutical companies have been pursuing the “magic pill” that raises HDL levels without any effort on your part.
  • Low carb diets like the Keto and Paleo diets are high in saturated fat. The low carb enthusiasts claim this is a good thing because saturated fat raises HDL levels, and HDL is good for your heart.

But what if the underlying HDL/heart health paradigm weren’t true? These hypotheses would be like the parable of a house built on a foundation of sand. The paradigm will be washed away as soon as it is critically tested.

So, let’s look at experiments that have challenged the HDL/heart health paradigm.

Do Drugs That Increase HDL Levels Work?

The first hint that the HDL/heart health paradigm might be faulty happened when a pharmaceutical company developed a drug that selectively increased HDL levels.

The drug company thought they had found the goose that laid golden eggs. Just imagine. People wouldn’t have to lose weight, exercise, or change their diet. They could simply take a pill and dramatically decrease their heart disease risk. A drug like that would be worth $billions.

The problem was that when they tested their drug (torcetrapib) in clinical trials, it had absolutely no effect on heart disease outcomes (AR Tall et al, Atherosclerosis, Thrombosis, and Vascular Biology 27:257-260, 2007).

The pharmaceutical company couldn’t believe it. Raising HDL levels just had to reduce heart disease risk. They concluded they didn’t have the right drug, and they continued to work on developing new drugs.

That was 16 years ago, and no HDL-increasing drug has made it to market. Have they just not found the right drug, or does this mean the HDL/heart health paradigm is incorrect?

Does Saturated Fat Decrease Heart Disease Risk?

Now let’s turn to two claims of low carb enthusiasts.

#1: Saturated fats decrease your risk of heart disease in the context of a low carb diet. I have debunked that claim in several previous issues of “Health Tips From The Professor”. But let me refer you to two articles here – one on saturated fat and heart disease risk and one on low-carb diets.

#2: Saturated fats decrease heart disease risk because they raise HDL levels. This is the one I will address today.

The idea that saturated fats decrease heart disease risk because they raise HDL levels is based on a simplistic concept of HDL particles. The reality is more complex. Several clinical studies have shown:

  • The type of fat determines the property of the HDL particles.
    • When polyunsaturated fats predominate, the HDL particles have an anti-inflammatory effect. When saturated fats predominate, the HDL particles have a pro-inflammatory effect.
  • Anti-inflammatory HDL particles relax the endothelial cells lining our blood vessels. That makes the lining of our blood vessels more pliable, which improves blood flow and reduces blood pressure.
    • Anti-inflammatory HDL particles also help reduce inflammation of the endothelial lining. This is important because an inflamed endothelial lining is more likely to accumulate fatty plaques and to trigger blood clot formation that can lead to heart attacks and strokes.

So, the question becomes, “What good is it to raise HDL levels if you are producing an unhealthy, pro-inflammatory HDL particle that may increase the risk of high blood pressure, heart attacks, and strokes?”

In short, these studies suggest it isn’t enough to just focus on HDL levels. You need to ask what kind of HDL particles you are creating.

Is HDL Good For Your Heart?

strong heartOnce the studies were published showing that…

  • Drug-induced increase of HDL levels without any change in health habits is not sufficient to decrease heart attack risk, and…
  • Not all HDL particles are healthy. There are anti-inflammatory or pro-inflammatory HDL particles, which likely have opposite effects on heart attack risk…

…some people started to question the HDL/heart health paradigm. And one group came up with the perfect study to test the paradigm.

But before I describe the study, I need to review the term “confounding variables”. I described the term and how it affects clinical studies in last week’s article. Here is a brief synopsis:

  • The studies supporting the HDL/heart health paradigm are association studies. Association studies measure the association between a single variable (in this case, increase in HDL levels) and an outcome (in this case, heart disease events, heart disease deaths, and total deaths).
  • Associations need to be corrected for other variables known to affect the same outcome (things like age, gender, smoking, and diabetes would be examples in this case).
  • Confounding variables are variables that also affect the outcome but are unknown or ignored. Thus, they are not used to correct the associations, which can bias the results.

The authors of this study (M Briel et al, BMJ 2009:338.b92) observed that most interventions that increase HDL levels also lower LDL levels. Lowering LDL is known to decrease the risk of heart disease deaths. But this effect had been ignored in most studies looking at the association between HDL and heart disease deaths.

They hypothesized that the change in LDL levels was a confounding variable that had been ignored in previous studies and may have biased the results.Heart Disease Study

To test this hypothesis the authors searched the literature and identified 108 studies with 299,310 participants that:

  • Compared the effect of drugs, omega-3 fatty acids, or diet with either a placebo or usual care.
  • Measured both HDL and LDL levels.
  • Measured reduction in cardiovascular risk.
  • Had a randomized control design.
  • Lasted at least 6 months.

They found that every 10 mg/dl decrease in LDL levels in these studies was responsible for a:

  • 7.1% reduction in heart disease events (both heart disease deaths and non-fatal heart attacks).
  • 7.2% reduction in heart disease deaths.
  • 4.4% reduction in total deaths.

After correcting for the effect of decreased LDL levels on these heart disease outcomes, the increase in HDL levels had no statistically significant effect on any of the outcomes.

The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”

In other words, this study:

  • Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.
  • Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.

Is Everything You Knew About HDL Wrong?

Peek Behind The CurtainDoes that mean that everything you knew about HDL is wrong? Not exactly. It just means that you need to change your perspective.

Don’t focus on HDL levels. Peek behind the curtain and focus on what’s behind the HDL levels. For example:

  • Losing weight when overweight increases HDL levels. But the decrease in heart disease outcomes is more likely due to weight loss than to the increase in HDL levels.
  • Exercise increases HDL levels. But the decrease in heart disease outcomes is more likely due to exercise than to the increase in HDL levels.
  • Reversing pre-diabetes or type 2 diabetes increases HDL levels. But the decrease in heart disease outcomes is more likely due to the reversal of diabetes than to the increase in HDL levels.
  • High-dose omega-3 fatty acids increase HDL levels. But the decrease in heart disease outcomes is more likely due to the omega-3 fatty acids than to the increase in HDL levels.
  • The Mediterranean diet increases HDL levels. But the decrease in heart disease outcomes is more likely due to the diet than to the increase in HDL levels.

And if you want to go the drug route:

  • Statins and some other heart drugs increase HDL levels, but the reduction in heart disease outcomes is probably due to their effect on LDL levels rather than their effect on HDL levels.

On the other hand:

  • Saturated fats increase HDL levels. But saturated fats increase heart disease risk and create pro-inflammatory HDL particles. So, in this case the increase in HDL levels is not a good omen for your heart.
  • Drugs have been discovered that selectively increase HDL levels. However, there is nothing of value behind this increase in HDL levels, so the drugs have no effect on heart disease outcomes.

The Bottom Line 

In this article I discuss several studies that have challenged the HDL/heart health paradigm – the belief that HDL is good for your heart.

For example, one group of investigators analyzed the studies underlying the HDL/heart health paradigm. They hypothesized that these studies were inaccurate because they failed to account for the effects of LDL levels on heart disease outcomes.

After correcting for the effect of decreased LDL levels on heart disease outcomes in the previous studies, the authors showed that increases in HDL levels had no significant effect on any heart disease outcome.

The authors concluded, “Available data suggest that simply increasing the amount of circulating HDL cholesterol does not reduce the risk of coronary heart disease events, coronary heart disease deaths, or total deaths. The results support reduction in LDL cholesterol as the primary goal for lipid modifying interventions.”

In other words, this study:

  • Supports the author’s hypothesis that LDL levels were a confounding variable that biased the studies supporting the HDL/heart health paradigm.
  • Concludes that increasing HDL levels has no effect on heart disease outcomes, thus invalidating the HDL/heart health paradigm.

Does that mean that everything you knew about HDL is wrong? Not exactly. It just means that you need to change your perspective. Don’t focus on HDL levels. Focus on what’s behind the HDL levels. For more information on that, read the article above.

For more information on this study, and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Are Low Carb Diets Healthier?

by

The “Goldilocks Effect”

Author: Dr. Stephen Chaney

Goldilocks EffectThe low-carb wars rage on. Low-carb enthusiasts claim that low-carb diets are healthy. Many health experts warn about the dangers of low-carb diets. Several studies have reported that low-carb diets increase risk of mortality (shorten lifespan).

However, two recent studies have come to the opposite conclusion. Those studies reported that high carbohydrate intake increased mortality, and low carbohydrate intake was associated with the lowest mortality.

One of those studies, called the Prospective Urban Rural Epidemiology (PURE) study was published a few years ago. It included data from 135,335 participants from 18 countries across 5 continents. That’s a very large study, and normally we expect very large studies to be accurate. The results from the PURE study had low-carb enthusiasts doing a victory lap and claiming it was time to rewrite nutritional guidelines to favor low-carb diets.

Whenever controversies like this arise, reputable scientists are motivated to take another look at the question. They understand that all studies have their weaknesses and biases. So, they look at previous studies very carefully and try to design a study that eliminates the weaknesses and biases of those studies. Their goal is to design a stronger study that reconciles the differences between the previous studies.

A third study published a year later (SB Seidelmann et al, The Lancet, doi.org/10.1016/S2468-2667(18)30135-X was such a study. This study resolved the conflicting data and finally answered the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. You may remember “Goldilocks And The Three Bears”. One bed was too hard. One bed was too soft. But one bed was “just right”. One bowl of porridge was too hot. One was two cold. But one was “just right”. According to this study, the same is true for carbohydrate intake. High carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But moderate carbohydrate intake is “just right”.

How Was The Study Done?

clinical studyThis study was performed in two parts. This first part drew on data from the Atherosclerosis Risk in Communities (ARIC) study. That study enrolled 15,428 men and women, aged 45-64, from four US communities between 1987 and 1989. This group was followed for an average of 25 years, during which time 6283 people died. Carbohydrate intake was calculated based on food frequency questionnaires administered when participants enrolled in the study and again 6 years later. The study evaluated the association between carbohydrate intake and mortality.

The second part was a meta-analysis that combined the data from the ARIC study with all major clinical studies since 2007 that measured carbohydrate intake and mortality and lasted 5 years or more. The total number of participants included in this meta-analysis was 432,179, and it included data from previous studies that claimed low-carbohydrate intake was associated with decreased mortality.

Are Low Carb Diets Healthier?

GravestoneThe results from the ARIC study were:

  • The relationship between mortality and carbohydrate intake was a U-shaped curve.
    • The lowest risk of death was observed with a moderate carbohydrate intake (50-55%). This is the intake recommended by current nutrition guidelines.
    • The highest risk of death was observed with a low carbohydrate intake (<40%).
    • The risk of death also increased with very high carbohydrate intake (>70%).
  • When the investigators used the mortality data to estimate life expectancy, they predicted a 50-year old participant would have a projected life expectancy of:
    • 33.1 years if they had a moderate intake of carbohydrates.
    • 4 years less if they had a low carbohydrate intake.
    • 1.1 year less if they had a very high carbohydrate intake.
  • The risk associated with low carbohydrate intake was affected by what the carbohydrate was replaced with.
    • When carbohydrates were replaced with animal protein and animal fat there was an increased risk of mortality on a low-carb diet. The animal-based low-carb diet contained more beef, pork, lamb, chicken, and fish. It was also higher in saturated fat.Beans and Nuts
    • When carbohydrates were replaced with plant protein and plant fats, there was a decreased risk of mortality on a low-carb diet. The plant-based low-carb diet contained more nuts, peanut butter, dark or whole grain breads, chocolate, and white bread. It was also higher in polyunsaturated fats.
  • The effect of carbohydrate intake on mortality was virtually the same for all-cause mortality, cardiovascular mortality, and non-cardiovascular mortality.
  • There was no significant effect of carbohydrate intake on long-term weight gain (another myth busted).

The results from the dueling meta-analyses were actually very similar. When the data from all studies were combined:

  • Both very low carbohydrate diets and very high carbohydrate diets were associated with increased mortality.
  • Meat-based low-carb diets increased mortality, and plant-based low-carb diets decreased mortality.
  • Once again, the results were the same for total mortality, cardiovascular mortality, and non-cardiovascular mortality.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

The “Goldilocks Effect”

low carb dietThis study also resolved the discrepancies between previous studies. The authors pointed out that the average carbohydrate intake is very different in Europe and the US than in Asian countries and low-income countries.

In the US and Europe mean carbohydrate intake is about 50% of calories and it ranges from 25% to 70% of calories. With that range of carbohydrate intake, it is possible to observe the increase in mortality associated with both very low and very high carbohydrate intakes.

The US and European countries are affluent, which means that low-carb enthusiasts can afford diets high in animal protein.

White rice is a staple in Asian countries, and protein is a garnish rather than a main course. Consequently, overall carbohydrate intake is greater in Asian countries and very few Asians eat a truly low carbohydrate diet. High protein foods tend to be more expensive than high carbohydrate foods. Thus, very few people in developing countries can afford to follow a very low carbohydrate diet, and overall carbohydrate intake also tends to be higher.

Therefore, in Asian and developing countries the average carbohydrate intake is greater (~61%) than in the US and Europe, and the range of carbohydrate intake is from 45% to 80% of calories. With that range of intake, it is only possible to see the increase in mortality associated with very high carbohydrate intake.

Both the studies that low-carb enthusiasts quote to support their claim that low-carb diets are healthy relied heavily on data from Asian and developing countries.ARIC Study

In fact, when the authors of the current study overlaid the data from the PURE study with their ARIC data, there was an almost perfect fit. The only difference was that their ARIC data covered both low and high carbohydrate intake while the PURE study touted by low-carb enthusiasts only covered moderate to high carbohydrate intake.

[I have given you my rendition of the graph on the right. If you would like to see the data yourself, look at the paper.]

Basically, low-carb advocates are telling you that diets with carbohydrate intakes of 30% or less are healthy based on studies that did not include carbohydrate intakes below 40%. That is misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

What Does This Study Mean For You?

QuestionsThere are several important take-home lessons from this study:

  • All major studies agree that very high carbohydrate intake is unhealthy. In part, that reflects the fact that diets with high carbohydrate intake are likely to be high in sodas and sugary junk foods. It may also reflect the fact that diets which are high in carbohydrate are often low in plant protein or healthy fats or both.
  • All studies that cover the full range of carbohydrate intake agree that very low carbohydrate intake is also unhealthy. It shortens the life expectancy of a 50-year-old by about 4 years.
  • The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.
  • Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with previous studies. For more details on those studies, see my article, “Are Any Low-Carb Diets Healthy?”, in “Health Tips From The Professor” or my book, “Slaying The Food Myths”.

The health risks of meat-based low-carb diets may be due to the saturated fat content or the heavy reliance on red meat. However, the risks are just as likely to be due to the foods these diets leave out – typically fruits, whole grains, legumes, and some vegetables.

Proponents of low-carb diets assume that you can make up for the missing nutrients by just taking multivitamins. However, each food group also provides a unique combination of phytonutrients and fibers. The fibers, in turn, influence your microbiome. Simply put, whenever you leave out whole food groups, you put your health at risk.

The Bottom Line

The low-carb wars are raging. Several studies have reported that low-carb diets increase risk of mortality (shorten lifespan). However, two studies published a few years ago have come to the opposite conclusion. Those studies have low-carb enthusiasts doing a victory lap and claiming it is time to rewrite nutritional guidelines to favor low-carb diets.

However, a study published a year later resolves the conflicting data and finally answers the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. According to this study, high carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But, moderate carbohydrate intake is “just right”.

Specifically, this study reported:

  1. Moderate carbohydrate intake (50-55%) is healthiest. This is also the carbohydrate intake recommended by current nutritional guidelines.

2) All major studies agree that very high carbohydrate intake (60-70%) is unhealthy. It shortens life expectancy of a 50-year old by about a year.

3) All studies that cover the full range of carbohydrate intake agree that low carbohydrate intake (<40%) is also unhealthy. It shortens life expectancy of a 50-year old by about 4 years.

4) The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

5) Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with the results of previous studies.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Which Supplements Are Good For Your Heart?

by

How Should You Interpret This Study? 

Author: Dr. Stephen Chaney 

strong heartFebruary is Heart Health month. So, it is fitting that we ask, “What is the status of heart health in this country?” The American Heart Association just published an update of heart health statistics through 2019 (CW Tsao et al, Circulation, 145: e153-e639, 2022). And the statistics aren’t encouraging. [Note: The American Heart Association only reported statistics through 2019 because the COVID-19 pandemic significantly skewed the statistics in 2020 and 2021].

The Good News is that between 2009 and 2019:

  • All heart disease deaths have decreased by 25%.
  • Heart attack deaths have decreased by 6.6%.
  • Stroke deaths have decreased by 6%.

The Bad News is that:

  • Heart disease is still the leading cause of death in this country.
  • Someone dies from a heart attack every 40 seconds.
  • Someone dies from a stroke every 3 minutes.

Diet, exercise, and weight control play a major role in reducing the risk of heart disease. Best of all, they have no side effects. They represent a risk-free approach that each of us can control.

But is there something else? Could supplements play a role? Are supplements hype or hope for a healthy heart?

All the Dr. Strangeloves in the nutrition space have their favorite heart health supplements. They claim their supplements will single-handedly abolish heart disease (and help you leap tall buildings in a single bound).

On the other hand, many doctors will tell you these supplements are a waste of money. They don’t work. They just drain your wallet.

It’s so confusing. Who should you believe? Fortunately, a recent study (P An et al, Journal of the American College of Cardiology, 80: 2269-2285, 2022) has separated the hype from the hope and tells us which “heart-healthy” supplements work, and which don’t.

How Was This Study Done?

Clinical StudyThis was a major clinical study carried out by researchers from the China Agricultural University and Brown University in the US. It was a meta-analysis, which means it combined the data from many published clinical trials.

The investigators searched three major databases of clinical trials to identify:

  • 884 randomized, placebo-controlled clinical studies…
  • Of 27 types of micronutrients…
  • With a total of 883,627 patients…
  • Looking at the effectiveness of micronutrient supplementation lasting an average of 3 years on either…
    • Cardiovascular risk factors like blood pressure, total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides…or…
    • Cardiovascular outcomes such as coronary heart disease (CHD), heart attacks, strokes, and deaths due to cardiovascular disease (CVD) and all causes.

[Note: Coronary heart disease (CHD) refers to build up of plaque in the coronary arteries (the arteries leading to the heart). It is often referred to as heart disease and can lead to heart attacks (myocardial infarction). Cardiovascular disease (CVD) is a more inclusive term that includes coronary heart disease, stroke, congenital heart defects, and peripheral artery disease.]

The investigators also included an analysis of the quality of the data in each of the clinical studies and rated the evidence of each of their findings as high quality, moderate quality, or low quality.

Which Supplements Are Good For Your Heart?

The top 3 heart-healthy supplements in this study were:

Omega-3s And Heart DiseaseOmega-3 Fatty Acids:

  • Increased HDL cholesterol and decreased triglycerides, both favorable risk factors for heart health.
  • Deceased risk of heart attacks by 15%, all CHD events by 14%, and CVD deaths by 7% (see definitions of CHD and CVD above).
  • The median dose of omega-3 fatty acids in these studies was 1.8 g/day.
  • The evidence was moderate quality for all these findings.

Folic Acid:

  • Decreased LDL cholesterol (moderate quality evidence) and decreased blood pressure and total cholesterol (low quality evidence).
  • Decreased stroke risk by 16% (moderate quality evidence).

Coenzyme Q10:

  • Decreased triglycerides (high quality evidence) and reduced blood pressure (low quality evidence).
  • Decreased the risk of all-cause mortality by 32% (moderate quality evidence).
  • These studies were performed with patients diagnosed with heart failure. Coenzyme Q10 is often recommended for these patients, so the studies were likely performed to test the efficacy of this treatment.

There were three micronutrients (vitamin C, vitamin E, and vitamin D) that did not appear to affect heart disease outcomes.

Finally, as reported in previous studies, β-carotene increased the risk of stroke, CVD mortality, and all-cause mortality.

In terms of the question I asked at the beginning of this article, this study concluded that:

  • Omega-3, folic acid, and coenzyme Q10 supplements represent hope for a healthy heart.
  • Vitamin C, vitamin E, and vitamin D supplements represent hype for a healthy heart.
  • β-carotene supplements represent danger for a healthy heart.

But these conclusions just scratch the surface. To put them into perspective we need to dig a bit deeper.

How Should You Interpret This Study?

Question MarkIn evaluating the significance of these findings there are two things to keep in mind.

#1: This study is a meta-analysis and meta-analyses have both strengths and weaknesses.

The strength of meta-analyses is that by combining multiple clinical studies they can end up with a database containing 100s of thousands of subjects. This allows them to do two things:

  • It allows the meta-analysis to detect statistically significant effects that might be too small to detect in an individual study.
  • It allows the meta-analysis to detect the average effect of all the clinical studies it includes.

The weakness of meta-analyses is that the design of individual studies included in the analysis varies greatly. The individual studies vary in things like dose, duration, type of subjects included in the study, and much more.

This is why this study rated most of their conclusions as backed by moderate- or low-quality evidence. [Note: The fact that the authors evaluated the quality of evidence is a strength of this study. Most meta-analyses just report their conclusions without telling you how strong the evidence behind those conclusions is.]

#2: Most clinical studies of supplements (including those included in this meta-analysis) have two significant weaknesses.

  • Most studies do not measure the nutritional status of their subjects prior to adding the supplement. If their nutritional status for a particular nutrient was already optimal, there is no reason to expect more of that nutrient to provide any benefit.
  • Most studies measure the effect of a supplement on a cross-section of the population without asking who would be most likely to benefit.

You would almost never design a clinical study that way if you were evaluating the effectiveness of a potential drug. So, why would you design clinical studies of supplements that way?

With these considerations in mind, let me provide some perspective on the conclusions of this study.

Coenzyme Q10:

This meta-analysis found that coenzyme Q10 significantly reduced all-cause mortality in patients with heart failure. This is consistent with multiple clinical studies and a recent Cochrane Collaboration review.

Does coenzyme Q10 have any heart health benefits for people without congestive heart failure? There is no direct evidence that it does, but let me offer an analogy with statin drugs.

Statin drugs are very effective at reducing heart attacks in high-risk patients. But they have no detectable effect on heart attacks in low-risk patients. However, this has not stopped the medical profession from recommending statins for millions of low-risk patients. The rationale is that if they are so clearly beneficial in high-risk patients, they are “probably” beneficial in low-risk patients.

I would argue a similar rationale should apply to supplements like coenzyme Q10.

Omega-3s:

This study found that omega-3 reduced both heart attacks and the risk of dying from heart disease. Most previous meta-analyses of omega-3s and heart disease have come to the same conclusion. However, some meta-analyses have failed to find any heart health benefits of omega-3s. Unfortunately, this has allowed both proponents and opponents of omega-3 use for heart health to quote studies supporting their viewpoint.

However, there is one meta-analysis that stands out from all the others. A group of 17 scientists from across the globe collaborated in developing a “best practices” experimental design protocol for assessing the effect of omega-3 supplementation on heart health. They conducted their clinical studies independently, and when their data (from 42,000 subjects) were pooled, the results showed that omega-3 supplementation decreased:

  • Premature death from all causes by 16%.
  • Premature death from heart disease by 19%.
  • Premature death from cancer by 15%.
  • Premature death from causes other than heart disease and cancer by 18%.

This study eliminates the limitations of previous meta-analyses. That makes it much stronger than the other meta-analyses. And these results are consistent with the current meta-analysis.

Omega-3s have long been recognized as essential nutrients. It is past time to set Daily Value (DV) recommendations for omega-3s. Based on the recommendations of other experts in the field, I think the DV should be set at 500-1,000 mg/day. I take more than that, but this would represent a good minimum recommendation for heart health.

folic acidFolic acid:

As with omega-3s, this meta-analysis reported a positive effect of folic acid on heart health. But many other studies have come up empty. Why is that?

It may be because, between food fortification and multivitamin use, many Americans already have sufficient blood levels of folic acid. For example, one study reported that 70% of the subjects in their study had optimal levels of folates in their blood. And that study also reported:

  • Subjects with adequate levels of folates in their blood received no additional benefit from folic acid supplementation.
  • However, for subjects with inadequate blood folate levels, folic acid supplementation decreased their risk of heart disease by ~15%.

We see this pattern over and over in supplement studies. Supplement opponents interpret these studies as showing that supplements are worthless. But a better interpretation is that supplements benefit those who need them.

The problem is that we don’t know our blood levels of essential nutrients. We don’t know which nutrients we need, and which we don’t. That’s why I like to think of supplements as “insurance” against the effects of an imperfect diet.

Vitamins E and D:

The situation with vitamins E and D is similar. This meta-analysis found no heart health benefit of either vitamin E or D. That is because the clinical studies included in the meta-analysis asked whether vitamin E or vitamin D improved heart health for everyone in the study.

Previous studies focusing on patients with low blood levels of these nutrients and/or at high risk of heart disease have shown some benefits of both vitamins at reducing heart disease risk.

So, for folic acid, vitamin E, and vitamin D (and possibly vitamin C) the take-home message should be:

  • Ignore all the Dr. Strangeloves telling you that these vitamins are “magic bullets” that will dramatically reduce your risk of heart disease.
  • Ignore the naysayers who tell you they are worthless.
  • Use supplementation wisely to make sure you have the recommended intake of these and other essential nutrients.

β-carotene:

This meta-analysis reported that β-carotene increased the risk of heart disease. This is not a new finding. Multiple previous studies have come to the same conclusion.

And we know why this is. There are many naturally occurring carotenoids, and they each have unique heart health benefits. A high dose β-carotene supplement interferes with the absorption of the other carotenoids. You are creating a deficiency of other heart-healthy carotenoids.

If you are not getting lots of colorful fruits and vegetables from your diet, my recommendation is to choose a supplement with all the naturally occurring carotenoids in balance – not a pure β-carotene supplement.

The Bottom Line 

The Dr. Strangeloves in the nutrition space all have their favorite heart health supplements. They claim their supplements will single-handedly abolish heart disease (and help you leap tall buildings in a single bound).

On the other hand, many doctors will tell you these supplements are a waste of money. They don’t work. They just drain your wallet.

It’s so confusing. Who should you believe? Fortunately, a recent study has separated the hype from the hope and tells us which “heart-healthy” supplements work, and which don’t.

This study was a meta-analysis of 884 clinical studies with 883,627 participants. It reported:

  • Omega-3 supplementation deceased risk of heart attacks by 15% and all cardiovascular deaths by 7%.
  • Folic acid supplementation decreased stroke risk by 16%.
  • Coenzyme Q10 supplementation decreased the risk of all-cause mortality in patients with heart failure by 32%.
  • Vitamin C, vitamin E, vitamin D did not appear to affect heart disease outcomes.
  • β-carotene increased the risk of stroke, CVD mortality, and all-cause mortality.

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Walking Your Way To Health

by

How Much Should You Walk? 

Author: Dr. Stephen Chaney 

Overweight People ExercisingThe new year is almost here. If you are like millions of Americans, you may already be making plans to join a gym, get a personal trainer, or join a spin class.

The problem is these are all expensive options. And a good portion of that money is wasted. To put it into perspective, let’s look at some statistics

  • Around 6 million Americans buy gym memberships every January.
  • 67% of those memberships are never used.
  • For those memberships used in January, another 50% are not in use 6 months later.
  • Americans spend about 1.6 billion dollars on unused gym memberships every year.
  • And that doesn’t include those gym memberships that are only occasionally used.

If you want to get fit and healthy in the new year, perhaps you should consider a less expensive option – like walking. Your only investments are a good pair of walking shoes and a device that keeps track of the number of steps you take (eg, Fitbit, smart watch, or smart phone).

You still may give up on your New Year’s goal of getting fitter at some point. But you won’t have wasted so much money.

Of course, you probably have some questions about the benefits of walking, such as:

  1. Is walking enough to significantly improve my fitness and health?

2) How far (how many steps) should I walk?

3) How fast should I walk?

Fortunately, two recent studies (B del Pozo-Cruz et al, JAMA Internal Medicine, 182: 1139-1148, 2022; J del Pozo-Cruz et al, Diabetes Care, 45: 2156-2158, 2022) have answered all three questions.

How Were These Studies Done?

clinical studyThe first study (B del Pozo-Cruz et al, JAMA Internal Medicine, 182: 1139-1148, 2022) followed 78,500 participants (average age 61, 55% female, 97% white) enrolled in the UK Biobank study for an average of 7 years.

At the time of enrollment, each participant was given an accelerometer (a device that measures the number and frequency of steps) to wear on their dominant wrist for 24 hours/day for 7 days. The investigators used the accelerometer data to categorize several types of physical activity.

  • Daily step counts (the average number of steps per day for 7 days). These step counts were further subdivided into two categories:
  • Incidental steps (It was assumed that ˂40 steps/min represented steps taken that were incidental to normal daily activities).
  • Purposeful steps (It was assumed that ≥40 steps/min represented steps taken as part of planned exercise).
  • Stepping intensity (the highest frequency of steps/min averaged over 30 min intervals for all 7 days).

At the end of the study, each of these variables was correlated with the risk of premature deaths due to all causes, cancer, and heart disease.

The second study (J del Pozo-Cruz et al, Diabetes Care, 45: 2156-2158, 2022) was similar except that it:

  • Used data from 1687 adults (average age = 55, 56% male, with diabetes or prediabetes when the study began) in the 2005-2006 National Health and Nutrition Examination Survey in the US.
  • Followed participants for 9 years instead of 7.
  • Only measured total steps/day
  • Correlated total steps/day with premature death for participants who already had prediabetes or diabetes when they entered the study.

Walking Your Way To Health

Study 1 looked at the effect of walking on health outcomes in multiple ways.

woman walking dog#1: Increase in number of steps/day:

  • On average study participants took an average of 7200 steps per day, but this ranged from a low of 3,200 steps/day to a high of 12,200 steps/day.
  • Each increase of 2,000 steps/day was associated with a:
    • 8% decrease in all-cause mortality.
    • 11% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.
  • Overall, increasing from 3,200 steps/day to 10,000 steps/day decreased all-cause, cancer, and heart disease mortality by around 36%.
  • There was no minimum threshold to this beneficial effect of walking on the risk of premature death.
  • The benefits of walking appeared to plateau at 10,000 steps/day.

#2: Increase in number of incidental steps/day (steps taken that are incidental to normal daily activities):

  • On average study participants took 3240 incidental steps/day, but this ranged from a low of 2,100 steps/day to a high of 4,400 steps/day.
  • Each 10% increase in incremental steps/day was associated with a:
    • 6% decrease in all-cause mortality.
    • 6% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.

#3: Increase in number of purposeful steps/day (steps taken as part of planned exercise):

  • On average study participants took 4,600 purposeful steps/day, but this ranged from a low of 1,600 steps/day to a high of 8,600 steps/day.
  • Each 10% increase in purposeful steps/day was associated with a:
    • 7% decrease in all-cause mortality.
    • 8% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.

#4: Increase in speed of walking or cadence. The measurement they used was “peak-30 cadence” – the Walking Fasthighest average steps/min during a 30-minute interval within a day:

  • On average study participants had a “peak-30 cadence” of 76 steps/min, but this ranged from a low of 47 steps/min to a high of 109 steps/min.
  • Each 10% increase in “peak-30 cadence” was associated with a:
    • 8% decrease in all-cause mortality.
    • 9% decrease in cancer mortality.
    • 14% decrease in heart disease mortality.
  • The benefits of walking rapidly (increase in “peak-30 cadence”) were in addition to the benefits seen by increasing the number of steps per day.
  • Overall, increasing from a “peak-30 cadence” of 47 steps/min to 109 steps/min decreased all-cause, cancer, and heart disease mortality by an additional 34%.
  • There was no minimum threshold to this beneficial effect of increasing “peak-30 cadence” (the speed of walking) on the risk of premature death.
  • The benefits of increasing “peak-30 cadence” appeared to plateau at 100 steps/min.

#5 Effect of walking on the prevention of heart disease and cancer: The investigators measured this by strong heartlooking at the effect of walking on the “incidence” of heart disease and cancer (defined as new diagnoses of heart disease and cancer) during the study. They found.

  • Each 2,000-step increase in the total number of steps/day decreased the risk of developing heart disease and cancer by 4% during this 7-year study.
  • Each 10% increase in the number of purposeful steps/day decreased the risk of developing heart disease and cancer by 4% during this study.
  • Each 10% increase in “peak-30 cadence” decreased the risk of developing heart disease and cancer by 7% during this study.

The authors concluded, “The findings of this population-based…study of 78,500 individuals suggest that up to 10,000 steps/day may be associated with a lower risk of mortality and cancer and CVD incidence. Steps performed at a higher cadence may be associated with additional risk reduction, particularly for incident disease.”

Study 2 extended these findings to diabetes. They started with participants that had either prediabetes or diabetesdiabetes and followed them for 9 years. They found that:

  • Study participants with prediabetes ranged from a low of 3,800 steps/day to a high of 10,700 steps/day.
    • Prediabetic participants walking 10,700 steps/day were 25% less likely to die during the study than participants walking only 3,800 steps/day.
  • Study participants with diabetes ranged from a low of 2,500 steps/day to a high of 10,200 steps/day.
    • Diabetic participants walking 10,200 steps/day were also 25% less likely to die during the study than participants walking only 2,500 steps/day.
  • Even small increases in the number of steps per day decreased the risk of premature death for both prediabetic and diabetic participants.
  • Once again, 10,000 steps/day appeared to be the optimal dose to lower the risk of premature death for both diabetic and prediabetic patients.

The authors of this study concluded, “Accumulating more steps/day up to ~10,000 steps/day may lower the risk of all-cause mortality of adults with prediabetes and diabetes.”

How Much Should You Walk?

Walking CoupleThat was a lot of information. You are probably wondering what it means for you. Let’s start with the big picture:

  • Going from couch potato to 10,000 steps per day may reduce your risk of premature death due to all causes, cancer, and heart disease by 36% (24% if you are already prediabetic or diabetic).
  • Increasing the speed with which you walk from 47 steps/min to 109 steps/min sustained for 30 minutes may reduce your risk of premature death by an additional 34%.

In other words, simply walking more and walking faster can have a significant on your health. I am not recommending walking as your only form of exercise. I’m just saying not to consider it inferior to other forms of exercise.

  • There is no lower limit to the benefits of walking. Even small increases in the number of steps/day you take and the speed with which you walk may have a beneficial effect on your health.

In other words, you don’t need to speed walk 10,000 steps/day to reap a benefit from walking. Even small increases are beneficial. That’s good news for those of you who may not be able to speed walk long distances. It also means that if you are a couch potato, you don’t need to attempt 10,000 steps at high speed from day 1. You can work up to it gradually.

  • Incidental walking (walking that is incidental to your daily activities) is almost as beneficial as purposeful walking (walking as part of a planned exercise).

That’s good news for those of you who may not have time for long walks. It also means that advice like “park your car at the far end of the parking lot and walk” or “take the stairs rather than the elevator” can have a meaningful impact on your health.

  • The benefits of walking appear to max out at around 10,000 steps per day and a cadence of 100 steps/min sustained for 30 minutes.

That means once you get to those levels, it’s time to consider adding other kinds of exercise to your regimen. More and faster walking may offer little additional benefit.

Finally, in the words of the authors, “This information could be used to motivate the least active individuals to increase their steps and the more-active individuals to reach the 10,000-step target.”

The Bottom Line 

The new year is almost here. If you are like millions of Americans, you may already be making plans to join a gym, get a personal trainer, or join a spin class.

If you want to get fit and healthy in the new year, perhaps you should also consider a less expensive option – like walking.

Of course, you probably have some questions about the benefits of walking, such as:

1) Is walking enough to significantly improve my fitness and health?

2) How far (how many steps) should I walk?

3) How fast should I walk?

Fortunately, two recent studies have answered all three questions. They found:

  • Going from couch potato to 10,000 steps per day may reduce your risk of premature death due to all causes, cancer, and heart disease by 36% (24% if you are already prediabetic or diabetic).
  • Increasing the speed with which you walk from 47 steps/min to 109 steps/min sustained for 30 minutes may reduce your risk of premature death by an additional 34%.
  • There is no lower limit to the benefits of walking. Even small increases in the number of steps/day you take and the speed with which you walk may have a beneficial effect on your health.
  • Incidental walking (walking that is incidental to your daily activities) is almost as beneficial as purposeful walking (walking as part of a planned exercise).
  • The benefits of walking appear to max out at around 10,000 steps per day and a cadence of 100 steps/min sustained for 30 minutes.

In the words of the authors of these studies, “This information could be used to motivate the least active individuals to increase their steps and the more-active individuals to reach the 10,000-step target.”

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 

Does Magnesium Protect Your Heart?

by

Do You Need A Magnesium Supplement?

Author: Dr. Stephen Chaney 

Getting an adequate amount magnesium from our diet should not be a problem. Magnesium is found in a wide variety of foods with the best sources being legumes (beans), nuts, seeds, whole grains, green leafy vegetables, and dairy foods.

The problem is:

  • None of these foods contain enough magnesium by themselves to provide the RDA (420 mg/day for men and 320 mg/day for women) for magnesium. We need to consume a variety of these foods every day – something most Americans aren’t doing.
  • These foods are decent sources of magnesium only in their unprocessed form. And most Americans consume more highly processed foods than whole, unprocessed foods.
  • Two to three servings of dairy provide a decent amount of magnesium, but many Americans are cutting back on dairy. And plant-based dairy substitutes often provide much less magnesium than the dairy food they replace.
  • Finally, green leafy vegetables (iceberg lettuce doesn’t count) don’t make it into the American menu as often as they should.

As a result, recent studies find that at least 50% of Americans are not getting enough magnesium in their diet. In fact, the average magnesium intake in this country is 268 mg/day for men and 234 mg/day for women. And the figures are not very different in other developed countries.

Does it matter? Recent studies have shown that an adequate intake of dietary magnesium is associated with lower risks of cardiovascular diseases (CVD) and all-cause mortality. This may be because of the of role of magnesium in supporting heart muscle contraction, normal heart rhythm, and blood pressure regulation. Adequate magnesium intake is also associated with lower risk of type 2 diabetes.

But what if you have already had a heart attack? Is it too late for magnesium to make a difference? A recent study (I Evers et al, Frontiers in Cardiovascular Medicine, August 12, 2022) was designed to answer this question.

The authors examined the effect of magnesium intake on cardiovascular disease (CVD) mortality, all-cause mortality, and coronary heart disease (CHD) mortality in patients who had experienced a recent heart attack.

[Note: CHD is defined as heart disease due to clogged coronary arteries, such as a heart attack. CVD includes CHD plus diseases caused by other clogged blood vessels, such as strokes and peripheral artery disease].

How Was The Study Done?

clinical studyThe authors used data from a previous study that had enrolled 4,365 Dutch patients aged 60-80 (average age = 69) who had experienced a heart attack within approximately 4 years prior to enrollment and followed them for an average of 12.4 years. All patients were receiving standard post-heart attack drug therapy.

The characteristics of the patients enrolled in the study were as follows:

  • Male 79%, female 21%
  • Average magnesium intake = 302 mg/day
  • Percent magnesium deficient: 72% of men and 67% of women
  • Percent taking magnesium supplements = 5.4%
  • Percent on drugs to lower blood pressure = 90%
  • Percent on statins = 86%
  • Percent on diuretics = 24%

Upon entry into the study the patients were asked to fill out a 203-item food frequency questionnaire reflecting their dietary intake over the past month. Trained dietitians reviewed the questionnaires and phoned the participants to clarify any unclear or missing items. The questionnaires were linked to the 2006 Dutch Food Composition Database to calculate magnesium intake and other aspects of their diets.

The patients were divided into 3 groups based on their energy adjusted magnesium intakes and those in the highest third (>322 mg/day) were compared to those in the lowest third (<238 mg/day) with respect to cardiovascular disease (CVD), all-cause mortality, and coronary heart disease (CHD) mortality.

The comparisons were statically adjusted for fiber intake (most magnesium-rich foods are also high fiber foods), diuretic use (diuretics reduce magnesium levels in the blood), age, sex, smoking, alcohol use, physical activity, obesity, education level, caloric intake, calcium, vitamin D, sodium from foods, potassium, heme iron, vitamin C, beta-carotenoids, polyunsaturated fatty acids, saturated fatty acids, overall diet quality based on the Dutch Dietary Guidelines, systolic blood pressure, kidney function, and diabetes. In other words, the data were adjusted for every conceivable variable that could have influenced the outcome.

Does Magnesium Protect Your Heart?

When those with the highest magnesium intake (>322 mg/day) were compared to those with the lowest intake (<283 mg/day):

  • Cardiovascular disease (CVD) mortality was reduced by 28%.
  • All-cause mortality was reduced by 22%.
  • Coronary heart disease (CHD) mortality was reduced by 16%, but that reduction was not statistically significant.

They then looked at the effect of some variables that might affect CVD risk on the results.

  • Diabetes, kidney function, iron intake, smoking, alcohol use, blood pressure, most dietary components and overall diet quality had no effect on the results.
  • The results were also not affected when patients using a magnesium supplement were excluded from the analysis. This suggests the effect of magnesium from diet and supplementation is similar.
  • However, diuretic use had a significant effect on the results.
    • For patients using diuretics, high magnesium intake versus low magnesium intake reduced CVD mortality by 45%.

How Much Magnesium Do You Need?

Question MarkYou may have noticed that the difference between the highest magnesium intake group and the lowest intake group was, on average, only 39 mg/day. So, the authors also used a statistical approach that utilized data from each individual patient to produce a graph of magnesium intake versus risk of CVD, total, and CHD mortality. For all 3 end points the graphs showed an inverse, linear relationship between magnesium and mortality.

From this, the authors were able to calculate the effect of each 100mg/day increase in magnesium intake on mortality risk. Each 100mg/day of added magnesium reduced the risk of:

  • CVD mortality by 38%.
  • All-cause mortality by 30%.
  • CHD mortality by 33%, and these results were borderline significant.

The inverse relationship between magnesium intake was observed at intakes ranging from around 200 mg/day to around 450 mg/day, which represented the range of dietary magnesium intake in this Dutch population group.

This study did not define an upper limit to the beneficial effect of magnesium intake because the graphs had not plateaued at 450 mg/day, suggesting that higher magnesium intakes might give even better results.

The authors concluded, “We observed a strong, linear inverse association of dietary magnesium with CVD and all-cause mortality after a heart attack, which was most pronounced in patients who used diuretics. Our findings emphasize the importance of an adequate magnesium intake in CVD patients, on top of cardiovascular drug treatment.”

I might add that this is the first study to look at the effect of magnesium on long-term survival after a heart attack.

Do You Need A Magnesium Supplement? 

magnesium supplements benefitsAs I said earlier, the best dietary sources of magnesium are beans, nuts, seeds, whole grains, green leafy vegetables, and dairy foods. And:

  • None of these foods contain enough magnesium by themselves to provide the RDA (420 mg/day for men and 320 mg/day for women) for magnesium.
  • These foods are decent sources of magnesium only in their unprocessed form.

When unprocessed, each of these foods provides 20 to 60 mg of magnesium per serving. If we use an average value of 40 mg/serving, you would need in the range of 8-10 servings/day of these foods in their unprocessed form to meet the RDA for magnesium.

You could get a more accurate estimate of the magnesium content of your diet using the “Magnesium Content of Selected Foods” table from the NIH Factsheet on Magnesium.

Now you are ready to ask yourself two questions:

  1. Does my current diet provide the RDA for magnesium?

2. If not, am I willing to make the dietary changes needed to increase my magnesium levels to RDA levels?

If your answer to both questions is no, you should probably consider a magnesium supplement. A supplement providing around 200 mg of magnesium should bring all but the worst diets up to the recommended magnesium intake.

The current study did not define an upper limit for the beneficial effect of magnesium on survival after a heart attack but suggested that intakes above 450 mg/day might be optimal.

I do not recommend megadoses of magnesium, but intakes from diet and supplementation that slightly exceed the RDA appear to be safe. In their Magnesium Factsheet, the NIH states, “Too much magnesium…does not pose a health risk in healthy individuals because the kidneys eliminate excess amounts in the urine.”

The only concern is that magnesium from supplements is absorbed much more rapidly than magnesium from foods, and this can cause gas, bloating, and diarrhea in some individuals. For this reason, I recommend a sustained release magnesium supplement, so the magnesium is absorbed more slowly.

Finally, we should not consider magnesium as a magic bullet. The current study statistically eliminated every known variable that might affect survival after a heart attack, so it could estimate the beneficial effects of magnesium alone.

However, survival after a heart attack will likely be much greater if diet, exercise, and body mass are also optimized.

The Bottom Line 

Recent studies have shown that an adequate intake of dietary magnesium is associated with lower risks of cardiovascular diseases (CVD) and all-cause mortality.

But what if you have already had a heart attack? Is it too late for magnesium to make a difference? A recent study of heart attack patients in Holland was designed to answer this question.

The authors examined the effect of magnesium intake on cardiovascular disease (CVD) mortality, all-cause mortality, and coronary heart disease (CHD) mortality in patients who had experienced a recent heart attack.

When heart attack patients with the highest magnesium intake (>322 mg/day) were compared to those with the lowest intake (<283 mg/day):

  • Cardiovascular disease (CVD) mortality was reduced by 28%.
  • All-cause mortality was reduced by 22%.
  • Coronary heart disease (CHD) mortality was reduced by 16%, but that reduction was not statistically significant.

The authors went on to look at the inverse linear relationship between magnesium intake and mortality risk. They found that each 100mg/day of added magnesium reduced the risk of:

  • CVD mortality by 38%.
  • All-cause mortality by 30%.
  • CHD mortality by 33%, and these results were borderline significant.

The authors concluded, “We observed a strong, linear inverse association of dietary magnesium with CVD and all-cause mortality after a heart attack…Our findings emphasize the importance of an adequate magnesium intake in CVD patients…”

I might add that this is the first study to look at the effect of magnesium on long-term survival of patients who have suffered a heart attack.

For more details on this study and my discussion of whether you might benefit from a magnesium supplement, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Health Tips From The Professor