coronary heart disease Archives - Health Tips From The Professor

Are All Carbs Bad?

August 1, 2023 by Dr. Steve Chaney

Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

Author: Dr. Stephen Chaney

Low carb enthusiasts have been on the warpath against carbohydrates for years.

Almost everyone agrees that sugar-sweetened sodas and highly processed, refined foods with added sugar are bad for us. But low carb enthusiasts claim that we should also avoid fruits, grains, and starchy vegetables. Have they gone too far?

Several recent studies suggest they have. For example, both association studies and randomized controlled studies suggest that total carbohydrate intake is neither harmful nor beneficial for heart health.

In addition, recent studies suggest that free sugar intake is associated with both elevated triglyceride levels and an increase in heart disease risk.

But those studies have mostly looked at free sugar intake from sugar-sweetened sodas. The authors of this study (RK Kelley et al, BMC Medicine, 21:34, 2023) decided to look more carefully at the effect of all free sugars and other types of carbohydrates on triglyceride levels and heart disease risk.

How Was This Study Done?

The 110,497 people chosen for this study were a subgroup of participants in the UK Biobank Study, a large, long-term study looking at the contributions of genetic predisposition and environmental exposure (including diet) to the development of disease in England, Scotland, and Wales.

The participants in this study were aged between 37 and 73 (average age = 56) on enrollment and were followed for an average of 9.4 years. None of them had a history of heart disease or diabetes or were taking diabetic medications at the time of enrollment.

During the 9.4-year follow-up, five 24-hour dietary recalls were performed, so that usual dietary intake could be measured rather than dietary intake at a single time point. The people in this study participated in an average of 2.9 diet surveys, and none of them had less than two diet surveys.

The averaged data from the dietary recalls were analyzed for the amount and kinds of carbohydrate in the diet. With respect to the types of carbohydrate, the following definitions would be useful.

The term free sugars includes all monosaccharides and disaccharides added to foods by the manufacturer, cook, or consumer, plus sugars naturally present in honey, syrups, and unsweetened fruit juices.

The term non-free sugars includes all sugars not in the free sugar category, mostly sugars naturally occurring in fruits, vegetables, and dairy products.

The term refined grains includes white bread, white pasta, white rice, most crackers and cereals, pizza, and grain dishes with added fat.

The term whole grains includes wholegrain bread, wholegrain pasta, brown rice, bran cereal, wholegrain cereals, oat cereal, and muesli.

Finally, the study looked at the association of total carbohydrate and each class of carbohydrate defined above with all heart disease, heart attacks, stroke, and triglyceride levels.

Are All Carbs Bad?

The study looked at total carbohydrate intake, free sugar intake, and fiber intake. In each case, the study divided the participants into quartiles and compared those in the highest quartile with those in the lowest quartile.

Using this criterion:

Total carbohydrate intake was not associated with any cardiovascular outcome measured (total heart disease risk, heart attack risk, and stroke risk).

Free sugar intake was positively associated with all cardiovascular outcomes measured. Each 5% increase in caloric intake from free sugars was associated with a:

- 7% increase in total heart disease risk.

- 6% increase in heart attack risk.

- 10% increase in stroke risk.

- 3% increase in triglyceride levels.

Fiber intake was inversely associated with total heart disease risk. Specifically, each 5 gram/day increase in fiber was associated with a:

- 4% decrease in total heart disease risk.

The investigators also looked at the effect of replacing less healthy carbohydrates with healthier carbohydrates. They found that:

Replacing 5% of caloric intake from refined grains with whole grains reduced both total heart disease risk and stroke risk by 6%.

Replacing 5% of caloric intake from free sugars (mostly sugar-sweetened beverages, fruit juices, and processed foods with added sugar) with non-free sugars (mostly fruits, vegetables, and dairy products) reduced total heart disease risk by 5% and stroke risk by 9%.

Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

With these data in mind let’s look at the claims of the low-carb enthusiasts.

Claim #1: Carbohydrates raise triglyceride levels. This study shows:

This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake (fruits, vegetables, and whole grains. This study did not measure intake of beans, nuts, and seeds, but they would likely be in the same category).

However, this claim is true with respect to foods high in free sugars (sugar-sweetened beverages, fruit juices, and processed foods with added sugar).

Claim #2: Carbohydrates increase heart disease risk. This study shows:

That claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.

However, this claim is true with respect to foods high in free sugars.

Claim #3: Carbohydrates cause weight gain [Note: Low carb enthusiasts usually word it differently. Their claim is that eliminating carbohydrates will help you lose weight. But that claim doesn’t make sense unless you believed eating carbohydrates caused you to gain weight.] This study shows:

This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.

Once again, this claim is true with respect to foods high in free sugars.

The data with high fiber carbohydrates was particularly interesting. When the authors compared the group with the highest fiber intake to the group with the lowest fiber intake, the high-fiber group:

Consumed 33% more calories per day.

But had lower BMI and waste circumference (measures of obesity) than the low-carbohydrate group.

This suggests that you don’t need to starve yourself to lose weight. You just need to eat healthier foods.

And, in case you were wondering, the high fiber group ate:

5 more servings of fruits and vegetables and…

2 more servings of whole grain foods than the low fiber group.

This is consistent with several previous studies showing that diets containing a lot of fruits, vegetables, and whole grains are associated with a healthier weight.

The authors concluded, “Higher free sugar intake was associated with higher cardiovascular disease incidence and higher triglyceride concentrations…Higher fiber intake and replacement of refined grain starch and free sugars with wholegrain starch and non-free sugars, respectively, may be protective for incident heart disease.”

In short, with respect to heart disease, the type, not the amount of dietary carbohydrate is the important risk factor.

What Does This Mean For You?

Forget the low carb “mumbo jumbo”.

Carbohydrates aren’t the problem. The wrong kind of carbohydrates are the problem. Fruit juice, sugar-sweetened sodas, and processed foods with added sugar:

- Increase triglyceride levels.

- Are associated with weight gain.

- Increase the risk for heart disease.

In other words, they are the villains. They are responsible for the bad effects that low carb enthusiasts ascribe to all carbohydrates.

Don’t fear whole fruits, vegetables, dairy, and whole grain foods. They are the good guys.

- They have minimal effect on triglyceride levels.

- They are associated with healthier weight.

- They are associated with a lower risk of heart disease and diabetes.

So, the bottom line for you is simple. Not all carbs are created equal.

Your mother was right. Eat your fruits, vegetables, and whole grains.

Avoid fruit juice, sodas and other sugar-sweetened beverages, and processed foods with added sugar. [Note: Artificially sweetened beverages are no better than sugar-sweetened beverages, but that’s another story for another day.]

And, if you were wondering why low carb diets appear to work for weight loss, it’s because any restrictive diet works short term. As I have noted previously, keto and vegan diets work equally well for short-term weight loss.

The Bottom Line

Low carb enthusiasts have been telling us for years to avoid all carbohydrates (including fruits, starchy vegetables, and whole grains) because carbohydrates:

Increase triglyceride levels.

Cause weight gain.

Increase our risk for heart disease.

A recent study has shown that these claims are only true for some carbohydrates, namely fruit juices, sodas and other sugar-sweetened beverages, and processed foods with added sugar.

Whole fruits, vegetables, and whole grain foods have the opposite effect. They:

Have a minimal effect on triglyceride levels.

Are associated with a healthier weight.

Are associated with a lower risk of heart disease and diabetes.

So, forget the low carb “mumbo jumbo” and be sure to eat your fruits, vegetables, and whole grains.

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

Is HDL Good For Your Heart?

June 13, 2023 by Dr. Steve Chaney

Is Everything You Knew About HDL Wrong?

Author: Dr. Stephen Chaney

In 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?

Once 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.

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?

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. 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.

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.

____________________________________________________________________________

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

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

Which Supplements Are Good For Your Heart?

February 7, 2023 by Dr. Steve Chaney

How Should You Interpret This Study?

Author: Dr. Stephen Chaney

February 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?

This 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-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?

In 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 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.

Does Magnesium Protect Your Heart?

October 25, 2022 by Dr. Steve Chaney

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?

The 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?

You 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?

As 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:

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.

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.