heart disease

Do Omega-3s Add Years To Your Life?

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Why Are Omega-3s So Controversial? 

Author: Dr. Stephen Chaney

ArgumentI don’t need to tell you that omega-3s are controversial. Some experts confidently tell you that omega-3s significantly reduce your risk of heart disease and may reduce your risk of cancer and other diseases. Other experts confidently tell you that omega-3s have no effect on heart disease or any other disease. They claim that omega-3 supplements are no better than “snake oil”.

The problem is that each camp of experts can cite published clinical studies to support their claims. How can that be? How can clinical studies come to opposite conclusions on such an important topic? The problem is that it is really difficult to do high quality clinical studies on omega-3s. I will discuss that in the next section.

The question of whether omega-3s affect life span has also been controversial. Heart disease and cancer are the top two causes of death in this country. So, if omega-3s actually reduced the risk of heart disease and cancer, you might expect that they would also help us live longer. Once again, there are studies on both sides of this issue, but they are poor quality studies.

We need more high-quality studies to clear up the controversies surrounding the health benefits of omega-3s. I will report on one such study in this issue of “Health Tips From The Professor”. But first let me go into more depth about why it is so difficult to do high-quality studies with omega-3 fatty acids.

Clinical Studies 101: Why Are Omega-3s So Controversial?

professor owlI have covered this topic in previous issues of “Health Tips From the Professor”, but here is a quick summary.

  1. Randomized, placebo controlled clinical trials (RCTs) are considered the gold standard for evidence-based medicine, but they ill-suited to measure the effect of omega-3s on health outcomes.
    • Heart disease and cancer take decades to develop. Most RCTs are too small and too short to show a meaningful effect of omega-3s on these diseases.
    • To make up for this shortcoming, some recent RCTs have started with older, sicker patients. This way enough patients die during the study that it can measure statistically significant outcomes. However, these patients are already on multiple medications that mimic many of the beneficial effects of omega-3s on heart disease.

These studies are no longer asking whether omega-3s reduce the risk of heart disease. They are really asking if omega-3s have any additional benefits for patients who are already taking multiple medications – with all their side effects. I don’t know about you, but that is not the question I am interested in.

    • Until recently, most RCTs did not measure circulating omega-3 levels before and after supplementation, so the investigators had no idea whether omega-3 supplementation increased circulating omega-3 levels by a significant amount.

And for the few studies where omega-3 levels were measured before and after supplementation, it turns out that for many of the participants, their baseline omega-3 levels were too high for omega-3 supplementation to have a meaningful effect. Only participants with low omega-3 levels at the beginning of the study benefited from omega-3 supplementation.Supplementation Perspective

These studies are often quoted as showing omega-3 supplementation doesn’t work. However, they are actually showing the true value of supplementation. Omega-3 supplementation isn’t for everyone. It is for people with poor diet, increased need, genetic predisposition, and/or pre-existing disease not already treated with multiple medications.

2) Prospective cohort studies eliminate many of the shortcomings of RCTs. They can start with a large group of individuals (a cohort) and follow them for many years to see how many of them die or develop a disease during that time (this is the prospective part of a prospective cohort trial). This means they can start with a healthy population that is not on medications.

This also means that these studies can answer the question on most people’s minds, “Are omega-3s associated with reduced risk of dying or developing heart disease?” However, these studies have two limitations.

    • They are association studies. They cannot measure cause and effect.
    • Ideally, omega-3 levels would be measured at the beginning of the study and at several intervals during the study to see if the participant’s diet had changed during the study. Unfortunately, most prospective cohort studies only measure omega-3 levels at the beginning of the study.

3) Finally, a meta-analysis combines data from multiple clinical studies.

    • The strength of a meta-analysis is that the number of participants is quite large. This increases the statistical power and allows it to accurately assess small effects.
    • The greatest weakness of meta-analyses is that the design of the individual studies included in the meta-analysis is often quite different. This introduces variations that decrease the reliability of the meta-analysis. It becomes a situation of “Garbage in. Garbage out”

The study (WS Harris et al, Nature Communications, Volume 12, Article number: 2329, 2021) I am discussing today is a meta-analysis of prospective cohort studies. It was designed to determine the association between blood omega-3 fatty acids and the risk of:

  • Death from all causes.
  • Death from heart disease.
  • Death from cancer.
  • Death from causes other than heart disease or cancer.

More importantly, it eliminated the major weakness of previous meta-analyses by only including studies with a similar design.

How Was This Study Done?

Clinical StudyThis study was a meta-analysis of 17 prospective cohort studies with a total of 42,466 individuals looking at the association between omega-3 fatty acid levels in the blood and premature death due to all causes, heart disease, cancer, and causes other than heart disease and cancer.

Participants in the 17 studies were followed for an average of 16 years, during which time 15,720 deaths occurred. This was a large enough number of deaths so that a very precise statistical analysis of the data could be performed.

The average age of participants at entry into the studies was 65, and 55% of the participants were women. Whites constituted 87% of the participants, so the results may not be applicable to other ethnic groups. None of the participants had heart disease or cancer when they entered the study.

Finally, the associations were corrected for a long list of variables that could have influenced the outcome (Read the publication for more details).

A strength of this meta-analysis is that all 17 studies were conducted as part of the FORCE (Fatty Acids & Outcomes Research Consortium) collaboration. The FORCE collaboration was established with the goal of understanding the relationships between fatty acids (as measured by blood levels of the omega-3 fatty acids) on premature death and chronic disease outcomes (cardiovascular disease, cancer, and other conditions).

Each study was designed using a standardized protocol, so that the data could be easily pooled for a meta-analysis. In the words of the FORCE collaboration founders:

  1. The larger sample sizes of [meta-analyses] will substantially increase statistical power to investigate associations…enabling the [meta-analyses] to discover important relationships not discernible in any individual study.

2) Standardization of variable definitions and modeling of associations will reduce variation and potential bias in estimates across cohorts.

3) Results will be far less susceptible to publication bias.

Do Omega-3s Add Years To Your Life?

Omega-3sThe meta-analysis divided participants into quintiles based on blood omega-3 levels. When comparing participants with the highest omega-3 levels with participants with the lowest omega-3 levels:

  • Premature death from all causes was decreased by 16%.
    • When looking at the effect of individual omega-3s, EPA > EPA+DHA > DHA.
  • Premature death from heart disease was decreased by 19%.
    • When looking at the effect of individual omega-3s, DHA > EPA+DHA > EPA.
  • Premature death from cancer was decreased by 15%.
    • When looking at the effect of individual omega-3s, EPA > DHA > EPA+DHA.
  • Premature death from causes other than heart disease and cancer was decreased by 18%.
    • When looking at the effect of individual omega-3s, EPA > EPA+DHA > DHA.
  • The differences between the effects of EPA, DHA, and EPA+DHA were small.
  • ALA, a short chain omega-3 found in plant foods, had no effect on any of these parameters.

In the words of the authors: “These findings suggest that higher circulating levels of long chain omega-3 fatty acids are associated with a lower risk of premature death. Similar relationships were seen for death from heart disease, cancer, and causes other than heart disease and cancer. No associations were seen with the short chain omega-3, ALA [which is found in plant foods]”.

What Does This Study Mean For You?

confusionIf you are thinking that 15-19% decreases in premature death from various causes don’t sound like much, let me do some simple calculations for you. The average lifespan in this country is 78 years.

  • A 16% decrease in death from all causes amounts to an extra 12.5 years. What would you do with an extra 12.5 years?
  • A 19% decrease in death from heart disease might not only allow you to live longer, but it has the potential to improve your quality of life by living an extra 15 years free of heart disease.
  • Similarly, a 15% decrease in death from cancer might help you live an extra 12 years cancer-free.
  • In other words, you may live longer, and you may also live healthier longer, sometimes referred to as “healthspan”.

Don’t misunderstand me. Omega-3s are not a magic wand. They aren’t the fictional “Fountain of Youth”.

  • There are many other factors that go into a healthy lifestyle. If you sit on your couch all day eating Big Macs and drinking beer, you may be adding the +12.5 years to a baseline of -30 years.
  • Clinical studies report average values and none of us are average. Omega-3s will help some people more than others.

I will understand if you are skeptical. It seems like every time one study comes along and tells you that omega-3s are beneficial, another study comes along and tells you they are worthless.

This was an extraordinarily well-designed study, but it is unlikely to be the final word in the omega-3 controversy. There are too many poor-quality studies published each year. Until everyone in the field agrees to some common standards like those in the FORCE collaboration, the omega-3 controversy will continue.

The Bottom Line 

A recent meta-analysis looked at the association between omega-3 fatty acid levels in the blood and premature death due to all causes, heart disease, cancer, and causes other than heart disease and cancer.

The meta-analysis divided participants into quintiles based on blood omega-3 levels. When comparing participants with the highest omega-3 levels with participants with the lowest omega-3 levels:

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

In the words of the authors: “These findings suggest that higher circulating levels of long chain omega-3 fatty acids are associated with a lower risk of premature death. Similar relationships were seen for death from heart disease, cancer, and causes other than heart disease and cancer.”

For more details about study and what this study 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.

 

 

Do Diet Sodas Hurt Your Heart?

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Love Your Heart

Author: Dr. Stephen Chaney

confusionHeart healthy diets are confusing.

  • First, we were told that fats, especially saturated fats, were the problem. Then it was carbohydrates.
  • Then, we were told not all carbohydrates were equally bad for us. Sugars were the culprit.
  • Next, we were told not all sugars were bad for us. It was added sugars, especially the sugars added to sodas and other sugary drinks.
  • In fact, most of the clinical studies on the bad effects of sugar have been done with sugar-sweetened sodas.
  • If sugar-sweetened sodas are the problem, then surely diet sodas must be the answer.

Maybe not. In a previous issue of “Health Tips From The Professor” I summarized studies showing that consuming diet sodas was just as likely to be associated with obesity and diabetes as consuming sugar-sweetened sodas.

But what about heart health? Are diet sodas better for your heart than sugar-sweetened sodas? A recent study (E. Chazelas et al, Journal of the American College of Cardiology, 76: 2175-2180, 2020) suggests the answer is no.

How Was The Study Done?

Clinical StudyThis study is part of a much larger French study on the effect of diet on health outcomes called the NutriNet-Sante cohort. The NutriNet-Sante cohort study was started in 2009 and, as the name suggests, makes extensive use of online questionnaires. For example:

  • Participants are asked to fill out online questionnaires on physical activity, socioeconomic status, anthropometric data (height, weight, etc.), and major health events on a regular basis.
  • Every 6 months participants are asked to fill out 3 web-based 24-h dietary records (2 on weekdays and 1 on a weekend).
  • Major health events were validated based on their medical records and France’s national health insurance system (Yes, Big Brother is definitely watching in France).
  • Deaths were validated using France’s national mortality registry.

The study included a total of 104,760 participants with an average age of 42.9 and an average BMI of 23.7 (towards the upper end of the normal range) and followed them for 10 years. [Note: The average BMI for Americans at age 40 is 28.6, which is towards the upper end of the overweight category.]

The study compared consumption of diet drinks and sugary drinks with first-time cases of heart disease events (stroke, heart attack, angina, and angioplasty) during a 10-year period.

  • All first-time cases of heart disease events were combined into a single category for this publication. They will be considered separately in a subsequent publication.
  • Artificially sweetened beverages (diet drinks) were defined as beverages containing non-nutritive sweeteners. Sugary drinks consisted of all beverages containing ≥ 5% sugar (sodas, syrups, 100% juice, and fruit drinks).
  • For both categories of beverages, the participants were divided into non-consumers, low consumers, and high consumers.

Do Diet Sodas Hurt Your Heart?

Fast Food DangersThe results were clear. When high consumers were compared with non-consumers:

  • High consumers of sugary drinks had a 20% increased risk of first-time heart disease events.
  • High consumers of diet drinks had a 32% increased risk of first-time heart disease events.

The authors concluded, “In this cohort, higher intakes of [both] sugary drinks and diet drinks were associated with a higher risk of heart disease, suggesting that artificially sweetened beverages might not be a healthy substitute for sugary drinks.”

I also might point out that if this study had been done in the United States the increased risk of heart disease might have been greater.

That is because the French drink less sugary drinks and diet drinks than Americans.

  • High consumers of both sugary drinks and diet drinks in this study averaged 6 ounces per day.
  • In contrast, the average consumption sugary drinks in the United States is around 17 ounces per day.

Since consumption of sugary drinks is associated with increased incidence of heart disease and we drink more sugary drinks, the increased risk of heart disease in Americans might be greater than the 20% reported in this study.

What Are The Pros And Cons Of This Study?

pros and consOn the plus side, this was a very large and well-designed study.

For example, many studies of this type take a single assessment of the participant’s diet, either at the beginning or end of the study. They have no idea whether the participants changed their diet during the study. This study did a diet assessment every 6 months.

On the minus side, this was an association study. It measured the association of sugary drink and diet drink consumption with heart disease. Association studies have several limitations. Here are the top three:

#1: Confounding variables. Here are a couple of examples:

  • People who are overweight tend to drink more diet drinks than people who are normal weight. Obesity increases the risk of heart disease. Therefore, obesity is a confounding variable. You don’t know whether heart disease increased because the participants drank more diet drinks or because they were obese.
  • People who consume more diet drinks tend also to eat less healthy diets. Unhealthy diets increase the risk of heart disease. Thus, unhealthy diets are also a confounding variable.

The study authors adjusted for confounding variables by statistically correcting the data for:

  • Age, sex, BMI, sugar intake from other dietary sources, smoking status, physical activity, and family history of heart disease.
  • Intakes of alcohol, total calories, fruits & vegetables, red & processed meats, nuts, whole grains, legumes, saturated fat, sodium, and proportion of highly processed food in the diet.
  • Presence of type 2 diabetes, elevated cholesterol or triglycerides, or high blood pressure upon entry into the study.

In short, they did an excellent job of controlling for confounding variables that also affect the risk of heart disease.

#2: Reverse Causation: This is the chicken and egg question. This study measured the association between sugary and diet drink consumption and heart disease. None of the participants in the study had diagnosed heart disease when the 10-year study began.

However, both obesity and sugar consumption have been linked to increased risk of heart disease. What if some participants in the study had been diagnosed with heart disease early in the study and switched to diet drinks to lose weight or reduce sugar intake?

In that case, the diagnosis of heart disease would have caused increased diet drink consumption rather than the other way around. That would be reverse causation.

The study authors took reverse causation into account by excluding participants who experienced a first-time heart disease event in the first 3 years of this 10-year study. In other words, participants had to have been consuming sugary or diet drinks for at least 3 years before their heart disease event for their data to be included in the analysis.

This is considered the gold standard for reducing the influence of reverse causation on the outcome of the study.

#3: Uncertainty About Causation:

Association studies do not provide information on the possible mechanism(s) of the association.

For example, multiple previous studies have shown that people are just as likely to gain weight and develop type 2 diabetes when they consume diet drinks or sugary drinks. However, after years of study, the mechanism(s) of that effect are uncertain.

  • The mechanism may be physiological. However, many physiological mechanisms have been proposed. None have been proven.
  • The mechanism may be psychological. We may feel so virtuous for drinking diet drinks that we think it gives us license to eat more junk food. As a former University of North Carolina colleague once put it, “The problem is that we are using our diet drinks to wash down a Big Mac and fries.”

Association studies also do not prove causation. We cannot say with confidence that diet drink consumption increases our risk of heart disease. Nor can we speculate on the mechanism by which this might occur.

However, as the authors of this study concluded, we can say with confidence that there is no evidence that diet drink consumption decreases the risk of obesity, diabetes, or heart disease.

Love Your Heart

Love Your Heart – Drink Water Rather Than Sugar-Sweetened Or Artificially Sweetened Beverages. 

strong heartIf drinking diet drinks does not decrease your risk of heart disease, what can you do to decrease your risk?

The short answer is to fall in love with water. Water has no calories, no sugar, and no artificial sweeteners. In the study described above, it was the non-consumers of sugary beverages and diet beverages that had the lowest risk of heart disease.

Pure water is, of course, the best alternative. However, if plain water is too boring, try herbal teas. If you crave the fizz of sodas, try unsweetened sparkling water, perhaps infused with a little of your favorite fresh fruit. If you crave the caffeine of sodas, coffee or tea might suit you best, preferably without the sugar and cream. There are just two caveats:

  • Tea and coffee should not be your only source of liquid.
  • It goes without saying that you want to avoid the 500 calorie Starbucks extravaganzas.

Love Your Heart – What About Artificially Sweetened Foods?

If artificially sweetened drinks have no benefit for preventing obesity, diabetes, or heart disease, what about artificially sweetened foods? Do they also have no benefit?

The short answer is that we don’t know. Most of the studies to date have been with artificially sweetened beverages. However, these studies should make us cautious. We should not automatically assume that artificially sweetened foods are beneficial because they contain fewer calories. They may be just as useless as artificially sweetened beverages.

Love Your Heart – A Holistic Approach

With that in mind, here is what the American Heart Association recommends for reducing your risk of heart disease:

  • If you smoke, stop.
  • Choose good nutrition.
    • Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, nuts, and nontropical vegetable oils (ie, avoid coconut and palm oil).
    • Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.
    • [Note: Don’t substitute artificially sweetened beverages for sugar-sweetened beverages. That doesn’t appear to offer any advantage. Drink water instead.]
  • Reduce high blood cholesterol and triglycerides.
    • Reduce your intake of saturated fat, trans fat and cholesterol and get moving.
    • If diet and physical activity don’t get your cholesterol and triglyceride numbers under control, then medication may be the next step.
    • [Note: The American Heart Association recommends changing your diet and physical activity first and only resorting to medications if lifestyle changes don’t work. Diet and exercise do not have side effects. Medications do.]
  • Lower High Blood Pressure.
  • Be physically active every day.
  • Aim for at least 150 minutes per week of moderate-intensity physical activity per week.
  • Aim for a healthy weight.
  • Manage diabetes.
  • Reduce stress.
  • Limit alcohol.

The Bottom Line 

Previous studies have shown that people are just as likely to gain weight and develop type 2 diabetes when they consume artificially sweetened and sugar-sweetened drinks. In this issue of “Health Tips From the Professor” I shared a study showing that artificially sweetened drinks are just as bad for your heart as sugar-sweetened drinks.

These are all association studies. Association studies do not provide information on the possible mechanism(s) of the association.

That means we don’t know why artificially sweetened drinks are bad for your heart.

  • The mechanism may be physiological. However, many physiological mechanisms have been proposed. None have been proven.
  • The mechanism may be psychological. We may feel so virtuous for drinking diet drinks that we think it gives us license to eat more junk food. As a former UNC colleague once put it, “The problem is that we are using our diet drinks to wash down a Big Mac and fries.”

Association studies also do not prove causation. We cannot say with confidence that diet drink consumption increases our risk of heart disease. Nor can we speculate on the mechanism by which this might occur.

However, we can say with confidence that there is no evidence that diet drink consumption decreases the risk of obesity, diabetes, or heart disease.

The authors of this study concluded, “…higher intakes of [both] sugary drinks and diet drinks were associated with a higher risk of heart disease, suggesting that artificially sweetened beverages might not be a healthy substitute for sugary drinks.”

For more details on the study and information on a holistic approach for reducing heart disease risk 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.

 

Update On Omega-3 Supplementation And Heart Disease

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How Much Omega-3s Do You Need?

Pendulum
Pendulum

In previous issues of “Health Tips From The Professor” I have described the medical consensus about omega-3 supplementation and heart disease as resembling a pendulum.

A few positive studies are published, and the pendulum swings in the positive direction. The medical consensus becomes, “Omega-3s may reduce heart disease risk.”

Then a few negative studies are published, and the pendulum swings in the other direction. The consensus becomes that omega-3 supplements are worthless. One review a few years ago went so far as to say that fish oil supplements were the modern-day version of snake oil.

Meta-analyses combine the data from multiple clinical studies to increase statistic power and minimize the effect of clinical studies that are outliers. They are supposed to provide clear answers to medical questions like the effect of omega-3 supplements on heart disease.

However, the meta-analyses published to date have also reached conflicting conclusions about the effectiveness of omega-3 supplementation. No wonder you [and the medical community] are confused!

In 2018 three large, well-designed, clinical studies looking at the effect of omega-3 supplementation on heart disease risk were published. They reached different conclusions. However, they covered a much wider range of omega-3 doses than previous studies. And the studies with the highest doses of omega-3s showed the most positive effect of omega-3 supplementation on the reduction of heart disease risk.

That lead a group of doctors and scientists from the United States and Finland to postulate that many previous studies had failed to find an effect of omega-3 supplements on heart disease risk because the dose of omega-3s they used was too low.

These scientists designed a very large meta-analysis (AA Bernasconi et al, Mayo Clinic Proceedings, doi.org/10.1016/j.mayocp.2020.08.034) to test their hypothesis. In short, their study was designed to:

  • Determine whether supplementation with the omega-3 fatty acids EPA and DHA resulted in reduced heart disease risk.
  • Quantify the relationship between the dose of EPA + DHA and the risk of heart disease outcomes.

How Was The Study Done?

Clinical StudyThis study was a meta-analysis of 40 randomized control clinical studies on the effect omega-3 supplementation on heart disease outcomes. Specifically:

  • It included all high-quality clinical studies of omega-3 supplementation published before August 2019.
  • It included a total of 135,267 participants.
  • It included participants at both low and high risk of developing heart disease.
  • It included studies of supplementation with EPA alone and with EPA + DHA.
  • It included omega-3 doses ranging from 400 mg/day to 5,500 mg/day.
  • It excluded dietary studies because:
    • It is difficult to measure the dosage of omega-3s that participants are consuming in dietary studies.
    • It is difficult to assure their compliance with dietary advice.
    • There is variation in the omega-3 content of various foods.
    • Participants in these studies are often advised to make other changes in diet. It then becomes difficult to know whether any benefits observed were from changes in omega-3s or from changes in other components of the diet.

Update On Omega-3 Supplementation And Heart Disease

omega-3 supplements and heart healthHere are the results of the meta-analysis. Supplementation with EPA or EPA + DHA reduced:

  • Coronary Heart disease (defined as diseases caused by atherosclerosis, such as angina, heart attack, and heart failure) by 10%.
  • Heart Attacks by 13%.
  • Coronary Heart disease deaths by 9%.
  • Heart attack deaths by 35%.

Because of the large number of participants in this meta-analysis, they were able to reach some other important conclusions:

  • Despite the claims you may have heard about a new drug consisting of highly purified EPA, this study found no evidence that EPA supplementation was superior to EPA + DHA supplementation.
  • Even though heart medications provide some of the same benefits as omega-3s, this study concluded that omega-3 supplementation reduced the risk of heart disease even for patients on multiple heart medications.
  • This study also concluded that omega-3 supplementation was likely to be effective for people at both low and high risk of heart disease. This means that omega-3 supplementation is likely to be beneficial for preventing heart disease.

The authors concluded: “The current study provides strong evidence that EPA + DHA supplementation is an effective strategy for the prevention of certain coronary heart disease outcomes…Considering the relatively low costs and side effect profiles of omega-3 supplementation and the low drug-drug interactions with other standard therapies…clinicians and patients should consider the potential benefits of omega-3 (EPA/DHA) supplementation…”

What Does This Study Mean For You?

Heart AttackThe most significant conclusions from this study are the reduction in heart attacks and heart attack deaths. That is because:

  • Approximately 1.5 million Americans suffer a heart attack each year. For those who survive their quality of life may be permanently altered.
    • A 13% reduction in heart attacks means that something as simple as EPA + DHA supplementation might prevent as many as 195,000 heart attacks a year.
  • Approximately 100,000 Americans will die from a heart attack each you.
    • A 35% reduction in heart attack deaths means that EPA + DHA supplementation might prevent as many as 35,000 deaths from heart attacks each year.
  • For many Americans sudden death from a heart attack is the first indication that they have heart disease.
    • As Benjamin Franklin said, “An ounce of prevention is worth a pound of cure”. That is why EPA + DHA supplementation makes sense for most people.

I can’t say that this study will be the final word on omega-3 supplementation and heart disease risk. However, several recent studies have supported the benefit of omega-3 supplementation at reducing heart disease risk. The pendulum has clearly swung in the direction of omega-3s being beneficial for heart health.

Of course, omega-3 supplementation is not a magic “Get Out of Jail Free” card. You can’t expect it to overcome the effects of a bad diet and lack of exercise with omega-3 supplementation alone. You need a holistic approach.

The American Heart Association recommends:

Doctor With Patient

  • If you smoke, stop.
  • Choose good nutrition.
    • Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils, and nuts.
    • Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.
  • Reduce high blood cholesterol and triglycerides.
  • Reduce your intake of saturated fat, trans fat and cholesterol and get moving.
  • Lower High Blood Pressure.
  • Be physically active every day.
    • Aim for at least 150 minutes per week of moderate-intensity physical activity per week.
  • Aim for a healthy weight.
  • Manage diabetes.
  • Reduce stress.
  • Limit alcohol.
  • Have a regular physical checkup.

Add in omega-3 supplementation to these recommendations and you have a winning combination.

How Much Omega-3s Do You Need?

Question MarkAs I mentioned at the beginning of this article the omega-3 dosages used in the studies included in this meta-analysis ranged from 400 mg/day to 5,500 mg/day. More importantly, there were enough participants in these studies to obtain a fairly accurate estimate of dose response. This allow the authors to answer the question, “How much omega-3s do I need?”The study found that:

  • The protective effect of omega-3s for heart attack deaths and coronary heart disease deaths plateaued with dosages of EPA + DHA that exceeded 800 – 1200 mg/day.
  • The dose response of the protective effect of omega-3s for non-fatal heart attacks was linear over a wider range of dosages, with every increase 1,000 mg/day of EPA + DHA decreasing the risk of heart attack by 9%.

Based on the totality of their data, the authors concluded, “…clinicians and patients should consider the potential benefits of omega-3 supplementation, especially using 1,000 to 2,000 mg/day dosages, which are rarely obtained in most Westernized diets, even those including routine fish consumption.”

The Bottom Line

A recent meta-analysis combined the data from 40 clinical studies with over 135,000 participants looking at the effect of omega-3 supplementation on various types of heart disease. The study found that supplementation with EPA or EPA + DHA reduced:

  • Coronary Heart disease (defined as diseases caused by atherosclerosis, such as angina, heart attack, and heart failure) by 10%.
  • Heart Attacks by 13%.
  • Coronary Heart disease deaths by 9%.
  • Heart attack deaths by 35%.

Because of the large number of participants in this meta-analysis, they were able to reach some other important conclusions:

  • This study found no evidence that EPA supplementation was superior to EPA + DHA supplementation.
  • This study concluded that omega-3 supplementation reduced the risk of heart disease even for patients on multiple heart medications.
  • This study also concluded that omega-3 supplementation was likely to be effective for people at both low and high risk of heart disease. This means that omega-3 supplementation is likely to be beneficial for preventing heart disease.
  • The optimal dose of EPA + DHA appeared to be 1,000 – 2,000 mg/day.

The authors of the study concluded: “The current study provides strong evidence that EPA + DHA supplementation is an effective strategy for the prevention of certain coronary heart disease outcomes…Considering the relatively low costs and side effect profiles of omega-3 supplementation and the low drug-drug interactions with other standard therapies…clinicians and patients should consider the potential benefits of omega-3 (EPA/DHA) supplementation, especially using 1,000 to 2,000 mg/day dosages, which are rarely obtained in most Westernized diets, even those including routine fish consumption.”

For more details, including a more detailed discussion of what this study 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.

Do Processed Foods Increase Your Risk Of Diabetes?

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Why Do We Keep Eating Processed Foods?

Fast Food DangersUnless you are Rip Van Winkle and have been asleep for the past 20 years you probably know that the highly processed foods in the typical American diet are bad for your health. But perhaps you didn’t realize just how bad they were.

But first, let’s start with a bit of perspective. Scientists like to be precise. Even healthy foods go through some processing.

  • The oatmeal you ate this morning was either steel-cut or ground. That is processing.
  • The almond butter you put on your whole grain toast this morning was made by roasting and grinding. That is processing.

So, scientists have developed the term “ultra-processed food” to describe the worst of the worse. In short, ultra-processed foods:

  • Usually go through several physical and chemical processes, such as extruding, molding, prefrying, and hydrogenation that can lead to the formation of toxic contaminants. One example you may have heard about recently would be acrylamide in French fries.
  • Typically contain ingredients of no or little nutritive value, such as refined sugar, hydrogenated oils, emulsifiers, artificial sweeteners, thickening agents, and artificial colors. Some of these ingredients have been linked to cancer, heart disease, and premature death.
  • Have long shelf-lives because of added preservatives. This allows migration of chemicals such as bisphenol A from the packaging materials into the food.

Examples of ultra-processed foods include:

  • Sodas
  • Chips
  • Candy and packages of cookies or crackers
  • Most breakfast cereals
  • Boxed cake, cookie, and pancake mix
  • Chicken nuggets and fish sticks
  • Fast food burgers
  • Hot dogs and other processed meats
  • Infant formula
  • Instant noodles
  • Most store-bought ice cream
  • Flavored yogurt

In short, ultra-processed foods include sodas and the junk and convenience foods Americans hold so dear. Even things like infant formula and flavored yogurt make the list.

Evidence of the ill effects of ultra-processed foods on our health is becoming overwhelming. In previous issues of “Health Tips From the Professor” I have shared recent studies that have shown that heavy consumption of ultra-processed foods is linked to increased risk of obesity and cancer. Other studies have linked ultra-processed food consumption with increased risk of depression, heart disease, and premature death.

In this issue of “Health Tips From the Professor” I:

  • Ask the important question, “If we know these foods are so bad for us, why do we still keep eating them?”

How Was The Study Done?

Clinical StudyThe data from this study were taken from an ongoing study in France (the NutriNet-Sante study) looking at associations between nutrition and health. This study began enrolling French adults 18 and older in 2009.

This is a web-based study. Participants are prompted to go to a dedicated website and fill out questionnaires related to things like sex, age, height, weight, smoking status, physical activity, health status, and diet.

With respect to diet, participants filled out a series of 3 nonconsecutive 24-hour dietary records at the time of enrollment and every 6 months. This is a particularly strong feature of this study. Many studies of this type only analyze participant’s diets at the beginning of the study. Those studies have no way of knowing how the participant’s diets may have changed during the study.

Diagnosis of type 2 diabetes for study participants was obtained from the French centralized health records.

The study enrolled 104,708 participants, 20% men and 80% women, and followed them for an average of 6 years. The average age of the participants was 43 years.

Do Processed Foods Increase Your Risk Of Diabetes?

High Blood SugarIn this study the range of ultra-processed foods in the French diet ranged from 7% to 27% (average = 17%). High intake of ultra-processed foods was associated with:

  • Younger participants. Simply put, young people were more likely to drink sodas and eat junk food than older adults.
  • Increased caloric intake. Ultra-processed foods have a higher caloric density than whole, unprocessed foods.
  • No surprise here. Previous studies have shown that ultra-processed food consumption increases the risk of obesity.
  • Poorer diet quality. Again, no surprise. Junk foods tend to crowd healthier foods out of the dirt. Specifically, ultra-processed food consumption was associated with:
    • Higher intake of sugar and salt.
    • Lower intake of fiber.
    • Higher intake of sugary drinks, red and processed meats.
    • Lower intake of whole grains, yogurt, nuts, fruits, and vegetables.

However, even after statistically correcting for all these factors, there was a significant association between ultra-processed food consumption and the onset of type 2 diabetes in the 6-year follow-up period.

  • There was a linear relation between ultra-processed food consumption and the development of type 2 diabetes. Simply put, the more ultra-processed food the participants consumed the more likely they were to be diagnosed with type 2 diabetes.
  • There was a 15% increased risk of developing type 2 diabetes for every 10% increase in ultra-processed food consumption.

The authors concluded:

“In this large observational prospective study, a higher proportion of ultra-processed food in the diet was associated with a higher risk of type 2 diabetes. Even though these results need to be confirmed in other populations and settings, they provide evidence to support efforts by public health authorities to recommend limiting ultra-processed food consumption.”

What Does This Study Mean For You?

Questioning WomanYou might be tempted to say that a 15% increase in the risk of developing diabetes is a small price to pay for continuing to eat the foods you enjoy. However, you should be alarmed by this study. Here is why.

The French diet is much healthier than the American. Remember that ultra-processed foods only comprised 17% of the French Diet. In contrast, a recent survey found that:

  • Ultra-processed foods make up 58% of the average American’s diet.
  • Ultra-processed foods account for 90% of the added sugar in our diet.

It is no wonder that obesity and diabetes are reaching epidemic proportions in our country.

You might also be tempted to think that you can just take some medications and live with type 2 diabetes. However, you should think of type 2 diabetes as a gateway disease. It increases your risk of heart disease, high blood pressure, Alzheimer’s disease, kidney damage, and neuropathy, just to name a few. These are diseases that make your life miserable and ultimately kill you.

More importantly, type 2 diabetes is completely reversible if you catch it early enough. Just lose some weight, exercise more, give up the ultra-processed foods, and eat a healthy diet. I recommend a whole food, primarily plant-based diet.

Why Do We Keep Eating Processed Foods?

Fast FoodsWe all know that ultra-processed foods are bad for us. Study after study show that they make us sick. They kill us prematurely. And, unlike most topics in the field of nutrition, this is not controversial.

For example, there have been lots of bizarre diets that have come and gone over the years. There have been books written on “The Steak Lover’s Diet” and “The Drinking Man’s Diet”. But nobody has written a book on “The Junk Food Lover’s Diet”. It simply would not be believable.

So why do we Americans keep eating such unhealthy foods. Part of the answer is physiological. A preference for sweet, salty, and fatty foods is hardwired into our brain. That’s because they had great survival value in prehistoric times.

If we think back to the time when we were hunters and gatherers:

  • Fruits are healthy foods. They are a great source of antioxidants, phytonutrients, and fiber, but there were no orchards or grocery stores back then. We had to search for fruits in the wild. Our desire for sweet tasting foods provided the motivation to seek them out.
  • Game was seasonal and sometimes scarce. We had to be prepared to go for days or weeks without eating except for the leaves and roots we could gather. Our bodies are designed to store fat as the primary energy source to get us through the lean times. Our preference for fatty foods encouraged us to store as much fat as possible in times of plenty so we would be prepared for times of scarcity.
  • If we fast forward to our early recorded history, salt was scarce. It was worth its weight in gold. Yet some salt is essential for life. Our preference for salty foods encouraged us to search out supplies of salt.

Unfortunately, the food industry has weaponized these food preferences to create the ultra-processed foods we know today. Their ads entice us by associating these foods with youth and good times. And ultra-processed foods have become ubiquitous. There are fast food restaurants on almost every street corner and shopping mall in the country.

Fortunately, we do not have to let the food industry destroy our health. We can retrain our taste buds to appreciate the sweetness of fresh fruits and vegetables. We can substitute healthy fats for the kinds of fat found in most ultra-processed foods. We can also retrain our taste buds to appreciate herbs and spices with just a pinch of salt.

The Bottom Line

Ultra-processed foods, such as sodas, junk foods, and convenience foods have become the biggest food group in the American diet. A recent study found:

  • Ultra-processed foods make up 58% of the average American’s diet.
  • Ultra-processed foods account for 90% of the added sugar in our diet.

That is scary because ultra-processed foods are deadly. Previous studies have shown that consumption of ultra-processed foods is linked to obesity, heart disease, cancer, and Alzheimer’s disease.

The study discussed this week looked at the association between ultra-processed food consumption and type 2 diabetes. It showed:

  • There was a linear relation between ultra-processed food consumption and the development of type 2 diabetes. Simply put, the more ultra-processed food the participants consumed the more likely they were to be diagnosed with type 2 diabetes.
  • There was a 15% increased risk of developing type 2 diabetes for every 10% increase in ultra-processed food consumption.

You might be tempted to think that you can just take some medications and live with type 2 diabetes. However, you should think of type 2 diabetes as a gateway disease. It increases your risk of heart disease, high blood pressure, Alzheimer’s disease, kidney damage, and neuropathy, just to name a few. This are diseases that make your life miserable and ultimately kill you.

More importantly, type 2 diabetes is completely reversible if you catch it early enough. Just lose some weight, exercise more, give up the ultra-processed foods, and eat a healthy diet. I recommend a whole food, primarily plant-based diet.

For more details and a discussion of why Americans continue to eat ultra-processed food even though we know it is bad for us, 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 Eating Plant Protein Help You Live Longer?

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Are Whole Grains Heart Healthy?

protein and heart disease nuts and seedsThe diet wars continue. Dr. Strangelove and his colleagues are still trying to convince you that you can eat all the red meat you want. It is those deadly whole grains, beans, and fruits you need to avoid.

However, as the benefits of primarily plant-based diets continue to accumulate, it is becoming harder for them to maintain these preposterous claims.

For example, several recent studies have shown that replacing animal protein with plant protein in your diet results in better health.

  • The Iowa Women’s Health Study found that plant protein substitution for animal protein is associated with reduced risk of dying from heart disease.
  • The Nurse’s Health Study and Health Professionals Follow-up Study found that greater plant protein intake was associated with reduced risk of dying from heart disease and reduced risk of dying from all causes.
  • The Japan Public Health Center-Based Prospective Cohort Study found a reduced risk of dying from heart disease, cancer, and all causes with substitution of plant protein for red meat protein.

These were all very large studies in which populations were followed for long periods of time. You might be thinking that with such overwhelming evidence no further studies are needed.

However, these studies did not examine which plant protein sources were most beneficial and which animal protein sources were most detrimental. The study (J. Huang et al, JAMA Internal Medicine, published online July 13, 2020) I describe in today’s “Health Tips From The Professor” was designed to answer that question.

How Was The Study Done?

Clinical Study416,104 participants from the NIH-AARP Diet and Health Study were enrolled in this study in 1995 and 1996 and were followed for 16 years. At the time of enrollment, the participants filled out a comprehensive Diet History Questionnaire. The participants also completed questionnaires about their health, lifestyle, and socio-economic status.

Deaths were obtained from the Social Security Death Master File. Causes of death were obtained from the National Death Index Plus.

The basic characteristics of the study population were:

  • Gender: 57% men, 43% women.
  • Racial identification: 90% non-Hispanic white.
  • Average age 61 (range 50-71).
  • Average BMI = 27 (in the overweight range).
  • Participants were excluded from the study if they had pre-existing cancer, heart disease, stroke, or end-stage kidney disease.

In terms of protein intake:

  • Average protein intake was 15.3% of calories.
  • Plant protein contributed 40% (range 27% – 57%) to the total protein intake.
  • Animal protein contributed 60% (range = 43% to 63%) of the total protein intake.

The major sources of animal protein in the diet were:

  • Dairy products = 31.6%
  • White meat (poultry, fish, and processed white meat) = 31.3%
  • Red meat (both fresh and processed) = 30.6%
  • Eggs = 4.0%

The major sources of plant protein in the diet were:

  • Grains (bread, cereal, and pasta) = 45.8%
  • Beans and legumes = 8.0%
  • Nuts and seeds = 4.5%
  • Other plant protein (including plant protein from supplements) = 41.7%

All these protein intake figures are normal for the American diet.

I should note that beans, nuts, and seeds are among the best sources of plant protein. However, they are only a minor part of the typical American diet, so they contribute relatively little to our plant protein intake.

Does Eating Plant Protein Help You Live Longer?

In terms of overall protein intake, this study mirrored previous studies.

  • There was an inverse association between plant protein intake and premature death from heart disease, stroke, and all causes. Put another way, the more plant protein people in this study ate, the lower was their risk of premature death.

To quantify the effect, the investigators asked what happened when 3% of calories came from plant protein instead of animal protein. I recognize, however, that 3% of calories is a rather abstract concept, so let me break it down for you so you can apply it to your lives.

  • For participants in this study, protein was 15% of their total calories. That means when the investigators were talking about shifting 3% of total calories from animal protein to plant protein, they were talking about 20% of the protein in the diet coming from plant protein rather animal protein.
  • Based on the average caloric intake of participants in this study, that corresponds to 15 grams of protein for men and 12 grams of protein for women.

With that in mind, let’s look at the results:

  • Changing just 3% of calories from animal protein to plant protein:
  • Lowered the risk of premature death from all causes by 10% for both men and women.
  • Lowered the risk of premature death from cardiovascular disease by 11% for men and 12% for women.
  • Lowered the risk of premature death from stroke by 22% for men and 19% for women.

These findings are consistent with previous studies. By now, it should be apparent that primarily plant-based diets are best for your overall health. Primarily plant-based diets also appear to reduce your risk of dying prematurely from heart disease and from all other diseases combined.

The authors concluded: “This large cohort investigation showed small but significant associations between higher intake of plant protein and lower overall and cardiovascular mortality…Findings from this and previous studies provide evidence that dietary modifications in choice of protein sources may promote health and longevity.”

However, this part of the study merely confirms what other studies have shown. What makes this study unique is that it identifies which animal proteins are worst for us and which plant proteins are best for us.

Which Animal Proteins Are Least Heart Healthy?

Animal Protein FoodsLet’s start with the animal proteins (Note: To simplify a complex set of data, I am going to average the results for men and women).

  • Changing 3% of calories from egg protein to plant protein:
    • Lowered the risk of premature death from all causes by 23%.
    • Lowered the risk of premature death from cardiovascular disease by 27%.
    • To put this into perspective, 3% of calories from egg protein corresponds to around 2.5 eggs/day. So, talking about replacing 3% of calories of egg protein creates a false narrative. The average egg consumption in this study was 0.5 eggs/day and very few participants consumed even 2 eggs every day. If we make a more reasonable comparison, replacing one egg/day with an equivalent amount of plant protein:
      • Lowers the risk of premature death from all causes by 9%.
      • Lowers the risk of premature death from cardiovascular disease by 11%.
  • Changing 3% of calories from red meat protein to plant protein:
    • Lowered the risk of premature death from all causes by 14%.
    • Lowered the risk of premature death from cardiovascular disease by 12%.
    • Lowered the risk of premature death from stroke by 21%.
    • To put this into perspective, 3% of calories from red meat protein corresponds to around 2 ounces/day.
  • Changing 3% of calories from dairy protein to plant protein:
    • Lowered the risk of premature death from all causes by 8%.
    • Lowered the risk of premature death from cardiovascular disease by 11%.
    • Lowered the risk of premature death from stroke by 21%.
    • To put this into perspective, 3% of calories from dairy protein corresponds to around 1.7 8-ounce glasses of milk, 2 ounces of cheese, or 1 cup of yogurt (most yogurt “cups” sold commercially are less than an 8-ounce cup).
  • Changing 3% of calories from white meat protein to plant protein had no effect on premature death from any disease in this study. I will discuss the reasons for that below.

Are Whole Grains Heart Healthy?

Whole GrainsNow, let’s look at the flip side. What happens when you replace 3% of calories from red meat protein with various kinds of plant protein?

  • Changing 3% of calories from red meat protein to plant protein from whole grains:
    • Lowered the risk of premature death from all causes by 28%.
    • Lowered the risk of premature death from cardiovascular disease by 32%.
    • Lowered the risk of premature death from stroke by 32%.
    • To put this into perspective, 3% of calories from whole grain protein corresponds to around 2.5 slices of whole grain bread, 2 cups of oatmeal, or 2.5 cups of brown rice or whole grain pasta – or any combination of them during the day.
  • The results were similar for replacing egg protein with whole grain protein.
  • Changing 3% of calories from red meat protein or egg protein to other types of plant protein had no effect on premature death from any disease. The reasons for that will be discussed below.

The authors concluded “…this investigation showed prominent inverse associations between overall and cardiovascular mortality and the replacement of egg protein and red meat protein with plant protein, particularly for plant protein derived from bread, cereal, and pasta…”

Why Do Animal Proteins Increase Your Risk Of Premature Death?

Let me take a deep dive into the data. If you like, you can skip to “What Does This Study Mean For You?”

To help you gain a better understanding of these results, I will answer two questions for you:

  • Mechanism: What is/are the metabolic explanation(s) for these results?
  • Perspective: How can you apply this information to your own life?

Reminder: This section is for those of you who want the details. I will give the Cliff Notes summary in the section “What Does This Study Mean For You”.

EggsEggs

Mechanism:

  • The bad effect of eggs on cardiovascular mortality and all-cause mortality is thought to be almost exclusively due to their high cholesterol content.
  • On the flip side, eggs are an excellent source of low-fat animal protein and provide nutrients like choline and carotenoids that are often insufficient in the American diet.

Perspective:

  • Our bodies have a beautifully designed system for regulating blood cholesterol levels. This means under ideal conditions dietary cholesterol has very little effect on blood cholesterol levels. However, as I have pointed out in a previous issue of “Health Tips From the Professor”, conditions are often far from ideal.
  • Diet context matters. Obesity, saturated fat, and sugar all interfere with our ability to regulate blood cholesterol levels. People consuming the typical American diet, like the ones in this study, have more difficulty regulating their blood cholesterol levels and are more likely to be adversely affected by dietary cholesterol from eggs and other high-cholesterol foods.
    • Previous studies suggest that adding eggs to the typical American diet may increase risk of cardiovascular disease and premature death.
    • In contrast, adding eggs to a primarily plant-based diet, such as found in China and Japan, appears to decrease risk of heart disease and premature death.

Red Meatfatty steak

Mechanisms: The mechanism(s) associated with the bad effects of red meat are less clear. Here are the potential mechanisms discussed by the authors of this study.

  • Red meat is high in cholesterol. While many experts have downplayed the importance of dietary cholesterol in recent years, it still may be of concern in the context of the typical American diet because of our body’s inability to regulate cholesterol metabolism normally.
  • Red meat is high in saturated fat. While some experts have downplayed the importance of reducing saturated fat intake, I pointed out in a previous issue of “Health Tips From the Professor” that it depends on what the saturated fat is replaced with.
    • When saturated fats are replaced with sugar and refined carbohydrates in the typical American diet, reducing saturated fat is of no benefit.
    • When saturated fats are replaced with polyunsaturated fats in the context of a primarily plant-based diet, such as the Mediterranean diet, reducing saturated fats leads to a substantial reduction in the risk of heart disease and premature death.
  • Red meat also contains heme iron which is associated with 57% increased risk of cardiovascular disease.
  • Diets high in red meat result in populations of gut bacteria that are associated with increased risk of cardiovascular disease. This is most likely because red meat is displacing plant foods that support the growth of healthy bacteria.
  • As discussed in a recent issue of “Health Tips From the Professor”, the gut bacteria associated with red meat consumption convert the L-carnitine in red meat to a metabolite called trimethylamine N-oxide (TMAO) which appears to significantly increase the risk of cardiovascular disease.
  • Finally, a recent study suggests that foods high in sulfur-containing amino acids significantly increase risk of cardiovascular disease. However, this mechanism is not specific for red meat. White meat, beans, and legumes are also high in sulfur-containing amino acids.

Perspective:

  • While the exact mechanism(s) is/are uncertain, there is substantial evidence from multiple studies that red meat consumption increases the risk of premature death from cardiovascular disease and from all causes.
  • Grass fed beef is not a “get out of jail free card”. Grass fed beef is modestly lower in cholesterol and saturated fat. However, those are only two of six potential mechanisms for the link between red meat consumption and cardiovascular disease.
  • However, those of you who, like me, enjoy red meat should not consider this to be an absolute “red meat should never touch your lips” edict. As I have discussed in a previous issue of “Health Tips From the Professor”, the health effects of red meat are a matter of quantity and diet context.
    • If you are thinking in terms of a juicy 8-ounce steak with a baked potato and sour cream, red meat is probably not a healthy choice.
    • However, if you are thinking of 2-3 ounces of lean steak in a vegetable stir fry or a green salad, red meat may be a healthier choice.

dairy products and heart diseaseDairy: I have reported on the health risks and benefits of dairy foods in a previous issue of “Health Tips From the Professor”, so I will just give you a brief summary here.

Perspective:

  • Eating dairy foods, even high-fat dairy foods, has relatively little effect on cardiovascular disease risk in the context of the typical high-fat, high-sugar American diet.
  • Eating dairy foods, even high-fat dairy foods, in the context of a healthy plant-based diet appears to lower cardiovascular disease risk.
  • As this study suggests, moving towards a more plant-based diet by substituting some plant protein for dairy protein in the diet will also decrease your risk of cardiovascular disease

White Meat: This and previous studies suggest that white meat is less likely than red meat to increase the risk of cardiovascular disease and premature death. I have discussed the differences between red and white meat in a previous issue of “Health Tips From the Professor”. However, I can summarize the differences best here by going back to the mechanisms associated with the link between red meat and cardiovascular diseases and highlight those that do not apply to white meat.

Mechanisms:

  • Saturated fat. Many fish are much lower in saturated fat and are excellent sources of heart-healthy omega-3 fats. Chicken and turkey breast with the skin removed are also much lower in saturated fat than red meat.
  • Heme iron. Chicken breast is lower in heme iron than red meats.
  • TMAO. White meats contain 10-50 times less L-carnitine than red meats. Since L-carnitine is the precursor of TMAO, they are much less likely to cause TMAO production.

Why Do Plant Proteins Decrease Your Risk Of Premature Death?

Whole Grains: Whole grains have been much maligned in recent years. They have been lumped in with sugar and refined grains and have been added to everyone’s “naughty list”.

  • If you are following a low-carb diet, you are told to avoid all grains.
  • If you are following a Paleo diet, you are told our paleo ancestors ate no grains.
  • If you are trying to avoid lectins…you get the point.

That’s unfortunate, because whole grains are very healthy. In a recent issue of “Health Tips From the Professor” I shared a study showing that whole grain consumption reduced the risk of premature death from heart disease, cancer, and all causes. The current study shows essentially the same thing.

The only question is why whole grains are uniquely effective at decreasing premature death from cardiovascular disease and all causes in this study. Why aren’t all plant proteins equally effective? I will share both a suggested mechanism and perspective.

Mechanism:

  • In a recent issue of “Health Tips From The Professor” I reported a study showing that grains and a few other foods contain a unique type of fiber called resistant starch that suppress growth of the gut bacteria which convert L-carnitine to TMAO. This may be why whole grains are uniquely effective at reducing the risk of cardiovascular disease and premature death.
  • Some refined grains are also good sources of resistant starch. However, I don’t recommend them because they lack the antioxidants, vitamins, phytonutrients, and insoluble fiber found in whole grains.

Perspective:  

The fact no other plant protein source significantly reduced heart disease risk in this study is most likely an artifact of the study.

  • The study asked what happens when you change 15 grams of the protein in your diet from red meat protein to different kinds of plant protein. That question was easy to answer for grains because they are a major source of protein in the American diet. However, Americans don’t get enough protein from other high protein plant foods like beans and legumes or nuts and seeds to provide a statistically valid answer to that question.
  • However, all plant foods have their own health benefits. They are excellent sources of antioxidants and phytonutrients that provide heart health benefits.
  • In addition, each plant food provides a different blend of fibers and supports different populations of gut bacteria with different health benefits. For example, fiber from fruits and vegetables is associated with a lower risk of cancer.

What Does This Study Mean For You?

dairy products and heart disease questionsA recent study has shown that changing as little as 20% of the protein in our diet from animal protein to plant protein significantly reduces our risk of premature death from cardiovascular disease, stroke, and from all causes.

The effect of replacing 2 ounces of red meat, 1 egg, or 2 servings of dairy with an equivalent amount of plant protein was equally beneficial.

Previous studies show that diet context is important. A small amounts of animal protein in the context of a whole food, primarily plant-based diet is much less likely to cause harm and may provide benefit. For example:

  • Eggs are high in cholesterol but are also excellent sources of low-fat protein and nutrients that may be missing in a plant-based diet.
    • Previous studies suggest that adding eggs to the typical American diet may increase risk of cardiovascular disease and premature death.
    • In contrast, adding eggs to a primarily plant-based diet, such as found in China and Japan, appears to decrease risk of cardiovascular disease and premature death.
  • Dairy foods are high in saturated fat but are excellent sources of calcium, vitamin D, and other nutrients that may be missing in a plant-based diet.
    • Eating dairy foods, even high-fat dairy foods, has relatively little effect on cardiovascular disease risk in the context of the typical high-fat, high-sugar American diet.
    • Eating dairy foods, even high-fat dairy foods, in the context of a healthy plant-based diet appears to lower cardiovascular disease risk.
  • Red meat has multiple suggested mechanisms for it increasing the risk of death from cardiovascular disease. However, diet context still matters.
    • If you are thinking in terms of a juicy 8-ounce steak with a baked potato and sour cream, red meat is probably not a healthy choice.
    • However, if you are thinking of 2-3 ounces of lean steak in a vegetable stir fry or a green salad, red meat may be a healthier choice.
    • Grass fed beef should not be considered a “get out of jail free card”. Grass fed beef is modestly lower in cholesterol and saturated fat. However, those are only two of six potential mechanisms for the link between red meat consumption and cardiovascular disease.
  • White meat does not appear to affect your risk of developing cardiovascular disease.
  • Whole grains significantly decreased the risk of premature death from cardiovascular disease and death from all causes. This may be because whole grains contain a unique type of fiber called resistant starch that suppresses the growth of the gut bacteria which convert L-carnitine to a heart-damaging compound called TMAO.
    • Notice that I specified “whole grain”. While some refined grains are also a good source of resistant starch, they lack the other heart healthy nutrients and phytonutrients found in whole grains.
      • Wonder Bread, Frosted Flakes, Honey Bunches of Oats, and white-flour pasta are not on my approved list. I agree with low-carb enthusiasts about eliminating them from our diets.
      • You should also be aware that “whole grain” on the label means nothing. You want to choose foods that say “100% whole grain”.
    • Finally, this study only focused on plant protein sources. It is important to remember that other plant foods are an excellent source of antioxidants, phytonutrients, and fiber. Each plant food provides unique heart health benefits.

The Bottom Line

A recent study has shown that changing as little as 20% of the protein in our diet from animal protein to plant protein significantly reduces our risk of premature death from cardiovascular disease, stroke, and from all causes.

The effect of replacing 2 ounces of red meat, 1 egg, or 2 servings of dairy with an equivalent amount of plant protein was equally beneficial. White meat did not affect the risk of cardiovascular disease or premature death.

  • Grass fed beef should not be considered a “get out of jail free card”. Grass fed beef is modestly lower in cholesterol and saturated fat. However, those are only two of six potential mechanisms for the link between red meat consumption and cardiovascular disease.
  • Diet context is important. Small amounts of animal protein in the context of a whole food, primarily plant-based diet appear to be much healthier for us than large amounts of animal protein in the context of the high-fat, high-sugar American diet.

On the flip side of the equation, whole grains significantly decreased the risk of premature death from cardiovascular disease and death from all causes. This has also been seen in other recent studies.

  • Notice that I specified “whole grain”. Wonder Bread, Frosted Flakes, Honey Bunches of Oats, and white-flour pasta are not on the list.
  • You should also be aware that “whole grain” on the label means nothing. You want to choose foods that say “100% whole grain”.
  • Finally, this study only focused on plant protein sources. It is important to remember that other plant foods are an excellent source of antioxidants, phytonutrients, and fiber. Each plant food provides unique heart health benefits.

For more details, read the article above, especially the “What Does This Study Mean For You?” section.

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.

What Is The Truth About Eating Eggs And Heart Disease?

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Have The Dangers Of Eggs Been “Eggagerated”?

egg confusionIt’s no wonder you are confused about whether or not eggs are good for you. The advice you have been given about eggs over the years has been constantly changing.

Eggs are an affordable source of high-quality protein, iron, unsaturated fats, phospholipids like lecithin and choline, and carotenoids. That almost qualifies them as a health food. However, they are also a major source of cholesterol in the American diet. Back when we thought of dietary cholesterol was bad for us, that made eggs the enemy.

Then we discovered that dietary cholesterol has relatively little effect on blood cholesterol levels. It was obesity plus saturated fat and sugar in our diet that raised blood cholesterol levels and increased our risk of heart disease.

Then several studies reported that eggs did not increase our risk of heart disease. A study out of China even found that eggs decreased the risk of heart attack and hemorrhagic stroke. Suddenly, eggs became our best friend.

That only lasted a few years until a study from the United States reported that eggs increased your risk of heart disease, and a study from Europe reported that eggs increased your risk of hemorrhagic stroke. Eggfusion (egg confusion) reigned.

Most of these studies were large studies. They followed their participants for 5-10 years. Why were their results so confusing? A careful analysis of the studies shows that most of them suffered from three major weaknesses.

  • They only measured egg consumption at the beginning of the study. This fails to account for the fact that egg consumption has waxed and waned over the years as eggs have gone from enemy to friend and back to enemy.
  • They did not assess how the overall diet influences the effect of egg consumption on heart disease. If we believe the previous studies, eggs lower the risk of heart disease and hemorrhagic stroke in China and increase the risk of both in the United States and Europe. This suggests that overall diet is important, but this hypothesis has not been tested.
  • They also did not address the question of whether eggs, because of their cholesterol, might have a more adverse effect on heart disease in individuals who already have high blood cholesterol and have difficulty controlling their cholesterol levels.

That is why the study (JP Drouin-Chartier et al, British Medical Journal, 368:m513, 2020) I am reporting on today is so important. It is a huge study, much larger than any previous study on the topic. Plus, it was designed in such a way that it had none of the weaknesses of previous studies.

How Was The Study Done?

Clinical StudyThis study started by combining the data from three major clinical trials:

  • The first Nurse’s Health Study, which ran from 1980 to 2012,
  • The second Nurse’s Health Study, which ran from 1991-2013, and
  • The Health Professional’s Follow-Up Study, which ran from 1986-2012.

These studies combined enrolled 173,563 women and 42,055 men and followed them for an average of 32 years. All the participants were free of heart disease, type 2 diabetes, and cancer at the time they were enrolled. The design of these studies was extraordinary.

  • A detailed food frequency questionnaire was administered every 2-4 years. This allowed the investigators to calculate cumulative averages of all dietary variables, including egg intake. This assured that the effects of egg consumption and diet represented the participant’s diet over the 32-year duration of the study.
  • Participants also filled out questionnaires that captured information on disease diagnosis, disease risk factors, medicines taken, weight, and lifestyle characteristics every 2 years with follow-up rates >90%. This allowed the investigators to measure the onset of disease and medicine use for each participant during the study. More importantly, 32 years is long enough to measure the onset of diseases like heart disease, diabetes, and cancer – diseases that require decades to develop.
  • The endpoint of the study was “incident heart disease”, which the investigators defined as non-fatal heart attack, death from heart disease, and fatal and non-fatal stroke. During this study, 14,806 participants developed incident heart disease. This was a large enough number for a detailed statistical analysis of the data.
  • For example, statistical analysis showed that the participants with the highest egg intake also were more likely to be obese and more likely to consume red meat, bacon and other processed meats, refined grains, French fries, and sugar-sweetened beverages. These are what we refer to as “confounding variables” because they also increase the risk of heart disease and are likely to confound (confuse) the analysis. Therefore, the investigators statistically corrected the data on egg consumption for these confounding variables. Many previous studies did not have the data or statistical power to correct their egg consumption data for these confounding variables.

In short, this study was much larger, ran far longer, and was better designed that any of the previous studies on egg consumption and heart disease risk. However, the authors did not stop there. They also performed a meta-analysis of 28 previous studies with a total of 1,720,108 participants and 139,195 cardiovascular disease events.

The only weakness in this study is that only 2% of the participants ate more than one egg per day. Consequently, it cannot address the health consequences of eating more than one egg per day on a regular basis.

Before sharing the results of this study with you, I need to provide some background about how our bodies regulate blood cholesterol levels. So, let’s move on to my favorite topic, “Biochemistry 101”.

Biochemistry 101: Cholesterol Metabolism

ProfessorMost people think of cholesterol only as a bad thing – something that can kill us. Nothing could be further from the truth. In fact, cholesterol is essential for life.

  • Our body makes vitamin D and coenzyme Q10 from cholesterol.
  • Our body makes steroid hormones such as cortisol, estrogen, and testosterone from cholesterol.
  • Cholesterol is a vital component of the myelin sheath that coats our nerve cells.
  • And that is just the beginning.

Because cholesterol is essential, our body makes its own cholesterol and has an elegant control system that keeps our blood cholesterol levels right where they should be.

  • When we get lots of cholesterol from our diet, our body makes less and excretes any excess.
  • When we get little cholesterol from our diet, our body makes more and excretes less.

Unfortunately, many Americans muck up this elegant control system. There are several factors that can throw our body’s ability to regulate blood cholesterol levels out of whack, leading to elevated blood cholesterol levels and increased risk of heart disease. For example:

  • Obesity
  • Type 2 diabetes
  • Diets high in saturated fats
  • Diets high in sugar and refined carbohydrates
  • Genetics

And it’s not just elevated cholesterol that is the problem. These same factors are associated with inflammation, which also increases the risk of heart disease.

Of course, we can’t do anything about our genetics, but the other factors are under our control. Let’s keep that in mind as we look at the results of this study.

What Is The Truth About Eating Eggs And Heart Disease?

the truth signWhen the investigators looked at their combined data from the Nurse’s Health Studies and the Health Professional’s Study:

  • There was no difference in heart disease outcomes for participants consuming an average of one egg/day and participants consuming less than one egg/month.
  • When the investigators examined heart attack and stroke separately, there was no difference in either outcome for participants consuming an average of one egg/day and participants consuming less than one egg/month.
  • As mentioned above the participants who consumed the most eggs weighed more; were less physically active; were more likely to be current smokers; and were more likely to consume red meat, processed meats, refined grains, potatoes (think French fries and potato chips), full fat milk, and sugar-sweetened beverages.
    • Without correcting for these factors eating one egg/day resulted in a 10% increase in heart disease risk.
    • After correcting for these factors, eating one egg/day resulted in a 7% decrease in heart disease risk.
    • In both cases the differences were statistically non-significant. However, they were in line with the previous studies mentioned above.

When they looked at the data generated by their meta-analysis of 28 studies:

  • There was no association between heart disease risk and egg consumption.
    • In Asian countries where the diet was primarily unrefined, plant-based foods, egg consumption decreased heart disease risk.
    • In people with type 2 diabetes, egg consumption increased heart disease risk.

The authors concluded “…moderate egg consumption (up to one egg/day) is not associated with cardiovascular disease risk overall, and is associated with potentially lower cardiovascular disease risk in Asian populations.”

The authors also noted that their data did not allow them to evaluate the effect of consuming more than one egg/day.

Have The Dangers Of Eggs Been “Eggagerated”?

are eggs good for youThis study clears up a lot of confusion about egg consumption and heart disease risk. The problem is that the scientific and medical communities have been looking for a “one size fits all” recommendation about egg consumption. This study shows us that the reality is much more complicated. Let me describe my interpretation of the data.

I think the results of this and previous studies are best described by the phrase, “Eggs are a healthy part of a healthy diet”. Here is what I mean by that.

  • If you are consuming a primarily plant-based diet, your body is fully able to regulate your blood cholesterol levels. Then, you can reap the full benefits of the egg, namely the protein, iron, unsaturated fats, lecithin, choline, and carotenoids it provides. Under these conditions, eating up to one egg/day reduces your risk of heart disease.
  • If you are consuming a diet that contains primarily chicken or fish and unprocessed plant foods, egg consumption is neutral. It neither increases nor decreases your risk of heart disease.
  • If you are consuming a diet that contains sugar-sweetened beverages, red and processed meats, high fat dairy products, refined grains, and junk foods (ie, the typical American diet), your body is no longer able to regulate blood cholesterol levels well. Now the cholesterol content of eggs becomes an issue and consuming one egg/day slightly increases your risk of heart disease.
  • If you are overweight and have developed type 2 diabetes, your body has become insulin resistant. This also interferes with your body’s ability to regulate blood cholesterol levels. In this situation, consuming one egg/day also increases your risk of heart disease.

The caveat is, of course, that these conclusions are based averages, and none of us are average.

The Bottom Line

You are probably aware that the effect of egg consumption on heart disease risk is controversial. Some studies report that egg consumption has no effect on heart disease risk. Other studies report egg consumption decreases heart disease risk. Still other studies report that egg consumption increases heart disease risk. No wonder you are confused.

A recent study has cleared up much of the confusion. This was not just another study. This study was much larger, ran far longer, and was better designed that any of the previous studies.

If you look at this and previous studies, it becomes clear that the effect of egg consumption on heart disease risk is strongly influenced by your overall diet and lifestyle.

  • If you are consuming a primarily plant-based diet, your body is fully able to regulate your blood cholesterol levels. Then, you can reap the full benefits of the egg, namely the protein, iron, unsaturated fats, lecithin, choline, and carotenoids it provides. Under these conditions, eating up to one egg/day reduces your risk of heart disease.
  • If you are consuming a diet that contains primarily chicken or fish and unprocessed plant foods, egg consumption is neutral. It neither increases nor decreases your risk of heart disease.
  • If you are consuming a diet that contains sugar-sweetened beverages, red and processed meats, high fat dairy products, refined grains, and junk foods (ie, the typical American diet), your body is no longer able to regulate blood cholesterol levels well. Now the cholesterol content of eggs becomes an issue and consuming one egg/day slightly increases your risk of heart disease.
  • If you are overweight and have developed type 2 diabetes, your body has become insulin resistant. This also interferes with your body’s ability to regulate blood cholesterol levels. In this situation, consuming one egg/day also increases your risk of heart disease.

In short, eggs are a healthy part of a healthy diet.

For more details, read the article above. You may also want to read the section “Biochemistry 101: Cholesterol Metabolism” to gain a better understanding of the mechanism behind these statements.

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

Can Vitamin C Prevent Heart Disease?

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Where Should I Get My Vitamin C?

vitamin CThe vitamin C controversy continues. Some people call vitamin C a “miracle” nutrient. Others consider it little more than “fairy dust”. What is the truth?

Let’s look at the effect of vitamin C on heart disease risk as an example of why it is so difficult to resolve questions like this.

Association studies are ideal for measuring long-term effects of nutrient consumption on health outcomes. These studies have consistently found an inverse association between dietary vitamin C and plasma vitamin C levels with the risk of heart disease. Simply put, the more vitamin C from dietary sources, the lower the risk of heart disease.

However, association studies do not prove cause and effect. The primary reason for this is that association studies are complicated by “confounding variables”. For example, most vitamin C in the diet comes from fruits and vegetables. So, the question arises, “Is it the vitamin C in fruits and vegetables that is responsible for the decreased heart disease risk, or is it the fiber that is also present in fruits and vegetables?” Previous studies have not been designed to answer this question.

Placebo-controlled clinical trials solve the confounding variable issue because they involve supplementation with pure vitamin C or a placebo. There is only a single variable. However, placebo-controlled clinical trials only last for a short time. That means they can measure biological markers that may affect heart disease risk but seldom last long enough to directly measure the effect of vitamin C on heart disease risk.

For example, previous studies have shown that high-dose (500 to 4,000 mg/day) supplementation with vitamin C improves the function of the endothelial lining of our blood cells and reduces blood pressure. These are biological markers that might be expected to reduce heart disease risk.

However, heart disease takes decades to develop. No studies of vitamin C supplementation have lasted long enough to show an actual decrease in heart disease outcomes.

In today’s issue of “Health Tips From The Professor” I would like to address three questions:

1) Does dietary vitamin C reduce heart disease risk?

2) How much of the risk reduction is due to the fiber content of fruits and vegetables rather than their vitamin C content?

3) Does supplementation with vitamin C reduce heart disease risk?

I will focus on a recent study (N Martin-Calvo and MA Martinez-Gonzalez, Nutrients, 9: 954, 2017, doi.org/10.3390/nu909054) that was designed to answer these questions.

How Was The Study Done?

Heart Health StudyThis study was an offshoot of an ongoing Spanish research program called Seguimiento Universidad de Navarra (SUN) follow-up study. This program is following graduates of the University of Navarra to gauge the effect of diet and lifestyle on health outcomes.

Health, lifestyle, and diet information is collected when graduates enroll in the program and by mailed questionnaires every two years thereafter.

Graduates who were enrolled in the SUN program in 2014 or earlier were invited to participate in this vitamin C and heart disease study.

  • Vitamin C intake from diet and from supplements was assessed from the dietary analysis.
  • A diagnosis of heart disease was obtained from the Health questionnaire and confirmed by physician follow-up.
  • Deaths due to heart disease were obtained from the Spanish National Death Index cross-referenced to participants in the study and were confirmed by participants next of kin, work associates, or postal authorities.

The study excluded:

  • Participants with pre-existing heart disease at the beginning of the study.
  • Participants who were younger than 40 at the beginning of the study.
  • Participants with either very high or very low vitamin C intake.

That left 13,421 participants who were young (average age = 42), at a healthy weight (average BMI = 24), healthy, and taking few medications.

Can Vitamin C Prevent Heart Disease?

Healthy HeartThe 13,421 participants in this study were followed for an average of 11 years.

They were divided into three groups based on their vitamin C intake.

  • Group 1 averaged 148 mg/day.
  • Group 2 averaged 257 mg/day.
  • Group 3 averaged 445 mg/day.

There are two noteworthy observations about their vitamin C intake:

  • None of the groups were vitamin C deficient. All three groups were getting well above the RDA for vitamin C (75 mg/day for women and 90 mg/day for men).
  • Most of the vitamin C came from fruits and vegetables in the diet. The group with the highest vitamin C intake (445 mg/day) only averaged about 10 mg/day from supplements.

The results of the study were intriguing. When the investigators compared the group with the highest vitamin C intake to the group with the lowest vitamin C intake:

  • Vitamin C significantly decreased both the risk of developing heart disease and the risk of dying from heart disease.
    • Statistically adjusting the data for age, gender, weight, lifestyle, and medicine use did not affect the outcome.
    • Statistically adjusting the data for fiber from sources other than fruits and vegetables did not affect the outcome.
    • Statistically adjusting the data for adherence to a healthy diet (the Mediterranean diet) did not affect the outcome.

However, when the data were statistically adjusted for total fiber (including fiber from fruits and vegetables) the high fiberresults painted a slightly different picture. With this adjustment:

  • Vitamin C decreased the risk of developing heart disease by 26%, but this decrease was not statistically significant.
  • Vitamin C decreased the risk of dying from heart disease by 70%, and this decrease was highly significant.

This was the first study to consider the relative importance of vitamin C from fruits and vegetables and fiber from fruits and vegetables on heart disease outcomes and the results were interesting. Here are the important conclusions.

1) Both the fiber and the vitamin C from fruits and vegetables contributed to a decreased risk of developing heart disease. This study was unable to separate their contributions.

Of course, it is important to note that this was a young, healthy population, none of whom were deficient in vitamin C. It would be interesting to repeat this study with an older, sicker population with a more restrictive diet.

2) Vitamin C from fruits and vegetables reduced the risk of dying from heart disease independent of the beneficial effects of fruit and vegetable fiber.

3) This study was not able to address the effect of vitamin C supplementation on heart disease risk. That is because the Spaniards supplement much less frequently than Americans and this study excluded anyone with unusually high vitamin C intake. The average supplemental vitamin C in the 3 groups ranged from 0.56 mg/day to 9.6 mg/day.

4) This study also emphasizes the importance of getting fiber from a variety of food sources. It showed that fiber from fruits and vegetables was more beneficial at reducing heart disease risk than fiber from other food sources. That means restrictive diets that eliminate fruits and/or vegetables may be bad for your heart.

Where Should I Get My Vitamin C?

Vegan FoodsThis study reinforces the importance of getting lots of fresh fruits and vegetables in your diet.

  • You could make a list of all the vitamin C-rich fruits and vegetables like citrus fruits, red & green peppers, broccoli, etc. and make sure you are including them in your diet.
  • You could total up the vitamin C in each food you eat and try to reach the 445 mg/day in the group with the highest vitamin C in this study.

However, it doesn’t have to be that complicated. If you eat a primarily plant-based diet, aim for 5-9 servings of fruits and vegetables a day, and “eat the rainbow” you will get plenty of vitamin C from your diet.

Also, don’t worry about whether the benefits of fruit and vegetable consumption come from their vitamin C or from their fiber. That’s the beauty of eating whole foods. You get both in the same package.

Of course, you are probably also wondering whether vitamin C supplementation will reduce your risk of heart disease. As I described earlier, there are lots of reasons for thinking that vitamin C supplementation might decrease heart disease risk.

  • Several studies show that higher vitamin C intake and higher vitamin C levels in the blood are associated with lower heart disease risk.
  • This study showed that vitamin C reduces the risk of dying from heart disease independent of fiber from fruits and vegetables and independent of an overall healthy diet. This suggests that vitamin C plays an independent role in reducing heart disease risk.
  • Placebo controlled clinical trials show that vitamin C supplementation reduces risk factors that contribute to heart disease.

However, none of these studies prove that vitamin C supplementation reduces heart disease risk. That requires placebo-controlled clinical trials measuring the effect of vitamin C supplementation on heart disease outcomes. Unfortunately, these studies are usually doomed to failure.

Chronic diseases like heart disease takes decades to develop. Placebo-controlled, randomized studies are almost never large enough or last long enough to show an effect of supplementation on chronic diseases.

The best we can say at present is that vitamin C supplementation along with a primarily plant-based diet with lots of colorful fruits and vegetables may reduce your risk of heart disease.

The Bottom Line

A recent study in Spain followed 13,421 healthy college graduates with an average age of 42 for 11 years and looked at the effect of vitamin C intake on the risk of developing heart disease and the risk of dying from heart disease.

This was the first study to consider the relative importance of vitamin C from fruits and vegetables and fiber from fruits and vegetables on heart disease outcomes and the results are intriguing. Here are the important conclusions.

1) Both the fiber and the vitamin C from fruits and vegetables contributed to a decreased risk of developing heart disease. This study was unable to separate their contributions.

Of course, it is important to note that this was a young, healthy population, none of whom were deficient in vitamin C. It would be interesting to repeat this study with an older, sicker population with a more restrictive die

2) Vitamin C from fruits and vegetables reduced the risk of dying from heart disease by 70%, and this effect was independent of the beneficial effects of fruit and vegetable fiber.

3) This study was not able to address the effect of vitamin C supplementation on heart disease risk. That is because the Spaniards supplement much less frequently than Americans and this study excluded anyone with unusually high vitamin C intake. The average supplemental vitamin C in the 3 groups ranged from 0.56 mg/day to 9.6 mg/day.

4) This study also emphasizes the importance of getting fiber from a variety of food sources. It showed that fiber from fruits and vegetables was more beneficial at reducing heart disease risk than fiber from other food sources. That means restrictive diets that eliminate fruits and/or vegetables may be bad for your heart.

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.

Should I Avoid Whole Grains?

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Will Whole Grains Kill Me?

Whole GrainsIt seems like just yesterday that health experts all agreed that whole grains were good for us. After all:

  • They are a good source of fiber, B vitamins, vitamin E, and the minerals magnesium, iron, zinc, manganese, and selenium.
  • Their fiber fills you up, so you are less likely to overeat. This helps with weight control.
  • Their fiber also supports the growth of friendly bacteria in your gut.

In fact, the USDA still recommends that half of the grains we eat should be whole grains. And, outside experts, not influenced by the food industry, feel this recommendation is too low. They feel most of the grains we eat should be whole grains. Foods made from refined grains should be considered as only occasional treats.

Then the low-carb craze came along. Diets like Paleo and Keto were telling you to avoid all grains, even whole grains. Even worse, Dr. Strangelove and his colleagues were telling you whole grains contained something called lectins that were bad for you. Suddenly, whole grains went from being heroes to being villains.

You are probably asking, “Should I avoid whole grains?” What is the truth? Perhaps the best way to resolve this debate is to ask, how healthy are people who consume whole grains for many years? This week I share a recent study (G Zong et al, Circulation, 133: 2370-2380, 2016) that answers that very question.

How Was The Study Done?

This study was a meta-analysis of 14 clinical trials that:

  • Enrolled a total of 786,076 participants.
  • Obtained a detailed diet history at baseline.
  • Followed the participants for an average of 15 years (range = 6-28 years).
  • Determined the effect of whole grain consumption on the risk of death from heart disease, cancer, and all causes.

Will Whole Grains Kill Me?

deadDr. Strangelove and his colleagues are claiming that whole grains cause inflammation, which increases your risk of heart disease and cancer. Heart disease and cancer are the leading causes of death in this country. In fact, according to the CDC, heart disease and cancer accounted for 44% of all deaths in the US in 2017.

Therefore, if Dr. Strangelove and his colleagues were correct, consumption of whole grains should increase the risk of deaths due to heart disease and cancer – and increase the risk of death due to all causes.

That is not what this study showed.

When the highest whole grain intake (5 servings/day) was compared with the lowest whole grain intake (0 servings/day), whole grain consumption reduced the risk of death from:

  • Heart disease by 18%.
  • Cancer by 12%.
  • All causes by 16%.

Furthermore, the effect of whole grains on mortality showed an inverse dose response. Simply put, the more thumbs upwhole grains people consumed, the lower the risk of deaths from heart disease, cancer, and all causes.

However, the dose response was not linear. Simply going from 0 servings of whole grains to one serving of whole grains reduced the risk of death from.

  • Heart disease by 9%.
  • Cancer by 5%.
  • All causes by 7%.

The authors concluded: “Whole grain consumption was inversely associated with mortality in a dose-response manner, and the association with cardiovascular mortality was particularly strong and robust. These observations endorse current dietary guidelines that recommend increasing whole grain intake to replace refined grains to facilitate long-term health and to help prevent premature death.”

The authors went on to say: “Low-carbohydrate diets that ignore the health benefits of whole grain foods should be adopted with caution because they have been linked to higher cardiovascular risk and mortality.”

Should I Avoid Whole Grains?

Question MarkAs for the original question, “Should I avoid whole grains?”, the answer appears to be a clear, “No”.

The strengths of this study include the large number of participants (786,076) and the demonstration of a clear dose-response relationship between whole grain intake and reduced mortality.

This study is also consistent with several other studies that show whole grain consumption is associated with a lower risk of heart disease, diabetes, cancer – and appears to lead to a longer, healthier life.

In short, it appears that Dr. Strangelove and the low-carb enthusiasts are wrong. Whole grains aren’t something to avoid. They reduce the risk of heart disease, diabetes, and cancer. And they reduce the risk of premature death. We should be eating more whole grains, not less.

However, the authors did point out that this study has some weaknesses:

  • It is an association study, which does not prove cause and effect.
  • Study participants who consumed more whole grains also tended to consume more fruits and vegetables – and less red meat, sodas, and highly processed foods.

However, I would argue the second point is a strength, not a weakness. We need to give up the idea that certain foods or food groups are “heroes” or “villains”. We know that primarily plant-based diets like the Mediterranean and DASH diets are incredibly healthy. Does it really matter how much of those health benefits come from whole grains and how much comes from fruits and vegetables?

The Bottom Line

Dr. Strangelove and low-carb enthusiasts have been telling us we should avoid all grains, including whole grains. Is that good advice?

If Dr. Strangelove and his colleagues were correct, consumption of whole grains should increase the risk of deaths due to the top two killer diseases, heart disease and cancer. Furthermore, because heart disease and cancer account for 44% of all deaths in this country, whole grain consumption should also increase the risk of death due to all causes.

A recent study showed the exact opposite. The study showed:

When the highest whole grain intake (5 servings/day) was compared with the lowest whole grain intake (0 servings/day), whole grain consumption reduced the risk of death from:

  • Heart disease by 18%.
  • Cancer by 12%.
  • All causes by 16%.

Furthermore, the effect of whole grains on mortality showed an inverse dose response. Simply put, the more whole grains people consumed, the lower the risk of deaths from heart disease, cancer, and all causes.

However, the dose response was not linear. Simply going from 0 servings of whole grains to one serving of whole grains reduced the risk of death from.

  • Heart disease by 9%.
  • Cancer by 5%.
  • All causes by 7%.

The authors concluded: “Whole grain consumption was inversely associated with mortality in a dose-response manner, and the association with cardiovascular mortality was particularly strong and robust. These observations endorse current dietary guidelines that recommend increasing whole grain intake to replace refined grains to facilitate long-term health and to help prevent premature death.”

The authors went on to say: “Low-carbohydrate diets that ignore the health benefits of whole grain foods should be adopted with caution because they have been linked to higher cardiovascular risk and mortality.”

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.

Omega 3 Supplementation And Heart Disease Risk

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How Can You Reduce Your Risk Of Heart Disease?

fish and fish oilI understand your confusion. One month the headlines say that omega 3 supplementation reduces the risk of heart disease. The next month headlines claim that omega 3 supplements are worthless. What is the truth about omega 3 supplementation and heart disease risk?

Let me start by sharing the two of the most recent studies on the topic. They are both very large, well designed studies. However, the reason I selected these two studies is that they approached the relationship between omega 3 supplementation and heart disease risk in very different ways but came to the same conclusion.

The first study (Y Hu et al, Journal of the American Heart Association, Volume 8, Issue 19, 1 October 2019) was a meta-analysis of 13 randomized controlled clinical studies looking at the relationship between omega 3 supplementation and heart disease risk.

The second study (Z-H Li et al, British Medical Journal, BMJ2020;368:m456) looked at the association between habitual omega 3 supplementation and heart disease risk.

Each of these studies had strengths and weaknesses, but they complemented each other. The weaknesses of one study were the strengths of the other study.

How Were The Studies Done?

Clinical StudyStudy #1: The 13 studies included in the meta-analysis had a total of 127,477 participants (mean age 64, 60% male, mostly overweight) who were given either an omega-3 supplement or a placebo.

  • 40% of the participants had diabetes.
  • 72% of the participants were on cholesterol lowering drugs and a variety of other medications.
  • Participants were followed for between 3 and 7.4 years (average follow-up period was 5 years).
  • The dose of omega 3s ranged between 376 and 4,000 mg/day.

The major strengths of this study were:

  • All 13 studies included in the meta-analysis were randomized, placebo controlled clinical trials.
  • The meta-analysis had a very large number of participants (nearly 130,000), so it was possible to accurately measure even small effects of omega 3 supplementation on heart disease risk.

The major weaknesses of this study were:

  • Most of the participants were already on multiple drugs that provided many of the same benefits as omega 3s, so it was impossible to assess the full effect of omega 3 supplementation on heart disease risk.
  • The duration of the clinical trials included in this meta-analysis was short compared to the decades required for heart disease to develop.
  • Most of the participants already had heart disease or were at high risk of developing heart disease. The people in these studies were not representative of the general population.

Study #2: The data for this study were obtained from the UK Biobank study which enrolled 427,678 participants (mean age 56, 45% male) from 22 medical centers across England, Scotland, and Wales. None of the participants had been diagnosed with heart disease or cancer at the time of enrollment.

At enrollment the participants filled out a detailed online questionnaire concerning their lifestyle, diet, diseases, medications, and supplement use. Among the questions was whether they habitually used fish oil supplements (Yes or No).

  • The participants were enrolled between 2006 and 2010 and followed for an average of 9 years.
  • 31% of the participants were already taking omega 3 supplements on a regular basis at the time they enrolled in the study. This was the omega 3 supplementation group. The remaining 69% was the control group.
  • Only 10% of the participants were taking statin drugs or aspirin, probably because none of them had been diagnosed with heart disease.
  • Around 10% of the participants had high blood pressure and were taking blood pressure medications.
  • Most of the participants were slightly overweight but only 4% had diabetes.

The main strengths of this study were:

  • Very few of the participants were on medications. That means that medications did not interfere with the effect of omega 3 supplementation.
  • The participants were already using omega 3 supplements at the time of enrollment and were followed for an additional 9 years. That means that the duration of omega 3 supplement use was much longer than in the first study.
  • The participants were healthy and free of heart disease at the beginning of the study. That means that the results of this study focused more on prevention than on treatment. It also means the results are more applicable to the general population.

The main weakness of this study was:

  • It was an association study, which cannot prove cause and effect. In contrast, the first study was based on randomized, placebo controlled clinical trials, which can prove cause and effect.

In short, the weaknesses of the first study were strengths of the second study and vice-versa.

Omega 3 Supplementation And Heart Disease Risk

strong heartStudy #1: The results from the meta-analysis of randomized, placebo-controlled clinical trials were that omega 3 supplementation:

  • Reduced heart attacks by 12%.
  • Reduced overall heart disease risk by 7%.
  • Reduced deaths from heart disease by 8%.
  • Because of the large number of participants included in the meta-analysis, all these reductions were highly significant.
  • The risk reduction was linearly related to the dose of omega-3s, but the study did not allow estimation of an optimal omega-3 dose.

The authors concluded: “Marine [fish oil] omega-3 supplementation lowers risk for heart attack, overall heart disease risk, and heart disease death…Risk reductions appear to be linearly related to marine omega-3 dose.”

Study #2: This study showed that regular use of omega-3 supplements:

  • Reduced deaths from all causes by 13%.
  • Reduced deaths from heart attacks by 20%.
  • Reduced deaths from all types of heart disease by 16%.
  • Because of the large number of participants, all these reductions were highly significant.
  • This study did not collect data on omega-3 dose, so the study did not allow estimation of an optimal omega-3 dose.

The authors concluded: “Habitual use of fish oil seems to be associated with a lower risk of all cause mortality and heart disease mortality…,supporting their use for the prevention of mortality from all causes and heart disease. Future studies are needed to examine the extent to which the dose of fish oil supplements influences the ability to achieve a clinically meaningful effect.”

While these studies did not provide information on the optimal omega 3 dose, a previous study concluded that an omega-3 intake of 835 mg/day or higher is needed to achieve clinically meaningful reductions in heart disease risk.

How Can You Reduce Your Risk Of Heart Disease?

Heart Healthy DietThese two studies support the value of omega 3 supplementation for reducing heart disease risk. However, while risk reductions were highly significant, the magnitude of risk reduction was relatively small. That means we should think of omega-3 supplementation as part of a holistic approach to reducing our health disease risk. It is just one piece of the puzzle.

With that in mind, here is what the American Heart Association recommends for reducing your risk of heart disease:

  • If you smoke, stop.
  • Choose good nutrition.
    • Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, nontropical vegetable oils, and nuts.
    • Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.
  • Reduce high blood cholesterol and triglycerides.
    • Reduce your intake of saturated fat, trans fat and cholesterol and get moving.
    • If diet and physical activity don’t get those numbers under control, then medication may be the next step.
  • Lower High Blood Pressure.
  • Be physically active every day.Heart Healthy Exercise
    • Aim for at least 150 minutes per week of moderate-intensity physical activity per week.
  • Aim for a healthy weight.
  • Manage diabetes.
  • Reduce stress.
  • Limit alcohol.

Add in omega-3 supplementation to these recommendations and you have a winning combination.

The Bottom Line

Two major studies have recently been published on the relationship between omega 3 supplementation and heart disease. I felt it was important to evaluate these studies together because:

  • They are both very large, well designed studies.
  • They approached the relationship between omega 3 supplementation and heart disease risk in very different ways but came to the same conclusion.
  • They complemented each other. The weaknesses of one study were the strengths of the other study.

These studies showed that omega 3 supplementation:

  • Reduced heart attacks by 12-20%.
  • Reduced overall heart disease risk by 7%.
  • Reduced deaths from heart disease by 8-16%.
  • Reduced deaths from all causes by 13%

While these studies did not provide information on the optimal omega 3 dose, a previous study concluded that an omega-3 intake of 835 mg/day or higher is needed to achieve clinically meaningful reductions in heart disease risk.

For more details and the American Heart Association recommendations on what else you can do to reduce your risk of heart disease, 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.

Could A Probiotic Supplement Make You Healthier?

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What Is The Truth About Our Microbiome?

Myth BusterOur gut bacteria, often referred to as our microbiome, are a “hot” topic in today’s world. They have been in the news a lot in recent years. If you believe the headlines, the right gut bacteria can make you smarter, healthier, and cure what ails you. They appear to have almost mystical powers. Could a probiotic supplement make you healthier?

How much of this is true and how much is pure speculation? It’s hard to say. Our microbiome is incredibly complex. To make matters more confusing, the terminology used to classify our gut bacteria into groups is not consistent. It varies from study to study.

Perhaps it is time to take an unbiased look at the data and separate fact from speculation.

Could A Probiotic Supplement Make You Healthier?

Probiotic SupplementTo answer the question of whether a probiotic supplement could make you healthier, we need to differentiate between what we know is true and what we think might be true. Let’s start with what we know for certain:

  • Our gut bacteria are affected by diet. People consuming a primarily plant-based diet have different populations of gut bacteria than people consuming a primarily meat-based diet.
    • The populations of gut bacteria found in people consuming a plant-based diet are associated with better health outcomes, but associations have their limitations as discussed below.
  • Our gut bacteria are affected by exercise.
    • It’s not clear whether it is the exercise or the fitness (increased muscle mass, decreased fat mass, improved metabolism) associated with exercise that is responsible for this effect.

Most of the other claims for the effects of gut bacteria on our health are based on associations. However, associations do not prove cause and effect. For example:

  • Certain populations of gut bacteria are associated with obesity.
    • Do our gut bacteria make us obese, or does obesity affect our gut bacteria? There is evidence to support both viewpoints.
  • Certain populations of gut bacteria are associated with better mental health.
    • Do gut bacteria influence mental health, or does the stress associated with poor mental health influence our gut bacteria? Again, there is evidence to support both viewpoints.
  • Certain populations of gut bacteria are associated with better health outcomes (reduction in diseases like heart disease, diabetes, and high blood pressure).
    • Here the question is a little different. In general, the populations of gut bacteria associated with disease reduction are produced by a healthy diet, exercise, and weight control. In this case, the question becomes: Is it the gut bacteria that caused disease reduction, or is it diet, exercise, and weight control that caused disease reduction?

To better understand these points, let’s look at four recently published studies. After reviewing those studies, I will come back to the question of whether a probiotic supplement might decrease our disease risk.

Is Our Microbiome Better Than Our Genes For Predicting Disease?

Predict DiseaseThis study (T. Tierney et al, bioRxiv, 2020) reviewed 47 studies that analyzed people’s microbiome (their gut bacteria) and their genes and asked which was better at predicting their risk of various diseases. The study focused on 13 diseases that are considered “complex” because they are caused by both genetic and environmental factors such as diet and exercise. Examples include diabetes, high blood pressure, digestive disorders, asthma, Parkinson’s disease, and schizophrenia.

The study found that our microbiome was a better predictor of these diseases than our genes. This finding is not surprising. Our microbiome is heavily influenced by diet and other environmental factors. Our DNA sequence is not.

This study supports previous studies in suggesting that our microbiome is a better predictor of most diseases than our DNA sequence. The exception would be diseases that are clearly caused by gene mutations, such as sickle cell disease.

Does this mean our microbiome is directly influencing these diseases, or is it merely serving as a marker for diet and other environmental factors that are influencing these diseases? Nobody knows.

Does The Mediterranean Diet Support Gut Bacteria Linked To Healthy Aging?

Mediterranean dietThis study ( TS Ghosh et al, Gut, 17 February 2020) divided people aged 65-79 into two groups. One group consumed a Mediterranean diet rich in fruits, vegetables, nuts, legumes, olive oil, and fish and low in red meat and saturated fat. The other group consumed a typical western diet. After a year on the diets the gut bacteria in the microbiomes of the two groups was analyzed.

The study found that the group consuming the Mediterranean diet had an increase in gut bacteria associated with healthy aging, reduced inflammation, and reduced frailty.

The title of the paper describing this study was “Mediterranean diet intervention alters the gut microbiome in older people, reducing frailty and improving health status”. But is that true?

There is already good evidence that the Mediterranean diet improves health status. Is it the gut bacteria supported by the Mediterranean diet that were responsible for healthy aging, or were other aspects of the Mediterranean diet responsible for healthy aging? Nobody knows.

Are Low Fat Diets Healthy Because Of Their Effect On Our Microbiome?

Heart Healthy DietThis study (Y Wang et al, Gut Microbes, 21 January 2020) put participants on a low fat diet (20% fat and 66% carbohydrates), a moderate fat diet (30% fat and 56% carbohydrate) or a high fat diet (40% fat, 46% carbohydrates). To assure the accuracy of the diets, participants were provided with all foods and beverages they consumed. After 6 months on the three diets, the gut bacteria of each group were analyzed.

Note: Because all food and beverages were provided, none of the diets included sodas, added sugar, refined flour, saturated fats, or highly processed food. In short, the diets were very different than the typical low fat or low carb diets consumed by the average American.

This study found that participants consuming the high fat, low carb diet had gut bacteria associated with increased risk of heart disease and diabetes. In contrast, the low fat, high carbohydrate diet group had gut bacteria associated with decreased risk of heart disease and diabetes.

To understand this study, you need to reevaluate what you may have learned from Dr. Strangelove’s health blog. It is true that low fat diets in which fat has been replaced with sugar, refined flour, and highly processed low-fat foods are unhealthy. But that’s not what happened in this study.

Remember that all the food and drink the participants consumed was selected by dietitians.

When you replace the fat with whole foods – fresh fruits and vegetables, whole grains, nuts, and legumes, as was done in this study, you end up with a very healthy diet.

The authors talked about the importance of the “diet-gut axis” for reducing the risk of heart disease and diabetes. However, is it the gut bacteria that influenced the risk of heart disease and diabetes, or is it the diets themselves that influenced disease risk? Nobody knows.

Can Gut Bacteria Reduce Heart Disease Risk?

MicrobiomeThis study (Y Heianza et al, Journal of The American College Of Cardiology, 75: 763-772, 2019) focused on the interactions between diet, gut bacteria, and a metabolite called TMAO (trimethylamine N-oxide).

Here is what we know for certain:

  • L-carnitine (found in high levels in red meat) can be converted to TMA (trimethylamine) by gut bacteria and then to TMAO in the liver.
  • The gut bacteria of meat eaters are very efficient at converting L-carnitine to TMA. Thus, meat eaters tend to have high levels of TMAO in their blood.
  • The gut bacteria of vegans and vegetarians are very inefficient at converting L-carnitine to TMA. Thus, people consuming a primarily plant-based diet tend to have low TMAO levels in their blood.

Here is what we are uncertain about:

  • High TMAO levels are associated with increased heart disease risk. However, there is no direct evidence that TMAO causes heart disease.

What made this study unique is that it measured TMAO levels in the study participants at their entrance into the study and again 10 years later. The study found:

  • Participants with the greatest increase in TMAO levels over the 10 years had a 67% increased risk of heart disease compared to participants whose TMAO levels remained constant.
  • Participants consuming a healthy, primarily plant-based diet had little or no increase in TMAO levels over 10 years. It was the participants consuming an unhealthy diet who had significant increases in their TMAO levels.

This study strengthens the association between TMAO levels and heart disease risk. Because gut bacteria are required to produce TMAO, it also strengthens the association between gut bacteria and heart disease risk. However, is it the high TMAO levels that increased heart disease risk or is it the unhealthy diet that increased heart disease risk? Nobody knows.

What Is The Truth About Our Microbiome?

MicrobiomeBy now you have probably noticed a common theme that runs through all four studies. This is also true of most published studies on our microbiome.

  • We have good evidence that whole food, primarily plant-based diets lead to improved long-term health outcomes.
  • We also have good evidence that whole food, primarily plant-based diets influence the populations of gut bacteria found in our microbiome.
  • We know the populations of gut bacteria supported by primarily plant-based diets are associated with improved health outcomes.
  • We don’t really know whether it is the gut bacteria or the diets that are responsible for the improved health outcomes.

Don’t misunderstand me. I am not a microbiome skeptic. I think we have enough evidence to say that our gut bacteria are likely to have an important effect on our health. However, to claim that gut bacteria play a primary role in influencing our health would be pure speculation at this point.

A Cautionary Tale

HDL CHolesterolWhy do I make this point? It’s because I suspect that some in the supplement industry will be tempted to make probiotic supplements and claim they contain bacteria “known” to reduce the risk of heart disease, diabetes, or cancer. You wouldn’t need to change your diet. All you would need to do to improve your health would be to take their probiotic supplement.

Lest you be taken in by such future claims, let me share a cautionary tale.

High HDL cholesterol levels are associated with a reduced risk of heart disease. Exercise and weight loss increase HDL levels. However, those require work. They aren’t easy. So, pharmaceutical companies were constantly looking for ways to raise HDL levels without the hard work.

A few years ago, a pharmaceutical company discovered a drug that increased HDL levels. They thought they had discovered a wonder drug that would bring in billions of dollars. People wouldn’t need to exercise. They wouldn’t need to lose weight. All they would need to do would be to take their drug. HDL levels would go up and heart disease risk would go down.

However, when they tested their drug in a major clinical trial, it didn’t move the needle. HDL levels went up, but heart disease risk stayed the same. It turns out it was the exercise and weight loss that decreased heart disease risk, not the increase in HDL levels.

My message is simple. Even if our gut bacteria are found to play a major role in mediating the effect of diet on health outcomes, don’t assume we can take a probiotic and forget about the role of diet and exercise. Good health starts with a whole food, primarily plant-based diet and a healthy lifestyle.

The Bottom Line

Our gut bacteria, often referred to as our microbiome, are “hot”. If you believe the headlines, the right gut bacteria can make you smarter, healthier, and cure what ails you. How much of this is true and how much is pure speculation? In this article I reviewed four recent studies on diet, gut bacteria, and health outcomes. I took an unbiased look at the data and separated fact from speculation.

There was a common theme that ran through all four studies. This is also true of most published studies on our microbiome.

  • We have good evidence that whole food, primarily plant-based diets lead to improved long-term health outcomes.
  • We also have good evidence that whole food, primarily plant-based diets influence the populations of bacteria found in our gut, also known as our microbiome.
  • We know the populations of gut bacteria supported by primarily plant-based diets are associated with improved health outcomes.
  • We don’t really know whether it is the gut bacteria or the diets that are responsible for the improved health outcomes.

Don’t misunderstand me. I am not a microbiome skeptic. I think we have enough evidence to say that our gut bacteria are likely to have an important effect on our health. However, to claim that gut bacteria play a primary role in influencing our health would be pure speculation at this point.

Why do I make this point? It’s because I suspect that some in the supplement industry will be tempted to make probiotic supplements and claim they contain bacteria “known” to reduce the risk of heart disease, diabetes, or cancer. You wouldn’t need to change your diet. All you would need to do to improve your health would be to take their probiotic supplement.

My message is simple. Even if our gut bacteria are found to play a major role in mediating the effect of diet on our health outcomes, don’t assume we can take a probiotic and forget about the role of diet and exercise. Good health starts with a whole food, primarily plant-based diet and a healthy lifestyle.

For more details, read the article above. You may be particularly interested in the cautionary tale I shared about HDL and heart disease risk.

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