heart health

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.

Are Nuts Good For Your Heart?

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Which Nuts Are Best?

Last week I shared an important study about the benefits of replacing some of the animal protein in your diet with plant protein from whole grains. In case you have forgotten, the study showed replacing just 15 grams of the animal protein in your diet with an equivalent amount of protein from whole grains significantly decreased the risk of premature death from cardiovascular disease, stroke, and from all causes.

This was an important study because whole grains have been maligned in recent years. Low carb diets, keto diets, paleo diets, and low-lectin diets all recommend cutting whole grains out of your diet. Dr. Strangelove and his friends have been telling us to avoid whole grains, and too many Americans have been doing just that.

The study I shared last week reminds us that whole grains are good for our hearts. They are a great source of antioxidants, B vitamins, minerals, and phytonutrients. More importantly, they contain a unique type of fiber called resistant starch that supports the growth of heart-healthy gut bacteria. There are a few other foods that are a good source of resistant starch, but they are also on Dr. Strangelove’s “naughty list” of foods to avoid.

Unfortunately, you might have come away from last week’s article thinking that other plant protein sources, like beans, legumes, nuts, and seeds, weren’t important for reducing your risk of heart disease. However, the fact that they didn’t reduce the risk of premature death from heart disease in that study was likely an artifact of the way the study was designed.

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 either beans and legumes or nuts and seeds to provide a statistically valid answer to that question.

To correct any misconceptions from last week’s article I thought it might be valuable to review a study (M Guasch-Ferré et al, Journal Of The American Journal Of Cardiology, 70: 2519-2532) from a few years ago that looked at the effect of nut consumption on the risk of heart disease.

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 169,310 women and 41,526 men and followed them for an average of 32 years. All the participants were free of heart disease and cancer at the time they were enrolled. The design of these studies was extraordinary.

  • A detailed food frequency questionnaire was administered every 4 years. This allowed the investigators to calculate cumulative averages of all dietary variables, including nuts. This assured that the effects of nut consumption and diet represented the participant’s average diet over the 32-year duration of the study, not just their diet when they entered 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 heart disease for each participant during the study. More importantly, 32 years is long enough to measure the onset of diseases like heart disease, which requires decades to develop.
  • The primary endpoint of the study was “cardiovascular disease”, which the investigators defined as fatal and non-fatal heart attacks, fatal and non-fatal strokes, and deaths from all types of heart disease. During this study, 14,136 participants developed cardiovascular disease. This was a large enough number for a detailed statistical analysis of the data.
  • Secondary endpoints were heart disease (fatal and non-fatal heart attacks) and stroke (fatal and non-fatal strokes).

Are Nuts Good For Your Heart?

strong heartWhen the authors compared people who consumed 5 or more one ounce servings of nuts per week with people who never or almost never consumed nuts, they found that nut consumption decreased:

  • Cardiovascular disease by 14%.
  • Heart attacks by 20%.
  • Strokes by a non-significant 2%.

This part of the study merely confirms what other studies have shown. What makes this study unique is that it identifies the relative heart health benefits of different kinds of nuts.

Which Nuts Are Best?

Nuts are an excellent source of vitamins, minerals, phytonutrients, and fiber. But what makes them particularly heart healthy is the healthy fats they provide.

  • Peanuts (which are actually legumes rather than true nuts) are rich in monounsaturated fats.
  • Tree nuts in general are an excellent source of polyunsaturated fats.

    Walnuts
  • Walnuts are particularly rich in omega-3 polyunsaturated fats.

When they looked at individual nuts:

  • Consuming a serving of peanuts (35 peanuts) 2 or more times per week decreased:
    • Cardiovascular disease by 13%.
    • Heart attacks by 15%.
    • Stroke by 10%.
    • Peanut butter had no effect on cardiovascular outcomes, probably because many commercial brands of peanut butter add saturated fats to reduce separation of the oil and make their product creamier.
  • Consuming a serving of tree nuts (12-15 nuts) 2 or more times per week decreased:
    • Cardiovascular disease by 15%.
    • Heart attacks by 23%.
  • Consuming a serving of walnuts (14 walnut halves) one or more times per week decreased:
    • Cardiovascular disease by 19%.
    • Heart attacks by 21%.
    • Stroke by 17%.

In case you missed it, walnuts were the superstars of the nut family. One serving/week of walnuts was more effective than two or more servings/week of peanuts or other tree nuts at reducing the risk of heart attacks, stroke, and overall cardiovascular disease. This is probably because walnuts are a particularly good source of omega-3 fats.

[Professor’s note: I include a serving of walnuts with my breakfast every morning.]

The authors concluded: “Findings from 3 large prospective cohort studies indicate that frequent intake of nuts, tree nuts, peanuts, and walnuts was associated with a lower risk of cardiovascular disease, independently from other cardiovascular risk, lifestyle, and dietary factors. Our findings support recommendations of increasing the intake of a variety of nuts as part of healthy dietary patterns to reduce the risk of chronic diseases in the general population.”

What Does This Study Mean For You?

Questioning WomanI have consistently shared the evidence that primarily plant-based diets are associated with the best long-term health outcomes, especially when we look at chronic diseases like heart disease, diabetes, and cancer.

I have also consistently shared the message that “We have 5 food groups for a reason”. All 5 food groups are part of a healthy diet.

Unfortunately, Dr. Strangelove and his friends have been telling us that whole grains are bad for us. We should eliminate them from our diet. And too many Americans have been following that advice. That’s why last week’s “Health Tips From the Professor” article reviewed the evidence for heart health benefits from whole grain consumption.

The situation with nuts and seeds is a little different. Most people recognize them as healthy. They just don’t eat enough of them. That’s why this week’s article emphasized the heart health benefits from nut consumption. Here is the take home message I hope you get from this article:

  • Two or more servings/week of peanuts or tree nuts significantly reduces your risk of heart attack, stroke, and other cardiovascular diseases.
  • Walnuts are the superstars of the nut family. One serving/week of walnuts (14 walnut halves) was more effective at reducing the risk of heart attack, stroke, and other cardiovascular diseases than two or more servings/week of the other nuts.
  • This study was based on unprocessed nuts. Nuts coated with salt, sugar, or chocolate probably don’t qualify as heart healthy.
  • Processed foods made from nuts also may not be heart healthy. For example, peanut butter had no effect at decreasing heart disease risk in this study.

Finally, in closing I want to revisit my statement that “We have 5 food groups for a reason”.

  • The studies I shared this week and last week show that whole grains and nuts are important components of a heart healthy diet. But it doesn’t stop there.
  • All plant food groups are part of a heart healthy diet. In previous issues of “Health Tips From the Professor” I have shared studies showing beans, fruits, and vegetables are all important components of a heart healthy diet.
  • I have also shared recent studies showing that adding small amounts of eggs and dairy may make a vegetarian diet more heart healthy.
  • Finally, I have shared a study showing that small amounts of red meat can be heart healthy in the context of a primarily plant-based diet such as the Mediterranean diet.

Of course, we are talking about whole food diets. If you include sodas and highly processed foods in the diet, all bets are off.

The Bottom Line

I have consistently shared the evidence that primarily plant-based diets are associated with the best long-term health outcomes, especially when we look at chronic diseases like heart disease, diabetes, and cancer.

I have also consistently shared the message that “We have 5 food groups for a reason”. All 5 food groups are part of a healthy diet.

Unfortunately, Dr. Strangelove and his friends have been telling us that whole grains are bad for us. We should eliminate them from our diet. And too many Americans have been following that advice. That’s why last week’s “Health Tips From the Professor” article reviewed the evidence for heart health benefits from whole grain consumption.

The situation with nuts and seeds is a little different. Most people recognize them as healthy. They just don’t eat enough of them. That’s why this week’s article emphasized the heart health benefits of nut consumption. Here is the take home message I hope you get from this article:

  • Two or more servings/week of peanuts or tree nuts significantly reduces your risk of heart attack, stroke, and other cardiovascular diseases.
  • Walnuts are the superstars of the nut family. One serving/week of walnuts (14 walnut halves) was more effective at reducing the risk of heart attack, stroke, and other cardiovascular diseases than two or more servings/week of the other nuts.
  • This study was based on unprocessed nuts. Nuts coated with salt, sugar, or chocolate probably don’t qualify as heart healthy.
  • Processed foods made from nuts also may not be heart healthy. For example, peanut butter had no effect at decreasing heart disease risk in this study.

Finally, in closing I want to revisit my statement that “We have 5 food groups for a reason”.

  • The studies I shared this week and last week show that whole grains and nuts are important components of a heart healthy diet. But it doesn’t stop there.
  • All plant food groups are part of a heart healthy diet. In previous issues of “Health Tips From the Professor” I have shared studies showing beans, fruits, and vegetables are all important components of a heart healthy diet.
  • I have also shared recent studies showing that adding small amounts of eggs and dairy may make a vegetarian diet more heart healthy.
  • Finally, I have shared a study showing that small amounts of red meat can be heart healthy in the context of a primarily plant-based diet such as the Mediterranean diet.

Of course, we are talking about whole food diets. If you include sodas and highly processed foods in the diet, all bets are off.

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.

Is The Paleo Diet Bad For Your Heart?

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Is The Paleo Diet Bad For Your Gut?

the paleo dietThere is a lot to like about the Paleo diet:

·       It is a whole food diet. Any diet that eliminates sodas, junk foods, and highly processed foods is an improvement over the American diet.

·       It includes lots of vegetables and some fruits.

·       It helps you lose weight, and any diet that results in weight loss improves your blood work – things like cholesterol, triglycerides, blood sugar control and more.

However, there are concerns the Paleo diet may not be healthy long term.

·       In part, that is because the diet is high in meat, red meat, and saturated fat.

·       Equally important, however, is what the diet eliminates – namely whole grains, legumes (beans), and dairy.

Those of you who have read my book, “Slaying The Food Myths”, know that I say: “We have 5 food groups for a reason”. This is particularly true for the plant food groups. That’s because each plant food group provides a unique blend of:

·       Vitamins and minerals. Those can be replaced with good multivitamin/multimineral supplement.

·       Phytonutrients. You can only get the full complement of health-promoting phytonutrients from a variety of foods from all 5 food groups.

·       Fiber. There are many kinds of fiber and they each play different roles in our intestine. You can only get all the health-promoting varieties of fiber by consuming fruits, vegetables, whole grains and legumes.

·       Gut bacteria. What we call fiber, our gut bacteria call food. Each of the plant food groups supports different populations of friendly gut bacteria.

Based on this reasoning, one might suspect that the Paleo diet might alter our gut bacteria in ways that could be bad for our health. Until recently, this sort of reasoning was just a theoretical concern. That’s because:

1)    We knew far too little about the health effects of different populations of bacteria. This is rapidly changing. Several recent studies have systematically investigated the connection between gut bacteria and health outcomes.

2)    We knew our diet influenced the bacteria populations found in our gut, but we had no understanding of how these changes might influence our health. This too is changing. The study (A Genoni et al, European Journal of Nutrition, https://doi.org/10.1007/s00394-019-02036-y) I discuss this week is an excellent example of recent studies linking diet, gut bacteria, and risk factors for disease.

How Was The Study Done?

can you believe clinical studies doctorThis study recruited 91 participants from Australia and New Zealand. It was a very well designed study in that:

·       The Paleo diet group (44 participants) was recruited based on self-proclaimed adherence to the Paleo diet (< 1 serving/day of grains and dairy products) for one year or more. This is important because short term effects of switching to a new diet are confounded by weight loss and other factors.

o   After analyzing the diets of the Paleo group, the investigators found it necessary to subdivide the group into Strict Paleo (< 1 serving/day of grains and dairy products) and Pseudo-Paleo (> 1 serving/day of grains and dairy).

·       The control group (47 participants) was recruited based on self-proclaimed adherence to a “healthy diet” for 1 year or more with no change in body weight (A healthy diet was defined as a whole food diet containing a variety of foods from all 5 food groups). This is important because far too many studies compare the diet they are promoting to an unhealthy diet with a lot of sugar and highly processed junk foods. These studies provide little useful information because almost anything is better than an unhealthy diet.

·       The participants completed a diet survey based on the frequency of consumption of various foods during the previous year. However, because diet surveys based on the recollection of participants can be inaccurate, the investigators used two rigorous tests to validate the accuracy of those diet surveys.

o   The first was a 3-day weighed dietary record (WDR). Simply put, this means that participants weighed and recorded all foods and beverages before they were eaten for 3 days. Two of those days were weekdays, and one was a weekend day.

o   Secondly, the investigators used blood, urine, and metabolic measures to independently determine protein and energy intake of each participant. Participants who were identified by these means as under reporting both protein and energy were considered unreliable dietary reporters and were excluded from the analysis.

o   It is very rare to find a study that goes to this length to validate the accuracy of the dietary data used in their analysis.

The participants also provided blood, urine and stool samples and completed a physical activity assessment.

What Were The Differences Between The Paleo Diet And The Healthy Control Diet?

Paleo FoodsOnly the Strict Paleo Diet group was faithfully following the Paleo diet. In addition, most of the results with the Pseudo Paleo Diet Group were intermediate between the other two diets. Therefore, to simplify my discussion of this study I will only compare the Strict Paleo Diet group, which I refer to as the Paleo Diet group, with the Healthy Diet control group.

The Paleo diet emphasizes fresh vegetables, especially green leafy vegetables, and discourages grains. Thus, it is no surprise that:

·       The Paleo Diet group ate 74% more vegetables and 3 times more leafy green vegetables than the Healthy Diet group.

·       The Paleo Diet group ate only 3% of the grains and 3% of the whole grains compared to the Healthy Diet group.

The Paleo diet encourages consumption of meat and eggs and discourages consumption of dairy and plant proteins. Thus, it is not surprising that:

·       The Paleo Diet group ate 3 times more red meat and 5 times more eggs than the Healthy Diet group.

·       The Paleo Diet group ate 10% of dairy foods compared to the Healthy Diet group.

·       The Paleo Diet group consumed two times more saturated fat and cholesterol than the Healthy Diet group.

The most interesting comparison between the two diets was the following:

·       Intake of total fiber, insoluble fiber, and soluble fiber was comparable on the two diets.

·       However, intake of resistant starch was 50% lower in the Paleo Diet group. This is significant because:

o   Resistant starch is a type of fiber found primarily in whole grains, legumes, potatoes, and yams (Potatoes and yams are also dietary “no nos” on most low-carb diets).

o   Resistant starch is an especially good food for certain species of healthy gut bacteria.

Is The Paleo Diet Bad For Your Gut?

Bas BacteriaBecause resistant starch affects gut bacteria, the study next looked at the effect of the two diets on the populations of gut bacteria. This is where the story starts to get interesting. When they looked at different groups of gut bacteria, they discovered that:

·       Bifidobacteria were much more abundant in the Healthy Diet group than in the Paleo Diet group, and the amount of Bifidobacteria in the gut was directly proportional to the amount of whole grains in the diet.

o   This is important because previous studies have suggested Bifidobacteria help maintain intestinal barrier integrity and protect against irritable bowel syndrome and obesity.

·       Roseburia were also much more abundant in the Healthy Diet group and proportional to the amount of whole grains in the diet.

o   This is important because previous studies have suggested Roseburia protect against inflammatory bowel diseases like Crohn’s disease and ulcerative colitis.

·       Hungatella were much more abundant in the Paleo Diet group and were inversely proportional to the amount of whole grains in the diet.

o   This is important because Hungatella metabolize carnitine and choline, which are found in meats (especially red meats), egg yolks, and high fat dairy, into a compound called trimethylamine or TMA. TMA is then further metabolized in the liver to trimethylamine-N-oxide, or TMAO.

o   TMAO is a bad player. It is positively associated with heart disease, stroke, kidney disease, diabetes, and Alzheimer’s disease. However, the evidence is strongest for heart disease. TMAO has been called an independent risk factor for cardiovascular death.

Because of this, the study looked at TMAO levels in the blood of the two diet groups. These results were concerning:

·       TMAO levels were 2.5-fold higher in the Paleo Diet group than in the Healthy Diet group.

·       As might be expected, TMAO levels were positively correlated with red meat intake and inversely proportional to whole grain intake.

Is The Paleo Diet Bad For Your Heart?

heart diseaseWhen you put all the evidence together you have a compelling argument that the Paleo diet is likely to increase the risk of heart disease. Let me summarize the data briefly:

1)    The Paleo diet discourages the consumption of whole grains.

2)    Whole grains are a major source of a dietary fiber called resistant starch.

3)    Because the Paleo diet is low in resistant starch, it causes a decrease in two healthy types of gut bacteria and an increase in a type of gut bacteria called Hungatella.

4)    Hungatella metabolize compounds found in meat, eggs, and dairy to a precursor of a chemical called TMAO. This study showed that TMAO levels were 2.4-fold higher in people consuming a Paleo diet.

5)    TMAO is associated with coronary artery disease and is considered an independent risk factor for cardiovascular death.

The authors of the study concluded: “Although the Paleo diet is promoted for improved gut health, results indicate long-term adherence is associated with different gut microbiota and increased TMAO. A variety of fiber components, including whole grain sources, may be required to maintain gut and cardiovascular health.”

Of course, studies like this are looking at associations. They are not definitive. What we need are long term studies looking at the effect of the Paleo diet on heart disease outcomes like heart attack and stroke. Until we have these studies my advice is:

·       Don’t accept claims that the Paleo diet is heart healthy. There are no long-term clinical studies to back up that claim.

·       Be aware that the Paleo diet affects your gut bacteria in ways that may be bad for your heart.

The more we learn about our gut bacteria, the more we appreciate the importance of including all 5 food groups in our diet, especially all the plant food groups.

Are Low Carb Diets Healthy?

low carb dietThe Paleo diet is not the only diet that is high in red meat and low in whole grains. The same is true for virtually all the popular low-carb diets. There are studies showing other low-carb diets also alter gut bacteria and raise TMAO levels, so there is a similar concern that they may also increase the risk of heart disease.

This is in addition to concerns about the high saturated fat consumption which increases the risk of heart disease and red meat consumption, which may increase the risk of certain cancers.

Finally, there are no studies showing that any low-carb diet is healthy long term, even the Atkins diet, which has been around for more than 50 years. Until we have long-term studies about the health consequences of low-carb diets, my advice is similar to that for the Paleo diet.

·       Don’t accept claims that low-carb diets are healthy. There are no long-term clinical studies to back up that claim.

·       Be aware that low-carb diets affect your gut bacteria in ways that may be bad for your health.

The Bottom Line

A recent study looked at the effect of the Paleo diet on an important risk factor for heart disease. Here is a brief summary of the data:

1)    The Paleo diet discourages the consumption of whole grains.

2)    Whole grains are a major source of a dietary fiber called resistant starch.

3)    Because the Paleo diet is low in resistant starch, it causes a decrease in two healthy types of gut bacteria and an increase in a type of gut bacteria called Hungatella.

4)    Hungatella metabolize compounds found in meat, eggs, and dairy to a precursor of a chemical called TMAO. This study showed that TMAO levels were 2.4-fold higher in people consuming a Paleo diet.

5)    TMAO is associated with coronary artery disease and is considered an independent risk factor for cardiovascular death.

Of course, studies like this are looking at associations. They are not definitive. What we need are long term studies looking at the effect of the Paleo diet on heart disease outcomes – like heart attack and stroke. Until we have these studies my advice is:

·       Don’t accept claims that the Paleo diet is heart healthy. There are no long-term clinical studies to back up that claim.

·       Be aware that the Paleo diet affects your gut bacteria in ways that may be bad for your heart.

·       Virtually all the popular low-carb diets discourage consumption of whole grains, so my advice for them is the same as for the Paleo diet.

The more we learn about our gut bacteria, the more we appreciate the importance of including all 5 food groups in our diet, especially all the plant food groups.

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

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

Does An Apple A Day Keep Statins Away?

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The Latest On Diet And Heart Health

Author: Dr. Stephen Chaney

AppleIn a previous “Health Tips From the Professor” I talked about how difficult it has been to prove that statins significantly reduce the risk of heart attack or cardiovascular deaths in a low risk population group. Now let’s look at the other side of the coin – lifestyle change –and ask how effective lifestyle change is at reducing the risk of cardiovascular disease.

You’ve all heard the saying “An apple a day keeps the doctor away”. It dates back to Victorian England. It was the public health message of the day – much simpler and more concise than our current food guide plate.

A prominent British doctor and his research team recently decided to see how accurate that saying really was. But they took their study one step further. They compared the effectiveness of an apple a day versus a statin a day at reducing the risk of cardiovascular deaths (Briggs et al, British Medical Journal, 3013;347:f7267 doi: 10.1136/bmj.f7267).

The results of that comparison may surprise you.

Does An Apple A Day Keep Statins Away?

They used the data from the Cholesterol Treatment Trialist meta-analysis to estimate the effectiveness of statin drugs at reducing cardiovascular deaths. They used the data from the PRIME comparative risk assessment model to estimate the effectiveness of apple a day at reducing cardiovascular deaths.

They asked what would happen if each of them were the primary intervention for the entire British population over 50 who were not currently taking statin drugs (17.6 million people).

They assumed a 70% compliance rate for both interventions. In simple terms that means they assumed that 70% of the population would actually do what their doctors told them. (Patients must be more compliant in England than in the US).

The results were interesting. They estimated that:

  • Giving a statin drug each day to 17.6 million people would reduce the number of cardiovascular deaths by 9,400.
  • Giving an apple each day to the same 17.6 million people would reduce the number of cardiovascular deaths by 8,500 (not significantly different).

But when they looked at side effects and cost the two interventions were significantly different.

  • Giving a statin drug each day to 17.6 million people would also cause some significant side effects. The authors estimated that it would lead to:
    • 1,200 excess cases of severe muscle pain and weakness
    • 200 excess cases of rhabdomyolysis (muscle breakdown, which can lead to irreversible kidney failure)
    • 12,300 excess cases of diabetes
  • On the other hand, there are no known side effects to an apple a day.
  • The statin intervention would cost an estimated $295 million. In the case of apples, you would presumably be substituting a more healthy food for a less healthy food so there would be little or no net cost.

And the 70% compliance rate is probably wildly optimistic. Some experts have estimated that up to 50% of patients discontinue their statin medications within the first year because of side effects or cost.

Is There A Scientific Basis For Those Estimates?

Of course, we all know that the “apple a day…” saying was never meant to be taken literally. It was just a simple way of saying that a good diet will reduce the risk of disease.

It turns out that there was another major study on the effect of dietary fiber on reducing the risk of cardiovascular disease in the very same issue (Threapleton et al, British Medical Journal, 2013;347:f6879 doi: 10.1136/bmj.f6879). It was a meta-analysis that combined the data from 22 previously published studies.

This study showed:

  • For every 7 g/day increase in dietary fiber the risk of both heart attacks and cardiovascular disease decreases by 9% (7 grams of dietary fiber could come from one serving of whole grains plus one serving of beans or lentils or from two servings of fruits or vegetables).
  • For every 4g/day of fruit fiber (equivalent to one apple) the risk of heart attacks decreases by 8% and the risk of cardiovascular disease decreases by 4%.
  • The numbers are similar for every 4 g/day of vegetable fiber.

Another recent study showed that consumption of 75 g/day of dried apple (equivalent to two apples a day) lowered total cholesterol by 13% and LDL-cholesterol by 24% in post-menopausal women (Chai et al, J. Acad Nutr Diet, 112: 1158-1168, 2012). That’s comparable to the cholesterol reduction achieved with statin drugs.

The Bottom Line

  • If you have not previously had a heart attack and are at relatively low risk, something as simple as adding an apple a day (in place of less healthy foods) may just as effective as statin drugs at reducing your risk of cardiovascular death without the side effects and cost of the drugs.
  • This is not really new information. For years both the American Heart Association and the National Institutes of Health have recommended that Therapeutic Lifestyle Changes (weight loss, healthy diet and exercise) should be tried BEFORE drug treatment to reduce the risk of heart disease.
  • So if you want to avoid statins, tell your doctor that you are willing to make the needed lifestyle changes to reduce your risk of heart disease and stick with it. Lifestyle changes are hard, but clinical studies clearly show they can often be just as effective as drug therapy, without the cost and side effects.
  • Don’t misunderstand me. I’m not advocating avoiding statin drugs if they are absolutely necessary. If you have had a heart attack or are at high risk of heart disease, it is clear that statins can save lives. Even here I would recommend talking with your physician about incorporating therapeutic lifestyle change into your regimen. It may allow them to minimize the dose, and therefore the side effects, of the statin drugs.

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 Fatty Acids And Brain Health

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Is it How Much You Eat, or How Much You Keep?

Author: Dr. Stephen Chaney

 

Brain HealthWhy do some studies conclude that omega-3 fatty acids are essential for a strong mind, a strong heart and will wipe out inflammation – while other studies suggest that they are ineffective? The simple answer is that nobody really knows.

However, in the process of reviewing two recent studies on omega-3 fatty acids and brain health I made an interesting observation that offers a possible explanation for the discrepancies between studies. And if my hypothesis is correct, it suggests that the design of many of the previous studies with omega-3 fatty acids is faulty.

Omega-3 Fatty Acids And Brain Health

The first study (J.K. Virtanen et al, J Am Heart Assoc, 2013, 2:e000305 doi: 10.1161/JAHA.113.000305) looked at the effect of omega-3 fatty acids on brain function in older adults (>65 years old). It concluded that high omega-3 levels were associated with better white matter grade and a 40% reduction in subclinical infarcts (Sorry for the technical jargon – but both of those are good things in terms of brain function for those of us who are getting a bit older).

The second study (C. M. Milte et al, J of Attention Disorders, 2013, doi: 10.1177/1087054713510562) looked at the effect of omega-3 fatty acids on children (ages 6-13) with ADHD. It concluded that high omega-3 levels were associated with improved spelling and attention and reduced oppositional behavior, hyperactivity, cognitive problems and inattention.

What Is The Common Thread In These Studies?

Why, you might ask, am I comparing a study in the elderly, where the concern is retention of cognitive skills, with a study on ADHD in children?

That’s because there is a very important common thread in those two studies. It wasn’t the amount of omega-3 fatty acids in their diet that counted. It was the levels of omega-3 fatty acids in their blood that made the difference.

The first study included a detailed dietary history to estimate the habitual intake of omega-3 fatty acids in the participants.

  • There was no correlation between estimated dietary intake of omega-3 fatty acids and any measure of brain function in those older adults.
  • However, there was a strong correlation between blood levels of omega-3s and brain health in that population group.

The second study was actually a placebo controlled intervention study in which the children were given 1 gm/day of either omega-3 fatty acids or omega-6 fatty acids.

  • Once again, there was no correlation between dietary intake of omega-3 or omega-6 fatty acids and any outcome related to ADHD.
  • However, there was a strong correlation between blood levels of omega-3 fatty acids or omega-3/omega-6 ratio and improvement in multiple measures of ADHD.

How Could The Effect of Dietary Intake And Blood Levels Of Omega-3s Be So Different?

Fish OilBoth studies were relatively small and suffered from some technical limitations, but the most likely explanations are:

  • Inaccurate recall of the participants as to what they eat on a habitual basis. (study 1)
  • Individual differences in the ability of participants to convert short chain omega-3 fatty acids (found in foods such as canola oil, flaxseed oil and walnuts) to the beneficial long chain fatty acids (found in cold water fish). (study 1)
  • Poor compliance in taking the supplements. (study 2)

Why Are These Studies Important?

The most important insight to come out of both of these studies is that it is essential to actually measure blood levels of omega-3 fatty acids and not just rely on dietary intake or supplementation for a valid clinical trial.

That’s a concern because blood measurements of omega-3 fatty acids are expensive and have not been a part of many of the clinical studies that have been performed to date. Even the largest, best designed clinical study is worthless if the dietary recalls aren’t accurate or people don’t take their capsules.

We need to go back and reevaluate many of the clinical studies that have been published.

We need to ask:

  • Are their conclusions valid?
  • Did some studies fail to show that omega-3s were effective simply because they only measured dietary intake and not how much of the omega-3s actually accumulated in the blood?

The Bottom Line

  • High blood levels of omega-3s in the blood correlated with improved brain health in the elderly and reduced ADHD symptoms in children
  • These studies were small, but they are consistent with a number of other studies that have come to similar conclusions.
  • Blood levels of omega-3s are better predictors than dietary intake for evaluating the health benefits of omega-3 fatty acids.
  • Many previous studies that failed to find an effect of omega-3 fatty acids on brain health, heart health or inflammation did not actually measure blood levels of the omega-3 fatty acids. These studies should be reevaluated.

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