Do B Vitamins Reduce Heart Disease Risk?

Written by Dr. Steve Chaney on . Posted in current health articles, Drugs and Health, Health Current Events, Healthy Lifestyle, Supplements and Health, Vitamins and Health

What Role Do B Vitamins Play in a Heart Healthy Lifestyle?

Author: Dr. Stephen Chaney

b vitamins reduce heart attack riskTwo weeks ago I shared some studies that challenge the claim that vitamin E doesn’t reduce heart attack risk. To close out “Heart Health” month, I want to share some information that may change how you think about B vitamins and heart disease risk. Once again, you’ve seen the headlines: “B Vitamins Do Not Reduce the Risk of Heart Disease”. In fact, these headlines have been repeated so many times that virtually every expert thinks that it has to be true. Once again, I’m going to share some information with you that I learned from a seminar by Dr. Jeffrey Blumberg who disagrees with this commonly held belief.

Dr. Blumberg is a Professor in the Friedman School ofNutrition Science and Policy at Tufts. Dr. Blumberg has over 200 publications in peer-reviewed scientific journals. He is considered one of the world’s top experts on supplementation, and his specialty is conducting and analyzing clinical studies. He believes that the media has seriously misinterpreted the studies on B vitamins and heart disease risk. You might call this “The Rest of the Story” because you (and your doctor) definitely did not hear this part of the story in the news.

Do B Vitamins Reduce Heart Disease Risk?

heart disease in menThe study in question is called the “Heart Outcomes Prevention Evaluation-2“. In that study a group of middle aged men and women received 2.5 mg of folate, 50 mg of vitamin B6 and 1 mg of vitamin B12 versus a placebo and were followed for an average of 5 years.

The headlines that you may have seen said “B vitamins do not reduce the risk of major cardiovascular events in patients with vascular disease”. But, the headlines did not tell the whole story.

In the first place, that was only true for heart attacks and cardiovascular death. Strokes were reduced by 25%. I don’t know about you, but I consider strokes to be fairly major.

However, even when we focus on heart attacks and cardiovascular deaths the headlines didn’t tell the whole story. You see, even the best intentioned studies sometimes contain fatal flaws that aren’t obvious until after the study has been completed.

The Flaws In The Study

flawsThere were two major flaws in this study.

Flaw #1 was that 70% of the study subjects were eating foods fortified with folate and had adequate levels of that nutrient in their bloodstream before the study started.

For those people who were already getting enough folate in their diet, B vitamin supplementation didn’t make much of a difference. However, for those people not getting adequate levels of folate in their diet, B vitamin supplementation decreased their risk of heart disease by ~15%.

Flaw #2 was that ~90% of the people in the study had a history of coronary artery disease and most of them were already on cholesterol lowering medications.

To understand why this is a problem you have to understand both the proposed mechanism by which B vitamin supplementation has been proposed to lower the risk of heart disease AND how the cholesterol lowering drugs work.

Deficiencies of folate, B6 and B12 are thought to increase the risk of heart disease because the B vitamin deficiency causes an increase in homocysteinelevels in the blood, and high homocysteine levels are thought to increase inflammation – which is a risk factor for heart disease.  So supplementation with folate, B6 and B12 has been proposed to decrease heart disease risk by decreasing inflammation.

The problem is that the most commonly used cholesterol lowering medications also decrease inflammation.So you might not be surprised to learn that those people who had a history of coronary artery disease(and were taking cholesterol lowering medication that reduces inflammation) did not receive much additional benefit from B vitamin supplementation.

For those people in the study who were not taking cholesterol lowering medication, B vitamin supplementation also reduced their risk of heart attacks by ~15% – but there were too few people in that group for the results to be statistically significant.

So the headlines from this study really should have said “B vitamins do not reduce the risk of heart attacks or cardiovascular deaths in people who are already getting adequate folate from their diet or in people who are taking drugs that reduce the bad effects of B vitamin deficiency”. But that kind of headline just wouldn’t sell any newspapers.

What Does This Study Mean For You?

There are two very important take-home lessons from this study.

Lesson #1:  Once again this study makes the point that supplementation makes the biggest difference when people have an increased need. The studies discussed in Vitamin E and Heart Disease  two weeks ago illustrated increased need because of age, pre-existing disease, and genetic predisposition. This study illustrated increased need because of inadequate diet.

Lesson #2:  This study also illustrates a problem that is becoming increasingly common in studies of supplementation. It is considered unethical to not provide participants in both groups with what is considered the standard of care for medical practice. In today’s world the standard of care includes multiple drugs with multiple side effects, and some of those drugs may have the same mechanism of action as the supplement.

I have discussed this problem in the context of omega-3 fatty acids and heart disease in a previous “Health Tips From the Professor,”  Is Fish Oil Really Snake Oil?   In many cases it is no longer possible to ask whether supplement X reduces the risk of a particular disease. It is now only possible to ask whether supplement X provides any additional benefit for patients who are taking multiple drugs, with multiple side effects. That’s not the question that many of my readers are interested in.

 

The Bottom Line

  • Headlines have proclaimed for years the “B Vitamins Do Not Reduce Heart Disease Risk”. Dr. Jeffrey Bloomberg of Tufts University has reviewed one of the major studies behind this claim and found the headlines to be misleading.
  • For example, the study showed that B vitamin supplementation reduced strokes by 25%, which is a pretty significant finding in itself.
  • When he analyzed the portion of the study looking at heart attacks, he found two major flaws:

#1:  70% of the people in the study were already getting adequate amounts of B vitamins from their diet and would not be expected to benefit from supplementation. For the 30% who weren’t getting adequate amounts of B vitamins from their diet, supplementation reduced their risk of heart attack by 15%.

#2:  90% of the people in the study were taking a drug that masks the beneficial effects of B vitamin supplementation. For the 10% who weren’t taking the drug, supplementation with B vitamins also reduced their risk of heart attack by 15%, but there were too few people in that group for the results to be statistically significant.

Obviously, there were only a handful of people in the study who weren’t getting enough B vitamins from their diet AND weren’t on medication, so we have no idea what the effect of B vitamin supplementation was in that group.

  • Once again this study makes the point that supplementation makes the biggest difference when people have an increased need. The studies discussed in “Health Tips From the Professor” two weeks ago illustrated increased need because of age, pre-existing disease, and genetic predisposition. This study illustrated increased need because of inadequate diet.
  • This study also illustrates a problem that is becoming increasingly common in studies of supplementation. It is considered unethical to not provide participants in both groups with what is considered the standard of care for medical practice. In today’s world the standard of care includes multiple drugs, some of which may have the same mechanism of action as the supplement.

In many cases it is no longer possible to ask whether supplement X reduces the risk of a particular disease. It is now only possible to ask whether supplement X provides any additional benefit for patients who are taking multiple drugs, with multiple side effects. That’s not the question that many of my readers are interested in.

 

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.

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Latest Article

Can Plant-based Diets Be Unhealthy?

Posted September 10, 2019 by Dr. Steve Chaney

Do Plant-Based Diets Reduce Heart Disease Deaths?

Author: Dr. Stephen Chaney

 

plant-based diets vegetablesPlant-based diets have become the “Golden Boys” of the diet world. They are the diets most often recommended by knowledgeable health and nutrition professionals. I’m not talking about all the “Dr. Strangeloves” who pitch weird diets in books and the internet. I am talking legitimate experts who have spent their life studying the impact of nutrition on our health.

Certainly, there is an overwhelming body of evidence supporting the claim that plant-based diets are healthy. Going on a plant-based diet can help you lower blood pressure, inflammation, cholesterol and triglycerides. People who consume a plant-based diet for a lifetime weigh less and have decreased risk of heart disease, diabetes, and cancer.

But, can a plant-based diet be unhealthy? Some people consider a plant-based diet to simply be the absence of meat and other animal foods. Is just replacing animal foods with plant-based foods enough to make a diet healthy?

Maybe not. After all, sugar and white flour are plant-based food ingredients. Fake meats of all kinds abound in our grocery stores. Some are very wholesome, but others are little more than vegetarian junk food. If you replace animal foods with plant-based sweets, desserts, and junk food, is your diet really healthier?

While the answer to that question seems obvious, very few studies have asked that question. Most studies on the benefits of plant-based diets have compared population groups that eat a strictly plant-based diet (Seventh-Day Adventists, vegans, or vegetarians) with the general public. They have not looked at variations in plant food consumption within the general public. Nor have they compared people who consume healthy and unhealthy plant foods.

This study (H Kim et al, Journal of the American Heart Association, 8:e012865, 2019) was designed to fill that void.

 

How Was The Study Done?

plant-based diets studyThis study used data collected from 12,168 middle aged adults in the ARIC (Atherosclerosis Risk in Communities) study between 1987 and 2016.

The participant’s usual intake of foods and beverages was assessed by trained interviewers using a food frequency questionnaire at the time of entry into the study and again 6 years later.

Participants were asked to indicate the frequency with which they consumed 66 foods and beverages of a defined serving size in the previous year. Visual guides were provided to help participants estimate portion sizes.

The participant’s adherence to a plant-based diet was assessed using four different well-established plant-based diet scores. For the sake of simplicity, I will include 3 of them in this review.

  • The PDI (Plant-Based Diet Index) categorizes foods as either plant foods or animal foods. A high PDI score means that the participant’s diet contains more plant foods than animal foods. A low PDI score means the participant’s diet contains more animal foods than plant foods.
  • The hPDI (healthy plant-based diet index) is based on the PDI but emphasizes “healthy” plant foods. A high hPDI score means that the participant’s diet is high in healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) and low in animal foods.
  • The uPDI (unhealthy plant-based diet index) is based on the PDI but emphasizes “unhealthy” plant foods. A high uPDI score means that the participant’s diet is high in unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) and low in animal foods.

For statistical analysis the scores from the various plant-based diet indices were divided into 5 equal groups. In each case, the group with the highest score consumed the most plant foods and least animal foods. The group with the lowest score consumed the least plant foods and the most animal foods.

The health outcomes measured in this study were heart disease events, heart disease deaths, and all-cause deaths. Again, for the sake of simplicity, I will only include 2 of these outcomes (heart disease deaths and all-cause deaths) in this review. The data on deaths were obtained from state death records and the National Death Index. (Yes, your personal information is available on the web even after you die.)

 

Do Plant-Based Diets Reduce Heart Disease Deaths?

plant-based diets reduce heart deathsThe participants in this study were followed for an average of 25 years.

The investigators looked at heart disease deaths over the 25 years and compared people with the highest intake of plant foods to people with the highest intake of red meat and other animal foods. The results were:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, coffee and tea) had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods (refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts) had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

What Else Did The Study Show?

The investigators made a couple of other interesting observations:

  • The association of the overall diet with heart disease and all-cause deaths was stronger than the association of individual food components. This underscores the importance of looking at the effect of the whole diet on health outcomes rather than the “magic” foods you hear about on Dr. Strangelove’s Health Blog.
  • Diets with the highest amount of healthy plant foods were associated with higher intake of carbohydrates, plant protein, fiber, and micronutrients, including potassium, magnesium, iron, vitamin A, vitamin C, folate, and lower intake of saturated fat and cholesterol.
  • Diets with the highest amount of unhealthy plant foods were associated with higher intake of calories and carbohydrates and lower intake of fiber and micronutrients.

The last two observations may help explain some of the health benefits of plant-based diets.

 

Can Plant-Based Diets Be Unhealthy?

plant-based diets unhealthy cookiesNow, let’s return to the question I asked at the beginning of this article: “Can plant-based diets be unhealthy?” Although some previous studies have suggested that unhealthy plant-based diets might increase the risk of heart disease, this study did not show that.

What this study did show was that an unhealthy plant-based diet was no better for you than a diet containing lots of red meat and other animal foods.

If this were the only conclusion from this study, it might be considered a neutral result. However, this result clearly contrasts with the data from this study and many others showing that both plant-based diets in general and healthy plant-based diets reduce the risk of heart disease deaths and all-cause deaths compared to animal-based diets.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

There is one other subtle message from this study. This study did not compare vegans with the general public. Everyone in the study was the general public. Nobody in the study was consuming a 100% plant-based diet.

For example:

  • The group with the highest intake of plant foods consumed 9 servings per day of plant foods and 3.6 servings per day of animal foods.
  • The group with the lowest intake of plant foods consumed 5.4 servings per day of plant foods and 5.6 servings per day of animal foods.

In other words, you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet.

 

The Bottom Line

A recent study analyzed the effect of consuming plant foods on heart disease deaths and all-cause deaths over a 25-year period.

When the investigators looked at heart disease deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had a 19-32% lower risk of dying from heart disease than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

When the investigators looked at all-cause deaths over the 25 years:

  • People with the highest intake of plant foods and the highest intake of healthy plant foods had an 11-25% lower risk of dying from any cause than people with the highest intake of red meat and other animal foods.
  • People with the highest intake of unhealthy plant foods had the same risk of dying from heart disease as people with the highest intake of red meat and other animal foods.

The main message from this study is clear.

  • Replacing red meat and other animal foods with plant foods can be a healthier choice, but only if they are whole, minimally processed plant foods like whole grains, fruits, vegetables, nuts, legumes, coffee and tea.
  • If the plant foods are refined grains, fruit juices, French fries and chips, sugar sweetened and artificially sweetened beverages, sweets and desserts, all bets are off. You may be just as unhealthy as if you kept eating a diet high in red meat and other animal foods.

A more subtle message from the study is that you don’t need to be a vegan purist to experience health benefits from adding more whole, minimally processed plant foods to your diet. The people in this study were not following some special diet. The only difference was that some of the people in this study ate more plant foods and others more animal foods.

For more details on the study, read the article above.

 

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

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