Do Multivitamins Reduce Heart Disease Risk?

Written by Dr. Steve Chaney on . Posted in Healthy Lifestyle, Vitamins and Health, Vitamins and Heart Disease

Will A Multivitamin A Day Keep The Doctor Away?

Author: Dr. Stephen Chaney

 

Junk foods and convenience foods have become the American way. We are perhaps the most overfed and undernourished country on the planet. Even worse, we are exporting our unhealthy lifestyle to the rest of the world.

Because of the foods we eat experts estimate that only somewhere between 3% and 10% of us get the nutrients we need on a daily basis. For the vast majority of Americans who are undernourished, multivitamin use helps us fill the nutritional gaps in our diet.

But could multivitamin use do more than just fill nutritional gaps? Could it also help us protect our health?  Could multivitamins reduce heart disease risk?  Here things get a bit murky. We are confused by conflicting headlines. One day the headlines blare that multivitamins are placebos. They are useless. They are a waste of money. The next day the headlines claim that multivitamins are panaceas that can help protect us from heart disease, cancer, diabetes, and whatever else ails us.

In this week’s Health Tips From the Professor, I will review the latest study claiming that multivitamin use reduces heart disease risk and help you put that study into perspective.

Do Multivitamins Reduce Heart Disease Risk?

 

reduce heart disease riskThe current study (Rautianinen et al, Journal of Nutrition, doi: 10.3945/jn.115.227884, 2016)  was a re-analysis of data collected in the first Physician’s Health Study between 1982 and 1995. That study was originally designed to test the effect of aspirin and/or beta-carotene on heart disease and cancer. It enrolled a total of 22,071 male physicians over the age of 40 and followed them for an average of 12.2 years. The conclusions of the initial study were that aspirin use decreased cardiovascular risk while beta-carotene had little effect on either heart disease or cancer.

However, the study also collected data on a wide range of lifestyle factors (including diet and supplement use) and clinical outcomes, so it has provided a valuable database for many subsequent studies, including this one.

This study analyzed a subset of the population (18,530 male physicians) that did not have any sign of heart disease or cancer at the beginning of the study and looked at the effect of multivitamin usage on several cardiovascular disease outcomes including:

  • Non-fatal heart attacks
  • Non-fatal strokes
  • Death due to cardiovascular disease
  • Total cardiovascular events (the sum total of the previous three events)

Here were the results of the study:

  • When the authors simply asked whether the participants were using multivitamins or not at the beginning of the study, multivitamin use had no effect on any of the cardiovascular disease outcomes listed above. These results are similar to several similar studies.
  • However, when the authors compared those who had been using multivitamins for 20 years or more at the beginning of the study to non-users, long term multivitamin use was associated with a statistically significant 44% decrease in total cardiovascular events.
  • When the authors looked at each of the individual cardiovascular disease outcomes (heart attack, stroke, and death due to cardiovascular disease) there was a similar percentage decrease when comparing 20+ year multivitamin users with non-users, but there were not enough people in each of these individual categories for the differences to be statistically significant.

The authors concluded that their study suggests that “multivitamin use over a long duration may be associated with a lower risk of major cardiovascular events” but that further studies are needed because of the low number of long-term multivitamin users in the study.

Putting This Study Into Perspective

There are several clinical studies looking at the effect of multivitamin use on cardiovascular outcomes that have come up empty handed. However, there are an equal number of clinical studies that have shown a positive effect of multivitamin use on cardiovascular outcomes, at least under certain conditions and with certain population groups. For example:

  • For those physicians who had a prior history of heart disease, multivitamin use was associated with a 44% reduction in the risk of heart attack.  So, in this case multivitamins were shown to reduce heart disease risk.
  • There was a significant effect of age, with physicians who were 70 or older showing a stronger effect of multivitamin use on the reduction of overall cardiovascular disease.
  • This study did not ask how long the participants had been using multivitamins prior to the study so it could not assess the effects of long term multivitamin use.
  • Other studies suggest that long-term multivitamin use could also reduce heart disease risk in women. For example:

In short, the available data suggest that the benefits of multivitamin use are most likely to be apparent with those who are at highest risk of having a heart attack because of age or pre-existing disease as well as those who have been using multivitamins for decades, not just a few years.

Multivitamins And Heart Disease Risk:  Placebo Or Panacea?

placeboIf you just read the headlines you have every right to be confused. Some headlines claim that multivitamins are just placebos. They are a waste of money. Other headlines seem to suggest that multivitamins are panaceas that will prevent everything from heart disease to cancer and diabetes.  As usual, the truth lies somewhere in between.

Let’s start with the obvious. If you are in great health, have a heart healthy diet and lifestyle, and do not have a genetic predisposition to heart disease, your chances of having a heart attack, stroke or other forms cardiovascular disease are very low. A multivitamin might benefit you in other ways, but it is unlikely to significantly reduce your already low risk of heart disease. Many of the subjects in previous studies fall into this category, which is why many of those studies come up empty handed.

The people who are most likely to benefit from multivitamin use are those who have a poor diet, or are at increased risk of heart disease because of genetic predisposition, pre-existing disease or age. None of the studies to date have looked at groups with poor diets or genetic predisposition to see whether multivitamin use did reduce heart disease risk. The one study that did look at groups who were older or had pre-existing disease found a beneficial effect of multivitamin use in those groups.

The recent study, along with several other studies, also suggests that it may require decades of multivitamin use to significantly impact heart disease risk. That makes sense. Heart disease doesn’t just happen overnight. It takes decades to develop, so it is only logical that it might also require many years of multivitamin use to significantly impact heart disease risk.

If so, this highlights a very serious flaw in those studies reporting no effect of multivitamin use on heart disease risk. Most of the negative studies only inquired about multivitamin use at the beginning of the study. They did not ask how long those people had been using multivitamins. If you ignore the long term multivitamin users, you are very likely to get a negative result.

The study featured in this article (Rautianinen et al, Journal of Nutrition, doi: 10.3945/jn.115.227884, 2016)  is a perfect example. The group who had been using multivitamins for 20+ years had a 44% decrease in heart disease risk. However, this group represented only 5% of the multivitamins users. The size of this group was not large enough to influence the overall results. Consequently, when the authors of the study looked at multivitamin users as a whole, there was no significant effect of multivitamin use on heart disease risk.

 

The Bottom Line

The question of whether multivitamin use could reduce heart disease risk has been contentious in recent years, with some studies claiming that multivitamin use has no effect, and other studies suggesting that multivitamin use significantly reduces heart disease risk. A recent study helps provide a better understanding of why previous studies have reported such conflicting results.

  • This study found that when you just asked whether people were using multivitamins or not at the beginning of the study, there was no significant effect of multivitamin use on heart disease risk – in agreement with all of the previous negative studies.  That is because those studies did not take into account the length of multivitamin use.
  • However, when the authors of the study looked at the subgroup who had used multivitamins for 20 years or more, they had a 44% decreased risk of heart disease compared to non-users. It turns out that most of the previous studies reporting a beneficial effect of multivitamin use on heart disease risk also focused on long term multivitamin users.
  • Previous studies have also suggested that multivitamin use may significantly decrease heart disease risk for people at increased risk of heart attack, either due to age or pre-existing heart disease.
  • Taken together these studies suggest that long term multivitamin use may reduce your risk of heart disease. Even short term multivitamin use may be beneficial if you are at increased risk of heart disease.
  • Of course, multivitamin use is just one piece of the heart health puzzle. For the NIH’s recommendation for a heart healthy lifestyle, click a heart healthy lifestyle.

 

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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