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

Should We Use Supplements For Cardiovascular Health?

Posted July 10, 2018 by Dr. Steve Chaney

Are You Just Wasting Your Money On Supplements?

Author: Dr. Stephen Chaney

 

supplements for cardiovascular health wast moneyYou’ve seen the headlines. “Recent Study Finds Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.”  You are being told that supplements are of no benefit to you. They are a waste of money. You should follow a healthy diet instead. Is all of this true?

If I were like most bloggers, I would give you a simple yes or no answer that would be only partially correct. Instead, I am going to put the study behind these headlines into perspective. I am going to give you a deeper understanding of supplementation, so you can make better choices for your health.

 Should we use supplements for cardiovascular health?

In today’s article I will give you a brief overview of the subject. Here are the topics I will cover today:

  • Is this fake news?
  • Did the study ask the right questions?
  • Is this a question of “Garbage In – Garbage Out?
  • Reducing Heart Disease Risk. What you need to know.

All these topics are covered in much more detail (with references) in my book “Slaying The Supplement Myths”, which will be published this fall.

 

How Was This Study Done?

supplements for cardiovascular healthThis study (D.J.A. Jenkins et al, Journal of the American College Of Cardiology, 71: 2540-2584, 2018 ) was a meta-analysis. Simply put, that means the authors combined the results of many previous studies into a single database to increase the statistical power of their conclusions. This study included 127 randomized control trials published between 2012 and December 2017. These were all studies that included supplementation and looked at cardiovascular end points, cancer end points or overall mortality.

Before looking at the results, it is instructive to look at the strengths and weaknesses of the study. Rather than giving you my interpretation, let me summarize what the authors said about strengths and weaknesses of their own study.

The strengths are obvious. Randomized control trials are considered the gold standard of evidence-based medicine, but they have their weaknesses. Here is what the authors said about the limitations of their study:

  • “Randomized control trials are of shorter duration, whereas longer duration studies might be required to fully capture chronic disease risk.”
  • “Dose-response data were not usually available [from the randomized control studies included in their analysis]. However, larger studies would allow the effect of dose to be assessed.”

There are some other limitations of this study, which I will point out below.

Is This Fake News?

supplements for cardiovascular health fake newsWhen I talk about “fake news” I am referring to the headlines, not to the study behind the headlines. The headlines were definitive: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” However, when you read the study the reality is quite different:

  • In contrast to the negative headlines, the study reported:
    • Folic acid supplementation decreased stroke risk by 20% and overall heart disease risk by 17%.
    • B complex supplements containing folic acid, B6, and B12 decreased stroke risk by 10%.
    • That’s a big deal, but somehow the headlines forgot to mention it.
  • The supplements that had no significant effect on heart disease risk (multivitamins, vitamin D, calcium, and vitamin C) were ones that would not be expected to lower heart disease risk. There was little evidence from previous studies of decreased risk. Furthermore, there is no plausible mechanism for supposing they might decrease heart disease risk.
  • The study did not include vitamin E or omega-3 supplements, which are the ones most likely to prove effective in decreasing heart disease risk when the studies are done properly (see below).

Did The Study Ask The Right Question?

Most of the studies included in this meta-analysis were asking whether a supplement decreased heart disease risk or mortality for everyone. Simply put, the studies started with a group of generally healthy Americans and asked whether supplementation had a significant effect on disease risk for everyone in that population.

That is the wrong question. We should not expect supplementation to benefit everyone equally. Instead, we should be asking who is most likely to benefit from supplementation and design our clinical studies to test whether those people benefit from supplementation.

supplements for cardiovascular health diagramI have created the graphic on the right as a guide to help answer the question of “Who is most likely to benefit from supplementation?”. Let me summarize each of the points using folic acid as the example.

 

Poor Diet: It only makes sense that those people who are deficient in folate from foods are the most likely to benefit from folic acid supplementation. Think about it for a minute. Would you really expect people who are already getting plenty of folate from their diet to obtain additional benefits from folic acid supplementation?

The NIH estimates that around 20% of US women of childbearing age are deficient in folic acid. For other segments of our population, dietary folate insufficiency ranges from 5-10%. Yet, most studies of folic acid supplementation lump everyone together – even though 80-95% of the US population is already getting enough folate through foods, food fortification, and supplementation. It is no wonder most studies fail to find a beneficial effect of folic acid supplementation.

The authors of the meta-analysis I discussed above said that the beneficial effects of folic acid they saw might have been influenced by a very large Chinese study, because a much higher percentage of Chinese are deficient in folic acid. They went on to say that the Chinese study needed to be repeated in this country.

In fact, the US study has already been done. A large study called “The Heart Outcomes Prevention Evaluation (HOPE)” study reported that folic acid supplementation did not reduce heart disease risk in the whole population. However, when the study focused on the subgroup of subjects who were folate-deficient at the beginning of the study, folic acid supplementation significantly decreased their risk of heart attack and cardiovascular death.  This would seem to suggest using supplements for cardiovascular health is a good idea.

Increased Need: There are many factors that increase the need for certain nutrients. However, for the sake of simplicity, let’s only focus on medications. Medications that interfere with folic acid metabolism include anticonvulsants, metformin (used to treat diabetes), methotrexate and sulfasalazine (used to treat severe inflammation), birth control pills, and some diuretics. Use of these medications is not a concern when the diet is adequate. However, when you combine medication use with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial.

Genetic Predisposition: The best known genetic defect affecting folic acid metabolism is MTHFR. MTHFR deficiency does not mean you have a specific need for methylfolate. However, it does increase your need for folic acid. Again, this is not a concern when the diet is adequate. However, when you combine MTHFR deficiency with a folate-deficient diet, health risks are increased and supplementation with folic acid is more likely to be beneficial. I cover this topic in great detail in my upcoming book, “Slaying The Supplement Myths”. In the meantime, you might wish to view my video, “The Truth About Methyl Folate.”

Diseases: An underlying disease or predisposition to disease often increases the need for one or more nutrients that help reduce disease risk. The best examples of this are two major studies on the effect of vitamin E on heart disease risk in women. Both studies found no effect of vitamin E on heart disease risk in the whole population. However, one study reported that vitamin E reduced heart disease risk in the subgroup of women who were post-menopausal (when the risk of heart disease skyrockets). The other study found that vitamin E reduced heart attack risk in the subgroup of women who had pre-existing heart disease at the beginning of the study.

Finally, if you look at the diagram closely, you will notice a red circle in the middle. When two or three of these factors overlap, that is the “sweet spot” where supplementation is almost certain to make a difference and it may be a good idea to use supplements for cardiovascular health.

Is This A Question Of “Garbage In, Garbage Out”?

supplements for cardiovascular health garbage in outUnfortunately, most clinical studies focus on the “Does everyone benefit from supplementation question?” rather than the “Who benefits from supplementation?” question.

In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.

Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.

 

Should We Use Supplements For Cardiovascular Health?

 

If you want to know whether supplements decrease heart disease risk for everyone, this meta-analysis is clear. Folic acid may decrease the risk of stroke and heart disease. A B complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but the analysis did not include vitamin E and/or omega-3s.

However, if you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.

I would be remiss, however, if I failed to point out that we know healthy diets can decrease heart disease risk. In the words of the authors: “The recent science-based report of the U.S. Dietary Guidelines Advisory Committee, also concerned with [heart disease] risk reduction, recommended 3 dietary patterns: 1) a healthy American diet low in saturated fat, trans fat, and meat, but high in fruits and vegetables; 2) a Mediterranean diet; and 3) a vegetarian diet. These diets, with their accompanying recommendations, continue the move towards more plant-based diets…” I cover the effect of diet on heart disease risk in detail in my book, “Slaying The Food Myths”.

 

The Bottom Line

 

You have probably seen the recent headlines proclaiming: “Vitamin and Mineral Supplements Don’t Lower Heart Disease Risk.” The study behind the headlines was a meta-analysis of 127 randomized control trials looking at the effect of supplementation on heart disease risk and mortality.

  • The headlines qualify as “fake news” because:
    • The study found that folic acid decreased stroke and heart disease risk, and B vitamins decreased stroke risk. Somehow the headlines forgot to mention that.
    • The study found that multivitamins, vitamin D, calcium, and vitamin C had no effect on heart disease risk. These are nutrients that were unlikely to decrease heart disease risk to begin with.
    • The study did not include vitamin E and omega-3s. These are nutrients that are likely to decrease heart disease risk when the studies are done properly.
  • The authors of the study stated that a major weakness of their study was that that randomized control studies included in their analysis were short term, whereas longer duration studies might be required to fully capture chronic disease risk.
  • The study behind the headlines is of little use for you as an individual because it asked the wrong question.
  • Most clinical studies focus on the “Does everyone benefit from supplementation question?” That is the wrong question. Instead we need more clinical studies focused on the “Who benefits from supplementation?” question. I discuss that question in more detail in the article above.
  • In addition, most clinical studies of supplementation are based on the drug model. They are studying supplementation with a single vitamin or mineral, as if it were a drug. That’s unfortunate, because vitamins and minerals work together synergistically. What we need are more studies of holistic supplementation approaches.
  • Until these two things change, most supplement studies are doomed to failure. They are doomed to give negative results. In addition, meta-analyses based on these faulty supplement studies will fall victim to what computer programmers refer to as “Garbage In, Garbage Out”. If the data going into the analysis is faulty, the data coming out of the study will be equally faulty. It won’t be worth the paper it is written on. If you are looking for personal guidance on supplementation, this study falls into that category.
  • If you want to know whether supplements decrease heart disease risk for everyone, this study is clear. Folic acid may decrease the risk of stroke and heart disease. A B-complex supplement may decrease the risk of stroke. All the other supplements they included in their analysis did not decrease heart disease risk, but they did not include vitamin E and/or omega-3s in their analysis.
  • If you want to know whether supplements decrease heart disease risk for you, this study provides no guidance. It did not ask the right questions.
  • However, we do know that healthy, plant-based diets can decrease heart disease risk. I cover heart healthy diets in detail in my book, “Slaying The Food Myths.”

 

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.

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