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EXPERT REACTION: Popping vitamin pills won't help your heart, in fact it may be killing you

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In a review of 179 different studies, Canadian and French scientists say there's no evidence that popping vitamin or mineral pills protects against or helps to treat heart disease, and some supplements - vitamin B3 (niacin) and antioxidants - may actually increase the risk of death. The one exception is folic acid supplements, which may reduce the risk of stroke. The best way to look after your heart is by getting your vitamins and minerals naturally from a healthy diet which includes lots of fruit and veg, they say.

Journal/conference: Journal of The American College Of Cardiology

Organisation/s: University of Toronto, Canada

Media Release

From: The American College of Cardiology

Most Vitamin, Mineral Supplements Not Shown to Lower Heart Disease Risk
Naturally derived nutrients from plant-based foods recommended to cut heart disease risk

Current research does not show enough evidence that vitamin or mineral supplements are beneficial for preventing or treating heart disease, with the exception of folic acid for reducing stroke risk, according to a review article published in the Journal of the American College of Cardiology. Current recommendations to adopt healthy diets that are heavy in plant-based foods from which these vitamins are derived naturally should be reinforced.

Vitamins and minerals have long been used to treat nutrient deficiencies; however, in recent years supplements have been promoted as a means for overall health and longevity. According to the National Health and Nutrition Examination Survey, in 2012, it was estimated that 52 percent of the population were taking supplements.

Despite high use, there is no agreement on whether individual vitamins or minerals or combination supplements should be taken to prevent or treat heart disease. The U.S. Dietary Guidelines Advisory Committee recommend three diets to reduce heart disease risk: a healthy American diet low in saturated fat, trans fat and red meat, but high in fruit and vegetables; a Mediterranean diet; and a vegetarian diet.

In this review, researchers looked at 179 randomized controlled trials on vitamin and mineral supplement use published from January 2012 to October 2017 to determine if a benefit existed. This time frame includes papers published before and after the U.S. Preventive Services Task Force issued guidelines on the use of vitamins, minerals and multivitamins for primary prevention of cardiovascular disease and cancer in 2013.

Researchers found that data on the four most commonly used supplements—multivitamins, vitamin D, calcium and vitamin C—showed no consistent benefit for the prevention of cardiovascular disease, myocardial infarction or stroke, nor was there a benefit for all-cause mortality. Folic acid alone and B-complex vitamins in which folic acid was a component did show a reduction in stroke; however, niacin (vitamin B3) and antioxidants were associated with an increased risk of all-cause mortality. 

These findings confirm the latest U.S. Preventive Services Task Force recommendation in 2014 that stated, “current evidence is insufficient to assess the balance of benefits and harms of single or paired nutrient supplements for the prevention of cardiovascular disease and cancer.”

The one exception seems to be the benefit of folic acid for stroke prevention. A 2015 publication from the China Stroke Primary Prevention Trial (CSPPT) study showed that folic acid supplements may reduce cardiovascular disease and stroke risk. The current JACC review also showed a 20 percent reduction in stroke with folic acid alone.

A May 7 JACC study from the CSPPT also showed hypertensive adults with low platelet count who took a daily pill of both enalapril and folic acid daily saw a 73 percent risk reduction in first stroke when compared to enalapril alone.

“Folic acid administration and the reduction of cardiovascular disease through stroke seen in the Chinese CSPPT trial provides the only example of cardiovascular disease risk reduction by supplement use in the period following the Preventive Services Task Recommendation,” said David J.A. Jenkins, MD, PhD, DSc, lead author of the review and professor and Canada research chair in nutrition and metabolism, Department of Nutritional Sciences, University of Toronto. “Whether these data are sufficient to change clinical practice in areas of the world where folic acid food fortification is already in place is still a matter for discussion.”

Limitations of the review include: the researchers did not consider data from cohort studies, which are longer and more representative of the general population than randomized clinical trials. Also, grouping many types of antioxidants may have been suboptimal since their mechanisms of action may also be very different.

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Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives and reflect independent opinion on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Professor Clare Collins is a NHMRC Senior Research Fellow, Director of Research in the School of Health Sciences, and Acting Director of Priority Research Centre in Physical Activity & Nutrition at The University of Newcastle

 The research study in the Journal of the American College of Cardiology  reviewed 179 randomised controlled trials (RCT) intervention studies that tested the impact of taking a range of vitamin and mineral supplements on developing and treating heart disease and on all-cause mortality.

They evaluated the impact of four common types of nutrient supplement (multivitamins, vitamin D, calcium and vitamin C) on cardiovascular disease (CVD) risk and mortality. This identified that there were no significant effects for CVD events OR for all-cause mortality for these four common vitamins. This means there was no benefit, or harm from taking them.

They also evaluated the impact of less common ones that they had identified as having significant results for  important clinical outcomes for all-cause mortality, CVD mortality and total CVD risk ( including  myocardial infarction or stroke). This identified that there were significant reductions in total CVD events for taking folic acid (the numbers needed to treat (NNT) = 111) and in incidence of stroke for folic acid (NNT = 167) and for B-complex ( where folic acid was a component of the supplement) for stroke (NNT= 250).

Before you rush to start taking folic acid, it is worth noting  that folic acid reduced stroke in just 2 of 7 RCTs (RR = 0.80, p = 0.003) with the effects largely driven by the large China Stroke Primary prevention trial ( n= 20,000 and 5 years).  In China that is no folic acid fortification program in China (like there is in Australia and the USA) and that there was no reduction in all-cause mortality for taking either folic acid or  B-complex vitamins.

Also men at risk of prostate cancer need to be aware that there may be an increased risk of prostate cancer in those taking high dose folic acid.

In terms of other potential harms, they found evidence  that there were marginally significant increase in all-cause mortality for taking ‘antioxidant' supplements (NNH = 250) and among those taking statin medication to lower blood cholesterol and who were also taking slow or extended release niacin (vitamin B3) supplements. This 10% increased risk of all-cause mortality was identified across the 3 RCTs, with the numbers need to harm (NNH) = 200.

What this review shows is that the eating habits of people in Westerns countries is not optimal. It also highlights that taking supplements as an 'insurance policy' does not work. If it did there should have been a reduction in all-cause mortality. That there is an increase in mortality for some supplement categories should be a 'wake up' call that stronger regulations are needed related to supplement use and more support is needed to help people eat better. 

The bottom line is to eat more nutrient rich whole foods.

Foods high in folate include green leafy vegetables, legumes, seeds, poultry, eggs, cereals and citrus fruits. Many bread and breakfast cereals in Australia are fortified with folate. 

Niacin is found in lean meats, milk, eggs, wholegrain breads and cereals, nuts, leafy green vegetables and protein-containing foods.

Last updated: 28 May 2018 3:49pm
Declared conflicts of interest:
None declared.
Dr Carly Moores is an Associate Lecturer and Research Associate in the College of Nursing & Health Sciences at Flinders University

In Australia, supplement use is also very common with almost 30% of Australians reporting consuming supplements in our latest Australian Health Survey (2011-12, Australian Bureau of Statistics). Supplements are widely available but their use should be informed and monitored by a qualified health care professional such as your GP. They are most effective when they address an existing deficiency or when the required intake of some nutrients is difficult to meet from the diet alone, e.g. in women planning pregnancy or currently pregnant. 

However in most cases, the best way to consume the vitamins and minerals you need for optimal health – including to minimise your risk of chronic disease and cardiovascular disease – is to consume a diet rich in foods from the five food groups, and in particular the vegetables, legumes and beans group. We know that less than 4% of Australian children and adults regularly consume the recommended serves of vegetables and legumes/beans as per the Australian Dietary Guidelines (Australian Health Survey 2011-12, Australian Bureau of Statistics). To increase your vegetable intake, include vegetables in each of your daily meals and incorporate them as snacks during the day.

Last updated: 28 May 2018 1:35pm
Declared conflicts of interest:
None declared.
Dr Yutang Wang is a Senior Lecturer in the School of Applied and Biomedical Sciences, Faculty of Science and Technology, Federation University Australia

The 2011–2012 National Nutrition and Physical Activity Survey showed that supplement use was high among Australian adults, with 47% of women and 34% of men taking supplements.

Does this practice matter? This latest review suggests maybe not.

This paper showed that none of the supplements enhance longevity. Most of the vitamin or mineral supplement showed no benefit against heart disease, and some supplements (vitamin B3 and antioxidants) even increased the risk of death.

The one exception is folic acid. A clinical trial in China has recently shown that folic acid supplements may reduce the risk of stroke. Whether this is true for Australians is unknown because folic acid food fortification is already in place in Australia, which is not the case in China. 

Vitamins and minerals are essential nutrients to maintain our health. Most of us can get enough of them from a healthy diet which includes lots of fruits and vegetables. However, for those who cannot, taking supplements should be beneficial. This should be done with a doctor’s advice. Taking too much of these supplements can do us harm.

For example, research has shown that increased folate and vitamin B12 in the blood are associated with increased risk of prostate cancer, the most commonly diagnosed cancer in Australian men.

Last updated: 28 May 2018 1:27pm
Declared conflicts of interest:
None declared.
Professor John Funder AC is a Distinguished Scientist at the Hudson Institute of Medical Research, is from the Department of Medicine, Monash University, and a Professorial Associate in the Centre for Neuroscience, The University of Melbourne

The manuscript by Jenkins et al Supplemental Vitamins and Minerals for CVD Prevention and Treatment published in the Journal of the American College of Cardiology identified previous randomized controlled trials and then estimated cardiovascular disease outcome and all cause mortality by meta-analysis. It has 39 authors, largely from diverse institutions in Ontario, plus input from Boston and Paris.

A key word is 'Supplemental', depending on whether the context is bringing low levels up into the normal range, or whether it means just additional potential therapeutic utility in the context of normal levels. A salient example of this dichotomy is the finding that Vitamin B3 (also known as niacin or nicotinic acid), 'taken at pharmacological doses (1- 3 g/day) in three RCTs'  plus a slow release statin showed a 10% increase in all cause mortality versus statin alone (p=0.05). Fine - but this can and probably will be read to damn the use of B3 in many vitamin complexes offered to pregnant women, which are many orders of magnitude lower than the blockbuster doses used in the trials cited.

This would be a great pity, given the recent discovery of mutations in the enzymes required for the synthesis of NAD (nicotinamide adenine dinucleotide) in children with major developmental abnormalities, and the ability of giving equivalently genetically compromised pregnant mice vitamin B3 to normalise outcomes for their offspring.

There is one other unusual feature of this paper. Details of the support received by various sources among the authors carefully runs to exactly 100 lines of tiny type. Some support is from Foundations, academic and (probably) pro bono, which again is fine. What is striking is that the the parenthesis (investigator-initiated, unrestricted grant) occurs only once in the list of over 90 sources of support enjoyed by the lead author. One would be reluctant to conclude that all the rest were commissioned research, with all its pitfalls - but as presented, you cannot but wonder.

Last updated: 28 May 2018 1:27pm
Declared conflicts of interest:
None declared.
Dr Ian Musgrave is a Senior Lecturer in the Faculty of Medicine, School of Medicine Sciences, within the Discipline of Pharmacology at the University of Adelaide.

The latest research of vitamins and heart disease risk is neither unexpected nor surprising.

While vitamins are essential for our health and diseases like scurvy almost banished from developed countries, people have assumed that if a bit of vitamin is good for you a lot is much better. The latter sentiment has turned out not to be true.

There was some basis to the idea that taking more than the recommended daily intake of vitamins, the level that will prevent vitamin deficiency, might be beneficial. In aging, cancer and heart disease damaging by-products of respiration, reactive oxygen species, are elevated. Researchers thought that anti-oxidant vitamins could prevent some of the damage in these conditions.

Unfortunately, although reactive oxygen species are damaging in the wrong place the body uses them for cell communication and killing bacteria. Treatment with high dose antioxidant vitamins had no beneficial effect on aging or cancer. Indeed, some fat-soluble antioxidant vitamins increased the risk of cancer, especially beta-carotene and lung cancer in smokers. The effect was small but clear. Several studies suggested that vitamin supplementation had no or slightly harmful effects in heart disease too.

This latest paper is a meta-analysis that pulls together high quality studies on vitamins and heart disease. Consuming most vitamin and mineral supplements above the recommended daily intake in general had no effect on either preventing nor treating heart disease.

Consistent with findings in cancer, supplementation with antioxidant vitamins were associated with a small but statistically significant increase in all-cause mortality as was niacin.

One piece of good news is that folate supplementation, which is beneficial in reducing neural tube defects, significantly reduced stroke and total cardiovascular disease. Research has consistently shown that eating a varied diet rich in fresh fruit and vegetables is protective against both cancer and heart disease.

This latest research emphasises that this effect is not due to the vitamins alone, and that good eating habits cannot be replaced by supplements.

Last updated: 28 May 2018 1:25pm
Declared conflicts of interest:
None declared.
Dr Alan Barclay is an accredited practicing dietitian and nutritionist, author and academic and a Research Associate at the University of Sydney.

This systematic review and meta-analysis of 179 randomised controlled trials in humans investigated the effect of vitamin and mineral supplements on the risk of heart disease and stroke. The researchers found that for the four most commonly used supplements—multivitamins, vitamin D, calcium and vitamin C—there was no consistent benefit for the prevention of heart disease or stroke, nor was there a benefit for all-causes of death. Folic acid alone and B-complex vitamins in which folic acid was a component did show a reduction in stroke; however, niacin (vitamin B3) and antioxidants (e.g. vitamins A, C and E) were associated with an increased risk of all-causes of death. 
 
This new research supports the fact that the best way to obtain life’s essential nutrients is by consuming the best quality foods and drinks that you can afford, in amounts proportional to your optimal body weight. Dietary supplements rarely provide vitamins and minerals in optimal amounts, and the form provided is not always the same as what is found in foods and drinks. Our nutrient requirements are best described by a U-shaped curve – too little is not good for health, but then too much can be detrimental also.
 
Based on current scientific evidence, the best way to reduce the risk of heart disease and stroke is to follow a healthy Australian diet proportionally low in saturated fat (no more than 1/3rd of total fat), trans fat and processed red meats, but high in fruit, vegetables and wholegrains; a Mediterranean-style diet; or a vegetarian diet.
 
Regular physical activity (at least 30 minutes a day, 5 times per week), and not smoking are of course other important factors that reduce the risk of heart attacks and stroke.

Last updated: 28 May 2018 1:24pm
Declared conflicts of interest:
None declared.
Dr Rosemary Stanton OAM, Nutritionist, Visiting Fellow, School of Medical Sciences, University of New South Wales

More than half of Australians have swallowed the line that it’s good to take supplements. But it's not a good idea - according to a thorough review of randomised controlled trials that looked at the effects of vitamin and antioxidant supplements. This review concluded that money spent on vitamin and antioxidant supplements is not only wasted, but could occasionally be harmful.
 
That finding doesn’t go down to well with those selling supplements. There may be lots of money to be made selling supplements to gullible people, but these products cannot match the literally thousands of important components available in healthy foods such as fruit, vegetables, wholegrains, fish, nuts and seeds.
 
The real problems with the Australian diet are that people ignore healthy products and choose too many junk food and drinks. These foods not only contribute 35% of adults’ and 40% of children’s kilojoules but they’re high in added sugars, salt and unhealthy kinds of fat. Taking a supplement can’t undo the adverse effects of these problem ingredients.
 
Rather than spending money on supplements, it makes much more sense to enjoy healthy (and delicious) foods. It’s not difficult to choose healthy foods in Australia. Guidelines are available at eatforhealth.gov.au.

Last updated: 25 May 2018 3:20pm
Declared conflicts of interest:
Rosemary has not declared any conflicts of interest.

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