Most supplements ‘ineffective’ in reducing cardiovascular disease: Study

While vitamin and supplement use have become the norm for many when it comes to managing an array of health conditions, experts have warned that there’s inadequate data about the effectiveness of these interventions when it comes to staving off heart disease or helping people live longer.

Despite a number of items on the market promising to reduce the risk of cardiovascular events, new research published in the Annals of Internal Medicine Journal claims few nutritional supplements or dietary interventions offer any protection against cardiovascular disease or death. What’s worse is some may even cause harm.

Cardiovascular disease is a collective term for diseases of the blood vessels and heart and includes a range of conditions such as coronary heart disease, high blood pressure, stroke, heart failure and arrhythmia.

While current US dietary guidelines do recommend healthy eating patterns, routine supplement use isn’t recommended to cut the risk of cardiovascular disease and other chronic issues. Still, one in two Americans use some form of supplement to improve their overall health, while 70 per cent of over-60s used at least one supplement and 29 per cent use at least four.

Researchers from West Virginia University analysed 277 randomised controlled trials of close to one million people to determine the effects of 16 nutritional supplements and eight dietary interventions when it came to reducing the risk of cardiovascular disease in adults. It followed previous research which found some stroke benefits when folate supplementation was taken, but no cardiovascular benefits from multivitamins, vitamin C, vitamin D or calcium supplementations.

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It was found that a low-salt diet may reduce the risk of death in people without high blood pressure. Omega-3, long-chain fatty acids were protective when it came to heart attack and coronary heart disease, while folic acid showed some protective benefit when it came to stroke.

“Reduced salt intake was associated with improving overall survival and cardiovascular mortality. This is something that can be backed up with logic because there is a sufficient amount of data, in various studies, that shows low salt intake basically improves hypertension, which directly influences cardiovascular outcome,” lead author Safi Khan said in a statement.

Still, researchers found calcium combined with vitamin D intake actually increased the risk of stroke. Other popular supplements including multivitamins, selenium, fish oil, vitamin A, vitamin B6, vitamin C, vitamin E, vitamin D alone, calcium alone, folic acid and iron didn’t have a significant effect on mortality or cardiovascular outcomes.

And, while many people use dietary interventions such as the Mediterranean diet (typically high in fruits, vegetables, legumes, fish and cereals, but low in dairy, meat, sugar and saturated fat)
to improve their heart health, researchers found this diet also did little to reduce cardiovascular disease.

“The reason we conducted this study was that millions of people in the United States and across the world consume supplements or follow certain dietary patterns, but there was no good-quality evidence to suggest that these interventions have any effect on cardiovascular protection,” Khan said.

The research is already causing debate in the medical profession, with authors of an accompanying editorial from the Scripps Research Translational Institute claiming the findings of the latest research are limited by the quality of the evidence. They explained that geographic considerations among the studies needed to be considered.

For example, they found that the reported benefit of folate seems to be largely driven by the inclusion of one study from China, where a folate-rich diet is not routine.

Other studies relied on food diaries which were based on a person’s memory of what they consumed. The authors argued that this is not “wholly reliable”.

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It’s always important to talk to a GP or health professional before taking any supplements to ensure they’re effective in managing individual health circumstances. Supplements may interact with other medication or may not be effective for certain conditions.

Do you take supplements to manage any health conditions? How effective do you think they are?