Popping vitamin and mineral supplements is not an insurance policy against developing heart disease, a new analysis shows.
Only folic acid and vitamin B complex have been shown to have a beneficial effect on cardiovascular outcomes in a meta-analysis of the evidence on vitamin and mineral supplements.
And even the benefits of folic acid supplements may be questionable in countries like Australia that already have food fortification policies.
The analysis of 179 randomised controlled trials found moderate quality evidence that folic acid led to a 20% reduction in stroke, largely driven by the China Stroke Primary Prevention Trial (CSPPT).
Similarly, vitamin B complex reduced the risk of stroke in nine of 12 studies in the meta-analysis. There was no effect from either supplement on all-cause mortality.
The study said the folic acid effect was a ‘substantial new positive finding on supplement use’.
However it cautioned that the effect might be related to the impact of the large CSPPT and the fact there was no folic acid fortification in China.
More commonly used supplements – multivitamins, vitamin D, calcium and vitamin C – failed to show any significant effect on cardiovascular outcomes or all-cause mortality.
However the meta-analysis found niacin and antioxidants were associated with an increased risk of all-cause mortality.
“In the current statin era, the effect of niacin in increasing all-cause mortality by 10% (NNT = 200) in data for 3 RCTs (all of which used extended-release niacin) cautions against long-term use of extended-release (nonflush) niacin as an adjunct to statin therapy,” the study authors said.
It concluded the overall lack of evidence for supplements on CVD outcomes and all-cause mortality was noteworthy.
“In the absence of further studies, the current data on supplement use reinforce advice to focus on healthy dietary patterns, with an increased proportion of plant foods in which many of these required vitamins and minerals can be found.”
Commenting on the findings, Professor Clare Collins, Director of Research in the School of Health Sciences at the University of Newcastle, NSW, said the bottom line was for people to eat more nutrient rich whole foods rather than spend money on supplements.
“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,” she said.
The study was published in the Journal of the American College of Cardiology.