Study identifies some supplements beneficial for cardiovascular health

Healthy diets are rich in antioxidants like amino acids, omega-3 fatty acids, and vitamin C, but the beneficial effects of these micronutrients on cardiovascular health have long been controversial. Now, a new meta-analysis published in the Journal of the American College of Cardiology brings some clarity.

The researchers systematically reviewed a total of 884 studies available to date on micronutrients taken as food supplements and analyzed their data. They identified several micronutrients that reduce cardiovascular risk—as well as others that offer no benefit or even have a negative effect. More than 883,000 patients participated in the combined studies.

“For the first time, we have developed a comprehensive, evidence-based, integrative map to characterize and quantify the potential effects of micronutrient supplements on cardiometabolic outcomes,” said Simin Liu, MD, MS, MPH, ScD, Professor of in Epidemiology and Medicine at Brown University. and principal investigator of the study. “Our study highlights the importance of micronutrient diversity and balancing health benefits and risks.”

The results could serve as the basis for future clinical trials to study specific combinations of micronutrients and their impact on cardiovascular healthhe said.

Antioxidant supplementation has long been thought to play a role in heart health. This is because these nutrients work to reduce oxidative stress, a known contributor to many cardiovascular diseases. Heart-healthy diets like the Mediterranean diet and the Dietary Approach to Stop Hypertension (DASH) contain foods that are naturally high in antioxidants. However, results from studies of antioxidant supplements have been inconsistent, one reason why this approach has not yet been widely adopted in preventive cardiology.

“Research on micronutrient supplementation has primarily focused on the health effects of a single or a few vitamins and minerals,” Liu said. “We decided to take a comprehensive and systematic approach to reviewing all publicly available studies reporting on all micronutrients, including phytochemicals and antioxidant supplements, and their effects on cardiovascular risk factors as well as multiple cardiovascular illnesses.”

Researchers reviewed randomized, controlled intervention trials evaluating 27 different types of antioxidant supplements. They found strong evidence that several provided cardiovascular benefits. These included omega-3 fatty acids, which decreased mortality from cardiovascular disease; folic acid, which reduces the risk of stroke; and coenzyme Q10, an antioxidant sometimes marketed as CoQ10, which has reduced all-cause mortality. Omega-6 fatty acids, L-arginine, L-citrulline, vitamin D, magnesium, zinc, alpha-lipoic acid, melatonin, catechin, curcumin, flavanol, genistein and quercetin have also shown evidence of cardiovascular risk reduction.

Not all supplements were beneficial. Vitamin C, vitamin D, vitamin E, and selenium showed no effect on long-term cardiovascular disease outcomes or type 2 diabetes risk, while beta-carotene supplements increased mortality all causes combined.

According to the researchers, the findings underscore the need for more personalized, precision-based dietary interventions that involve specific combinations of beneficial supplements. More studies are needed, including large, high-quality interventional trials to investigate the long-term health effects of certain micronutrients.

“It’s important to identify the optimal mix of micronutrients because not all of them are beneficial and some may even have harmful effects,” Liu said.