Some Supplements Found to Benefit Cardiovascular Health, Others May Have Negative Impact

A new study indicates that some micronutrient supplements provide a benefit to cardiovascular health, whereas other supplements are not beneficial at all or can have a negative impact. The study, published in the Journal of the American College of Cardiology, notes that antioxidants such as amino acids, omega-3 fatty acids, and vitamin C are beneficial for overall health, however, the benefit they confer for cardiovascular health is questionable.

The study authors conducted a systematic review on data from 884 randomized, controlled intervention trials on micronutrients taken as dietary supplements in more than 883,000 patients. The investigators found several micronutrients that do not provide a benefit for cardiovascular health and others that actually have a negative impact.

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

Liu added that these findings may help to guide future clinical trials on specific combinations of micronutrients and their impact on cardiovascular health.

Taking antioxidant supplements has traditionally been thought beneficial for heart health because these nutrients help lower oxidative stress, which contributes to multiple cardiovascular diseases. Further, diets found beneficial for cardiovascular health, such as the Mediterranean diet and the Dietary Approach to Stop Hypertension, are heavy on foods naturally rich in antioxidants. However, findings on the benefits of antioxidant supplements for cardiovascular health are inconsistent, which is why they have not been widely adopted in preventative cardiology, according to the authors of the current study.

“Research on micronutrient supplementation has mainly 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 evaluate all the publicly available and accessible studies reporting all micronutrients, including phytochemicals and antioxidant supplements and their effects on cardiovascular risk factors as well as multiple cardiovascular diseases.”

The researchers analyzed intervention trials that evaluated 27 different types of antioxidant supplements, which showed significant evidence of a cardiovascular benefit from some supplements. The micronutrients found to benefit cardiovascular health included omega-3 fatty acids, which lowered mortality from cardiovascular disease; folic acid, which reduced the risk of stroke; and coenzyme Q10—sometimes marketed as CoQ10—which was found to reduce all-cause mortality. Other supplements that showed evidence of benefiting cardiovascular health included omega-6 fatty acid, L-arginine, L-citrulline, vitamin D, magnesium, zinc, alpha-lipoic acid, melatonin, catechin, curcumin, flavanol, genistein, and quercetin.

Conversely, vitamins C, D, and E, and selenium did not have any effect on long-term cardiovascular disease outcomes or the risk of type 2 diabetes, whereas beta carotene supplements were found to increase all-cause mortality, according to the study.

“Supplementation of some but not all micronutrients may benefit cardiometabolic health,” the study authors wrote. “This study highlights the importance of micronutrient diversity and the balance of benefits and risks to promote and maintain cardiovascular health in diverse populations.”

The findings highlight a need for more personalized, precision-based dietary interventions that include specific combinations of beneficial supplements, the study authors noted. They added that large, high-quality interventional trials are needed to evaluate the long-term effects of certain micronutrients on health.

“Identifying the optimal mixture of micronutrients is important, as not all are beneficial, and some may even have harmful effects,” Liu said.

Reference

An P, Peng, et al. Micronutrient supplementation to reduce cardiovascular risk. Journal of the American College of Cardiology. https://www.sciencedirect.com/science/article/abs/pii/S0735109722071066. Published December 5, 2022. Accessed December 6, 2022.