In July 2019 researchers from the USA published their review of the medical scientific literature to assess the effects of nutritional supplements and dietary interventions on cardiovascular outcomes in adults. A total of 277 studies and 24 interventions, involving 992,129 individuals were included in the review. Results showed that there was moderate-certainty evidence that reduced salt intake decreased the risk of dying prematurely from any cause in individuals with normal blood pressure and from cardiovascular disease in individuals with high blood pressure. In addition, there was low-certainty evidence that omega-3 long-chain polyunsaturated fatty acid was associated with a reduced risk for heart attacks and coronary heart disease whilst folic acid was associated with a reduced risk of stroke. However, there was moderate certainty evidence that combined calcium and vitamin D increased the risk for stroke. In addition, there was very low- to moderate-certainty evidence that other nutritional supplements, such as vitamin B6, vitamin A, multivitamins, antioxidants, and iron and dietary interventions, such as reduced fat intake, had any significant effect on cardiovascular disease outcomes.
Khan SU etg al. Effects of Nutritional Supplements and Dietary Interventions on Cardiovascular Outcomes: An Umbrella Review and Evidence Map. Ann Intern Med. 2019 Jul 9. [Epub ahead of print]