Media release

From: Springer Nature

Excess amounts of breakdown products of the essential micronutrient niacin, also known as vitamin B3, may be linked to an increased risk of mortality, heart attacks and stroke, according to a study reported in Nature Medicine this week.

Niacin is used both as a dietary supplement and to fortify flour and cereal. Research has previously shown that niacin can lower levels of low-density lipoprotein cholesterol; however, the vitamin seemingly does not have the expected effects on decreasing cardiovascular disease risk — the so-called ‘niacin paradox.’ This paper provides a potential explanation for this paradox by showing that a breakdown product of niacin may promote inflammation in blood vessels.

In an analysis of plasma samples from 4,325 people in three patient cohorts that include both men and women from the United States and Europe, Stanley Hazen and colleagues found that two breakdown products of niacin — the metabolites N1-methyl-2-pyridone-5-carboxamide (2PY) and N1-methyl-4-pyridone-3- carboxamide (4PY) — are associated with an increased risk of cardiovascular disease. In subsequent human genetic and mouse studies, the authors showed that this increased risk may be mediated by the ability of one of these breakdown products (4PY) to increase the abundance of the pro-inflammatory protein VCAM-1 in the endothelial cells that line blood vessels.

Given these initial findings, Hazen and colleagues note that further work in larger studies is needed to explore the links between niacin and its breakdown products and cardiovascular disease.