(HealthDay News) — In as little as an hour after consuming an alcoholic beverage, cardiovascular risk may go up, according to research published online in Circulation. The findings were also presented at the American Heart Association’s Epidemiology and Prevention/Lifestyle and Cardiometabolic Health 2016 Scientific Sessions, held from March 1 to 4 in Phoenix.

Elizabeth Mostofsky, ScD, instructor at the Harvard School of Public Health and a postdoctoral fellow at Beth Israel Deaconess Medical Center in Boston, and colleagues reviewed 23 previously published studies that compared the risk of heart attack and stroke in the hours and days after drinking alcohol. In all, 29,457 people were included in these studies.

The researchers found that within 1 to 3 hours, a single drink of alcohol increased heart rate and disrupted the heart’s normal rhythm. But at 24 hours, moderate drinking improved blood flow, the functioning of the lining of blood vessels and reduced clotting, the study showed. Moderate drinking — up to 6 drinks a week in the studies — immediately increased the risk for heart attack and stroke, Mostofsky told HealthDay. But within a day, it was protective and tied to a lower risk of heart attack or stroke from bleeding. Within a week, moderate drinking was linked with a lower risk of stroke from clots, she said.

Heavy drinking, however, was associated with higher risk of heart attack and stroke across the board, Mostofsky said. Six to 9 drinks a day increased the risk as much as 2-fold, while 19 to 30 drinks a week increased the risk as much as 6 times. “Heavy drinking increases risk both in the short term and the long term, but drinking smaller amounts has different effects in the subsequent hours than it does in the subsequent days and weeks,” Mostofsky added.


  1. Mostofsky E, Chahal HS, Mukamal KJ, Rimm EB, and Mittleman MA. Alcohol and Immediate Risk of Cardiovascular Events: A Systematic Review and Dose-Response Meta-Analysis. Circulation. doi: 10.1161/CIRCULATIONAHA.115.019743.