According to new research, the risk for stroke appears to double in the hour after having just one drink. The alcoholic drink was defined as wine, beer, or hard liquor. Stroke is the No. 3 killer and a leading cause of long-term disability in the U.S., says the American Heart Association.
However, the researchers also noted that moderate alcohol consumption — less than two drinks per day —appears to be protective over the long term which, may outweigh this temporary rise in immediate risk, according to Science Daily.
“The impact of alcohol on your risk of ischemic stroke appears to depend on how much and how often you drink,” said Dr. Murray Mittleman, senior author of the Stroke Onset Study (SOS) and an epidemiologist at the Harvard T.H. Chan School of Public Health.
An ischemic stroke is caused by a blood clot in a blood vessel leading to the brain. Before the SOS study, researchers were not clear about the link between alcohol and strokes. There have been some studies that found that consuming less than two drinks daily may potentially lower the risk in the long term, according to the Express.
Mittleman and his colleagues interviewed 390 ischemic stroke patients (209 men and 181 women) about three days after their stroke, asking them questions about their lifestyles. They excluded patients who were unable to communicate clearly after being impaired by their stroke. Fourteen patients had consumed alcohol within one hour of stroke onset. When compared to the times when alcohol wasn’t consumed, the relative risk of stroke was 2.3 times higher in the first hour.
The study, published in Stroke: Journal of the American Heart Association, found that the risk rose 1.6 times higher in the second hour, and then fell 30% lower after 24 hours.
The pattern was the same whether the study subjects consumed wine, beer, or distilled spirits, says Express, even when the researchers eliminated patients who had been exposed to other potential triggers, such as exercise or drinking a caffeinated beverage.
“The evidence on heavy drinking is consistent. Both in the long and short term it raises stroke risk,” said Mittleman. “But we’re finding it’s more complicated with light to moderate drinking. It is possible that the transiently increased stroke risk from moderate alcohol consumption may be outweighed by the longer-term health benefits.”
One possible reason for the study results is that blood pressure rises, and blood platelets become stickier after consuming alcohol, which could lead to an increased risk of forming a blood clot. However, consistent use of small amount of alcohol is linked to positive changes in blood lipid levels and more flexible blood vessels, which could reduce overall risk of a stroke.
“At this point we don’t have enough evidence to say that people who don’t drink should start, or that people who drink small amounts ─ on the order of one drink a day ─ should stop,” said Mittleman.