A new study suggests having six to nine drinks in one day nearly doubles the risk of heart attack and stroke over the following week.

Just having one drink was found to increase the risk of cardiovascular problems over the next 24 hours, according to Reuters. However, having two to four alcoholic drinks may reduce the risk of heart attack and stroke over the following week, the study found.

“There appears to be a transiently higher risk of heart attack and strokes in the hours after drinking an alcoholic beverage but within a day after drinking, only heavy alcohol intake seems to pose a higher cardiovascular risk,” lead researcher Elizabeth Mostofsky, Sc.D. of the Harvard T.H. Chan School of Public Health said in a news release.

She said the study findings are “consistent with public health recommendations that advise consumption of no more than two drinks per day for men and no more than one drink per day for non-pregnant women.”

Mostofsky and colleagues analyzed data from 23 studies with a total of almost 30,000 participants. They found that when people had about two to four drinks, they had about a 30 percent lower risk of heart attacks and hemorrhagic strokes after 24 hours, compared with their peers who did not drink. They also had a 19 percent lower risk of ischemic strokes within a week than people who did not drink at all.

The study appears in the journal Circulation.

“Just after drinking, blood pressure rises and blood platelets become stickier, increasing the risk of heart attacks and strokes,” Mostofsky said. “However, regularly drinking small amounts of alcohol in the long term appears to both increase levels of HDL cholesterol (high density lipoprotein cholesterol), the so-called good cholesterol, and reduce the tendency to form blood clots.”