Alcohol consumption can elevate a person’s risk of ische­mic stroke by 2.3 times in the first hour after ingestion compared with risk during alcohol-free periods, regardless of the type of liquor consumed.

Interviews with 209 men and 181 women (average age: 68 years) conducted a median of three days post-stroke revealed that 248 of the patients consumed wine, beer, and/or liquor in the prior year, 104 within 24 hours of stroke onset, and 14 within one hour of stroke onset. The investigators calculated the relative risk of stroke in the hour after drinking to be 2.3, which was similar for different types of alcoholic beverages and when the sample was restricted to persons who were not exposed to other potential stroke triggers at the time, such as exercising vigorously or drinking a caffeinated beverage. The relative risk fell to 1.6 times higher in the second hour after drinking, returned to baseline within the next three hours, and was 30% lower than baseline after 24 hours.

The average frequency of alcohol consumption in the year prior to stroke was 4.42 times per week. Patients reported that they usually drank small amounts each time, and only 13 said they typically drank more than two servings. Although regular heavy drinking has been noted to raise the risk for ischemic stroke, in this population “such heavy consumption was rare and unlikely to explain our findings,” pointed out senior author Murray A. Mittleman, MD, DrPH, in a report published in the journal Stroke online ahead of print on July 15. The authors further noted that the evidence regarding light to moderate alcohol consumption on ischemic stroke risk is mixed.