Moderate alcohol intake reduces risk of ischemic stroke in Korea

Objective: We undertook a population-based, case-control study to examine a dose-response relationship between alcohol intake and risk of ischemic stroke in Koreans who had different alcoholic beverage type preferences than Western populations and to examine the effect modifications by sex and ischemic stroke subtypes. Methods: Cases (n 1,848) were recruited from patients aged 20 years or older with first-ever ischemic stroke. Stroke-free controls (n 3,589) were from the fourth and fifth Korean National Health and Nutrition Examination Survey and were matched to the cases by age (±3 years), sex, and education level. All participants completed an interview using a structured questionnaire about alcohol intake. Results: Light to moderate alcohol intake, 3 or 4 drinks (1 drink 10 g ethanol) per day, was significantly associated with a lower odds of ischemic stroke after adjusting for potential confounders (no drinks: reference; <1 drink: odds ratio 0.38, 95% confidence interval 0.32-0.45; 1-2 drinks: 0.45, 0.36-0.57; and 3-4 drinks: 0.54, 0.39-0.74). The threshold of alcohol effect in women was slightly lower than that in men (up to 1-2 drinks in women vs up to 3-4 drinks in men), but this difference was not statistically significant. There was no statistical interaction between alcohol intake and the subtypes of ischemic stroke (p 0.50). The most frequently used alcoholic beverage was one native to Korea, soju (78% of the cases), a distilled beverage with 20% ethanol by volume. Conclusions: Our findings suggest that light to moderate distilled alcohol consumption may reduce the risk of ischemic stroke in Koreans.