Association between alcohol consumption and risk of stroke among adults: results from a prospective cohort study in Chongqing, China

BACKGROUND: The incidence of stroke in China is increasing, along with a clear trend in the prevalence of risk factors. Alcohol consumption is also a risk factor for stroke. Many cohort studies have explored the relationship between alcohol consumption and stroke risk. However, findings have been inconsistent. METHODS: We used cluster sampling to select 13 districts and counties (at the same level) in Chongqing, China. Then, we used stratified random sampling to distribute the number of people in each district and county. 23,308 adults aged 30–79 were recruited between October 2018 and February 2019. Follow-up was conducted through a monitoring system and questionnaires until September 2022. Information on alcohol consumption and other covariates was collected using a standardized questionnaire. Participants were asked to report their weekly frequency of drinking over the past year and weekly intake of various alcoholic beverages in general. The frequency of drinking was divided into three categories: 1–2 d/week, 3–5 d/week, and 6–7 d/week. The average daily alcohol consumption is calculated based on the amount of alcohol contained in different alcoholic beverages. It is classified as nondrinker (0 g/day), light (0 to 12 g/day), moderate (13 to 36 g/day), and high (> 36 g/day). Cox proportional hazard regression models were used to estimate the association between alcohol consumption and stroke risk. Results are shown as multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs). RESULTS: With an average follow-up of 3.80 years, there were 310 new stroke events. The incidence of total stroke was 368.69 per 100,000 person-years. Overall, after adjusting for covariates, moderate alcohol consumption (average daily alcohol consumption 13–36 g/d) was associated with a lower risk of total stroke (HR: 0.48; 95% CI: 0.25–0.92) compared with nondrinkers. The adjusted HR and 95% CI for total stroke and ischemic stroke for those who drank alcohol 6–7 days per week were 0.60(0.37, 0.96) and 0.53(0.30, 0.94), respectively. The risk of total stroke (HR: 0.39; 95% CI: 0.17–0.89) was reduced in a pattern of drinking 6–7 days per week but with a mean alcohol consumption of less than 36 g/d. There was no significant association between alcohol consumption and hemorrhagic stroke. CONCLUSION: This study suggests moderate alcohol consumption is associated with a lower risk of total stroke. And healthy drinking patterns should be of more significant concern. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-023-16361-9.