Light to moderate alcohol drinkers may have a lower risk of cancer and cardiovascular disease (CVD) compared to heavy drinkers and those who abstain entirely, according to a study.
The Chinese study stratified 83,732 adults who did not have cancer or CVD at baseline into six groups based on self-reported weekly alcohol consumption (in grams): 0, 1 to 25, 26 to 150, 151 to 350, 351 to 750, and >750. Medical records were used to determine incident cases of cancers, CVD, and mortality.
Median follow-up was 10 years, during which time incident cases of cancers (n=2,947), CVD (n=6,411), and deaths (n=6,646) were recorded. There was J-shaped correlation between alcohol consumption and all three outcomes. The lowest risk was observed among those who consumed 25 g alcohol/week—roughly two servings per week. When adjusting for age, sex, lifestyle, socioeconomic status, and medication use, the hazard ratios for the outcomes, compared to drinking 1 to 25 g alcohol/week, were: for 0, 1.38 (95% confidence interval [CI], 1.29-1.49); for 26 g to 150 g/week, 1.15 (95% CI, 1.04-1.27); for 151 g to 350 g/week, 1.22 (95%CI, 1.10-1.34); for 351 g to 750 g/week, 1.33 (95% CI, 1.21-1.46); and for >750 g/week, 1.57 (95% CI, 1.30-1.90).
Analyses were also performed based on smoking status, which appeared to affect outcomes: alcohol and smoking had a significant interaction (P for interaction <0.001) in terms of the three outcomes, but this interaction was not seen between alcohol and age, sex, and occupation. For these analyses, the >750 g/week patients were combined with the 351 g to 750 g/week group because the former group was too small. In never smokers and past smokers, the correlation between alcohol intake and cancer, CVD, and death was stronger compared to in current smokers.
“Because alcohol consumption and smoking are common addictive behaviors and co-vary, smoking could mask the effect of alcohol alone on health status,” the researchers remarked. “As expected, although the protective association of light-to-moderate alcohol to CVD, cancer, and mortality was significant in both smokers and non-smokers, it was stronger in non-smokers. However, even for lung cancer, light alcohol consumption still showed lowest risk, compared to non-drinkers and heavy drinkers.”
The study was published in the Nutrition Journal.