Alcohol Consumption, Types of Alcohol, and Parkinson's Disease

Background: The epidemiologic evidence on alcohol consumption and Parkinson's disease (PD) is equivocal. We prospectively examined total alcohol consumption and consumption of specific types of alcoholic beverage in relation to future risk of PD. Methods: The study comprised 306,895 participants (180,235 male and 126,660 female) ages 50-71 years in 1995-1996 from the NIH-AARP Diet and Health Study. Consumption of alcoholic beverages in the past 12 months was assessed in 1995-1996. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were obtained from logistic regression models. Results: A total of 1,113 PD cases diagnosed between 2000 and 2006 were included in the analysis. Total alcohol consumption was not associated with PD. However, the association differed by types of alcoholic beverages. Compared with non-beer drinkers, the multivariate ORs for beer drinkers were 0.79 (95% CI: 0.68, 0.92) for <1 drink/day, 0.73 (95% CI: 0.50, 1.07) for 1-1.99 drinks/day, and 0.86 (95% CI: 0.60, 1.21) for >= 2 drinks/day. For liquor consumption, a monotonic increase in PD risk was suggested: ORs (95% CI) were 1.06 (0.91, 1.23), 1.22 (0.94, 1.58), and 1.35 (1.02, 1.80) for<1, 1-1.99, and >= 2 drinks/day, respectively (P for trend <0.03). Additional analyses among exclusive drinkers of one specific type of alcoholic beverage supported the robustness of these findings. The results for wine consumption were less clear, although a borderline lower PD risk was observed when comparing wine drinkers of 1-1.99 drinks/day with none drinkers (OR = 0.74, 95% CI: 0.53, 1.02). Conclusions: Our results suggest that beer and liquor consumption may have opposite associations with PD: low to moderate beer consumption with lower PD risk and greater liquor consumption with higher risk. These findings and potential underlying mechanisms warrant further investigations.