Alcohol intake and Parkinson's disease risk in the million women study

BACKGROUND: Alcohol intake may be associated with a lower risk of Parkinson's disease (PD), but findings from previous studies have been inconclusive. OBJECTIVE: To determine the association between alcohol intake and PD risk in the Million Women Study, a large, prospective study of women in the UK. METHODS: Between 1996 and 2001, approximately 1.3 million women in the UK, mean age 56 (standard deviation, 5) years, were recruited into the Million Women Study. Information on alcohol intake, lifestyle factors, and medical history was collected at recruitment by questionnaire. Information on incident cases of PD was ascertained by record linkage to national hospital admission records and death registrations. We estimated multivariable-adjusted relative risks and corresponding 95% confidence intervals using Cox proportional hazards models according to categories of alcohol intake. RESULTS: During an average of 17.9 years of follow-up, 11,009 women had a new record of PD among 1,309,267 women. In drinkers, the multivariable-adjusted relative risk comparing women who drank more than 14 drinks of alcohol per week with women who drank 1 to 2 drinks of alcohol per week was 0.99 (95% confidence interval: 0.90, 1.10). Results did not materially change after excluding the first 10 years of follow-up (relative riskadjusted = 1.01; 95% confidence interval: 0.90, 1.13). There were no significant trends in alcohol-related PD risk among never smokers. Additionally, examining this association by type of alcohol intake also yielded null findings. CONCLUSION: These results do not support an association between alcohol intake and PD risk in women. © 2019 International Parkinson and Movement Disorder Society.