Background: The association between Parkinson's disease (PD) risk and alcohol intake is a controversial topic.Objectives: To systematically assess the association between PD risk and alcohol intake.Methods: PubMed and Embase databases were searched for eligible studies with prospective design on PD risk and alcohol intake. A meta-analysis with a random-effects model and dose-response analysis was performed. Relative risk ratios (RRs) with 95% CIs were calculated.Results: Eleven prospective studies were included. Overall, a higher intake of alcohol was inversely associated with PD risk (RR: 0.81, 95% CI: 0.70–0.95, I² = 73.7%). Significant differences existed between the specific types of alcoholic beverages and geographic area. Specifically, a significant association existed for beer (RR: 0.78, 95% CI: 0.65–0.94, I² = 0.0%) and studies conducted in Asia (RR: 0.66, 95% CI: 0.55–0.80, I² = 37.3%). Dose-response analysis indicated a nonlinear relationship between PD risk and alcohol exposure. No evidence for publication bias was detected.Conclusions: In summary, our meta-analysis suggests that alcohol consumption was associated with a decreased risk of PD, with a nearly U-shaped association. Future studies are warranted to clarify the question of a specific type of alcoholic beverage-dependent association, geographic area effect, and possible threshold effects regarding both the adverse and beneficial effects of alcohol.

Objective: Gliomas are the most common primary brain tumors in adults, and the role of hormone therapy (HT) in their development remains controversial. This study with a cohort design aimed to investigate the association between HT use and glioma risk using the data from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Methods: We analyzed data from 75,335 women, aged 50-78, who were enrolled between 1993 and 2001. The median follow-up period was 11.82 years. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between HT use and glioma risk, adjusting for various potential confounders. Results: Over the follow-up period, 101 participants were diagnosed with glioma. After adjusting for relevant variables, there was no significant association between HT use and glioma risk (HR, 1.16; 95% CI, 0.75-1.81). Similarly, no significant associations were found when considering HT status or duration of use. However, in subgroup analysis by education, marital status, body mass index, oral contraceptive, hysterectomy, ovariectomy, ever been pregnant, age at menarche, and age at menopause, we found that a significant positive association was only observed in the group with at least college graduate (HR, 3.00; 95% CI, 1.02-8.84). The interaction effect for education was not significant ( P = 0.056) Conclusions: Our findings suggest no overall link between HT use and glioma risk. Further research is needed to confirm these results.