Objective:

To examine whether smoking, caffeine intake, and physical activity are associated with the risk of Parkinson’s disease (PD) in Black women.

Background:

Smoking, caffeine intake, and physical activity have consistently been associated with a decreased PD risk in epidemiological studies, but these have predominantly included White individuals. It is unknown whether these findings can be generalized to other populations, such as Black women.

Design/Methods:

We prospectively followed 58,536 participants of the Black Women’s Health Study for the development of PD (1995-2023). Smoking status (current, past, never smoker), caffeine intake (quartiles of mg/day), and physical activity (quartiles of METs/week) were assessed at baseline. We estimated the hazard ratio (HR) of PD and 95% confidence intervals (CI), adjusting for relevant sociodemographic and risk factors. Alternative exposure definitions were considered (pack-years, cups/day, and hours of vigorous activity).

Results:

We identified 95 women with incident PD over a median follow-up of 26 years. The mean age (standard deviation) at baseline was 39 (11) years, and at PD diagnosis was 66 (10) years. Smoking was associated with a lower PD risk (HR and 95% CI for current vs. never smokers= 0.44; 0.20-0.97). A non-statistically significant dose-response relationship was observed between the number of pack-years smoked and the risk of PD (HR and 95% CI per 10 pack-years= 0.88; 0.72-1.08; p-trend 0.21). In contrast, caffeine intake and physical activity were not associated with the risk of PD.

Conclusions:

We provide first-time evidence on how smoking, caffeine intake, and physical activity relate to PD risk in Black women. Our findings on smoking are consistent with those previously reported in the literature. Caffeine intake and physical activity did not appear to impact the risk of PD in this population, which may be related to the younger baseline age compared to previously analyzed cohorts.