Differences in Parkinson's Disease Risk with Caffeine Intake and Postmenopausal Hormone Use

Area of Science:

• Neuroscience
• Epidemiology
• Nutritional Science

Background:

• Caffeine intake is associated with a lower risk of Parkinson's disease (PD).
• This association is well-established in men but shows inconsistencies in women, potentially due to interactions with post-menopausal hormone (PMH) use.

Purpose of the Study:

• To evaluate the association between caffeine consumption and the risk of developing Parkinson's disease.
• To assess whether post-menopausal hormone (PMH) use modifies the relationship between caffeine intake and PD risk in women.

Main Methods:

• The study analyzed data from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS).
• Dietary caffeine intake was assessed using validated food frequency questionnaires every four years.
• Incident Parkinson's disease diagnoses were confirmed via medical record review, and Cox proportional hazards models were used to estimate hazard ratios (HR).

Main Results:

• A total of 1,219 Parkinson's disease cases were documented.
• The highest quintile of caffeine intake was associated with a 50% lower risk of PD in men (HR: 0.50, 95% CI: 0.37-0.68).
• A potential interaction between coffee intake and PMH use was observed in women (P=0.08), with lower PD risk associated with increased coffee intake in pooled analyses of men and women not using PMH.

Conclusions:

• Increased caffeine intake is associated with a reduced risk of Parkinson's disease.
• This protective association appears consistent in men and in women who have never used post-menopausal hormones.