Neuroinflammation may contribute to the pathogenesis of Parkinson disease (PD). Use of nonsteroidal anti-inflammatory drugs (NSAID) in general, and possibly ibuprofen in particular, has been shown to be related to lower PD risk in previous epidemiologic studies.

We prospectively examined whether use of ibuprofen or other NSAIDs is associated with lower PD risk among 136,197 participants in the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS) free of PD at baseline (1998 for NHS and 2000 for HPFS). NSAIDs use was assessed via questionnaire. Results were combined in a meta-analysis with those of published prospective investigations.

We identified 291 incident PD cases during 6 years of follow-up. Users of ibuprofen had a significantly lower PD risk than nonusers (relative risk [RR], adjusted for age, smoking, caffeine, and other covariates = 0.62; 95% confidence interval [CI] 0.42–0.93; p = 0.02). There was a dose–response relationship between tablets of ibuprofen taken per week and PD risk (p trend = 0.01). In contrast, PD risk was not significantly related to use of aspirin (RR = 0.99; 95% CI 0.78–1.26), other NSAIDs (RR = 1.26; 95% CI 0.86–1.84), or acetaminophen (RR = 0.86; 95% CI 0.62–1.18). Similar results were obtained in the meta-analyses: the pooled RR was 0.73 (95% CI 0.63–0.85; p < 0.0001) for ibuprofen use, whereas use of other types of analgesics was not associated with lower PD risk.

The association between use of ibuprofen and lower PD risks, not shared by other NSAIDs or acetaminophen, suggests ibuprofen should be further investigated as a potential neuroprotective agent against PD.