Is caffeine consumption associated with risk for Parkinson disease? Is there a short-term benefit to caffeine that is sustainable over the long term? These questions and more in this quiz.
Is caffeine consumption associated with significantly decreased risk for Parkinson disease? Is there a short-term benefit to caffeine that is sustainable over the long term? Find out in this quiz.
Several epidemiological studies have suggested that caffeine consumption may be associated with significantly decreased risk for Parkinson disease (PD). A meta-analysis of 173 studies about early nonmotor symptoms of PD found that the risk of PD was 33% lower among coffee drinkers (OR 0.67).1 While the mechanism remains unclear, some scientists have proposed that a neuroprotective effect may be involved. However, research cannot rule out reverse causality (for example, prodromal PD symptoms may decrease the use of caffeine), symptomatic benefit (for example, the possibility that caffeine may improve motor symptoms and delay PD diagnosis), or other factors that may be involved.
In a recent randomized controlled trial of patients with stable PD, 60 were randomized to 200 mg caffeine (about the amount in two cups of coffee) twice daily and 61 to placebo for six months. Results showed that motor symptoms did not improve with caffeine compared to placebo (difference in mean MDS-UPDRS-III score: -0.48 points, 95% CI -3.21, 2.25).2 Results from an earlier, six-week study by the same group showed that caffeine may improve motor symptoms of PD.3 Together, the results suggest a short-term benefit for caffeine that may not be sustained over longer term followup. The results also suggest that epidemiological links between caffeine consumption and decreased risk of PD may not be explained by a beneficial impact of caffeine on motor symptoms of PD.
Results from a randomized controlled trial found that cognitive scores and dyskinesia were worse while daytime sleepiness was improved in patients with PD randomized to six months of 200 mg caffeine twice daily, compared to placebo.2 When the trial was extended to 18 months, combined results for all time points continued to suggest worsening of cognition (difference in MoCA score: 0.66, 95% CI 0.01, 1.32), and worsening of dyskinesia (difference in MDS-UPDRS part IV, 0.25, 95% CI 0.05, 0.45). Improvement in daytime sleepiness was equivocal (difference in SCOPA scores: -0.42, 95% CI -1.09, 0.25).
1. Noyce AJ, Bestwick JP, Silveira-Moriyama L, et al. Meta-analysis of early nonmotor features and risk factors for Parkinson disease. Ann Neurol. 2012;72:893-901.
2. Postuma RB, Anang J, Pelletier A, et al. Caffeine as symptomatic treatment for Parkinson disease (CafÃ©-PD): A randomized trial. Neurology. 2017;89:1795-1803.
3. Postuma RB, Anang AE, Munhoz RP, et al. Caffeine for treatment of Parkinson disease: a randomized controlled trial. Neurology. 2012;79:651-658.