October 04, 2017
A 2012 study (2012;79:651-658) published in Neurology by Ronald B Postuma, MD, MSc, and colleagues concluded that 6 weeks of caffeine supplementation seemed to improve objective motor measures in patients with Parkinson disease (PD). Five years later, Dr Postuma and his team conducted another study to investigate longer-term effects of caffeine supplementation. This latest study was unable to find any benefits for patients with PD.
For this latest study, 121 adults with PD (average age 62 years old) were included in a multicenter, parallel-group controlled trial. Half of the study participants were given 200 milligrams of caffeine twice daily (equivalent to about 3 cups of coffee a day), and the other half was given placebo (Neurology. 2017; doi:10.1212/WNL.0000000000004568).
In caffeine-consuming participants, the dosing was gradually increased over the first 9 weeks and only reached 200 milligrams twice daily at week 9, in order to help them adjust to the caffeine.
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According to the authors, no comparable improvement was seen in motor parkinsonism (difference between groups −0.48 [95% confidence interval −3.21 to 2.25]. Similarly, there was no change in motor signs or motor symptoms at any time point, and no difference on quality of life. There was a slight improvement in somnolence over the first 6 months, which attenuated over time. There was a slight increase in dyskinesia with caffeine, and caffeine was associated with worse cognitive testing scores.
Dr. Postuma told Medical News Today (September 28, 2017), “While our previous study showed possible improvement in symptoms, that study was shorter, so it's possible that caffeine may have a short-term benefit that quickly dissipates….Regardless, our core finding is that caffeine cannot be recommended as therapy for movement symptoms of Parkinson’s disease.”—Amanda Del Signore