Epidemiology studies suggest show a correlation between caffeine intake and reduced risk for Parkinson’s disease. Parkinson’s usually presents with trembling, shaking, and loss of motor coordination. Caffeine is a non-selective adenosine inhibitor. Besides functioning as a signaling molecule and energy carrier in living cells, adenosine is thought to be an inhibitory neurotransmitter, believed to impact sleep and suppress arousal.
A recent study published in Neurology highlights the results of a randomized, controlled clinical study of 61 patients administered caffeine or placebo for 6 weeks. Researchers gauged sleepiness using the Epworth Sleepiness Sleep score and other effects including motor severity, sleep markers, fatigue, and depression.
Findings suggest that caffeine has a minor effect on somnolence (drowsiness).
On the primary intention-to-treat analysis,caffeine resulted in a nonsignificant reduction in Epworth Sleepiness Scale score (-1.71 points; 95% confidence interval [CI] -3.57, 0.13). However, somnolence improved on the Clinical Global Impression of Change (+0.64; 0.16, 1.13, intention-to-treat), with significant reduction in Epworth Sleepiness Scale score on per-protocol analysis (-1.97; -3.87, -0.05).
More impressively, the study suggested that caffeine strongly improves motor function in Parkinson’s patients with few adverse side effects.
Caffeine reduced the total Unified Parkinson’s Disease Rating Scale score (-4.69 points; -7.7, -1.6) and the objective motor component (-3.15 points; -5.50, -0.83). Other than modest improvement in global health measures, there were no changes in quality of life, depression, or sleep quality. Adverse events were comparable in caffeine and placebo groups.
Researchers suggest further study for the potential use of caffeine as a long term treatment for Parkinson’s disease.