Caffeine reported to benefit patients with Parkinson's disease

Robin Wulffson MD's picture
Parkinson's disease, coffee, tea, caffeine, motor function
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A new study has reported that caffeine may benefit patients with Parkinson’s disease. Canadian and Brazilian researchers published their findings online on August 1 in the journal Neurology.

The researchers note that epidemiologic studies have consistently associated caffeine with a lower risk of Parkinson’s disease; however, the symptomatic effects of caffeine in Parkinson’s disease have not been adequately evaluated. Therefore, they conducted a six-week randomized controlled trial of caffeine in patients with Parkinson’s disease.

The study group was comprised of 61 patients; 31 were randomized to receive a placebo and 30 received a caffeine tablet. Participants who consumed an average of one cup of coffee a day were chosen for the study. The patients assigned to the caffeine arm of the study were for the study were given caffeine 100 mg twice daily for three weeks, then 200 mg twice daily for three weeks. The higher dose was the equivalent of between two and four cups of coffee per day. The others were given a matching placebo.

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The patients had a condition known as daytime somnolence, which is a state of near-sleep or a strong desire for sleep. The primary outcome measure of the study was to measure the effect of caffeine on daytime somnolence. Daytime somnolence was measured by the Epworth Sleepiness Scale score. All participants had an Epworth score greater than 10. A number in the 0–9 range is considered to be normal while a number in the 10–24 is abnormal. Secondary outcomes included motor severity, sleep markers, fatigue, depression, and quality of life.

The researchers found that caffeine resulted in a non-significant reduction in Epworth Sleepiness Scale score (−1.71 points). However, after six weeks, those receiving caffeine supplements averaged a five-point improvement in Parkinson's severity ratings compared to those getting the placebo. A major problem with Parkinson’s disease is the slowing of movements. Movements are smaller and slower and accompanied by stiffness and rigidity. For example, Parkinson’s disease sufferers move with a slow, shuffling gait. This was the area that significant improvement occurred in the caffeine arm of the study. Those receiving caffeine averaged a three-point improvement in the speed of movement and amount of stiffness compared to the placebo group; however, there were no changes in reported quality of life, depression, or sleep quality.

The researchers concluded that caffeine provided only minimal improvement in daytime somnolence in patients with Parkinson’s disease; however, it significantly improved objective motor measures. They noted that the potential motor benefits suggest that a larger long-term trial of caffeine is indicated.

Lead author Ronald B. Postuma, MD, MScDr, a neurologist at McGill University Health Centre’s research institute, noted that the motor-related benefits from caffeine are comparable to those seen with medications used to treat Parkinson’s disease that stimulate dopamine production. It is known that individuals suffering from Parkinson’s disease have a loss of dopamine-producing cells in the brain. Caffeine is a natural product contained in coffee, tea, and cola beverages, which has no major adverse effects. In contrast, pharmaceuticals do have adverse effects and are associated with significant cost. Natural products containing caffeine are inexpensive; furthermore, caffeine tablets are even less expensive—about 10 cents a tablet.

Reference: Neurology

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