Parkinson’s disease is a chronic and progressive movement disorder. This means that the symptoms continue to worsen with time. The cause is not known, and as there is currently no cure, treatment focuses on managing the symptoms. Parkinson’s involves the malfunction and death of neurons in the brain, primarily in the substantia nigra. Some of these dying neurons produce dopamine, which controls movement and coordination. As more neurons malfunction and die, the dopamine produced in the brain decreases, leaving the person unable to effectively control movement. The primary motor signs of Parkinson’s include; tremors of the hands, arms, legs, jaw, and face; bradykinesia, or slowness of movement; rigidity, or stiffness of the limbs and trunk; and postural instability, or impaired balance and coordination.1
Impact of coffee on Parkinson’s disease
Over the years, many studies have been done to see the relationship between Parkinson’s disease and coffee. These studies show a dose-responsive relationship between coffee consumption and a reduced risk of developing Parkinson’s. Two meta-analyses of 20 and 26 studies respectively reported the global risk of developing Parkinson’s disease decreased by 31% and 25% in coffee drinkers compared to non-coffee drinkers. Some of the individual studies showed huge risk reductions; one study found an 80% reduction of risk of developing Parkinson’s when more than 4 cups of coffee were consumed per day.
The link between coffee and risk reduction of Parkinson’s is harder to see in women; the interaction between caffeine and hormonal therapy still needs further studies into it. One study found a U shaped relation between coffee and Parkinson’s risk reduction, suggesting that, for women, a moderate intake of coffee had the most protective effect. A further study, performed on 77,713 women found that in those not taking post-menopausal hormones, coffee had the same impact on reducing Parkinson’s risk as it did in men. For women taking estrogens, the risk for Parkinson’s was similar to men consuming a low amount of coffee daily, but the reduction of risk for Parkinson’s increased four-fold in women who were drinking 6 or more cups of coffee per day, compared to those not drinking any.2
Sources
1 Parkinson's Disease Foundation (PDF) - What is Parkinson's Disease?
2 Coffee & Health - Coffee and Parkinson's disease