Parkinson’s disease is the second most common neurodegenerative disease. It is characterized by the death of dopamine-generating cells in the brain.
In a major review study, people who drank 3 cups of coffee per day had a 29% lower risk of Parkinson’s disease. Going up to 5 cups per day had very little additional benefit (17).
There are many other studies showing that coffee (and tea) drinkers have a reduced risk of Parkinson’s (18, 19).
It’s important to note that in the case of Parkinson’s, the caffeine itself appears to be responsible. Decaffeinated coffee doesn’t have any protective effect (20).
Numerous studies show that people who drink caffeinated coffee (but not decaf) have a lower risk of Parkinson’s disease.