Postuma would like to conduct larger trials on caffeine to see if the effects of the stimulant wear off over time.
The good news, he said, is that caffeine is "incredibly safe and well-tolerated."
So, "if you've been avoiding caffeine because you think it's bad, you can stop. If you're sleepy during the day, you can try it," Postuma said. People with heart rhythm problems, uncontrolled high blood pressure or active ulcers should talk with their doctors about whether they should have caffeine in their diet, however.
Home-brewed coffee tends to have less caffeine than what you get at a coffee shop, Postuma noted. Most people shouldn't go over 400 mg to 500 mg a day (about four to five cups), he advised. And, if you don't want caffeine to interrupt your sleep, try to have your last cup of coffee with lunch.
Learn more about Parkinson's disease from the U.S. National Institute of Neurological Disorders and Stroke.
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