• Posted May 31, 2024

Caffeine Affects Dopamine Function in Parkinson's Patients

Caffeine has been associated with a reduced risk of developing Parkinson's disease, but a new study says a coffee jolt might not be good for people already diagnosed with the brain disorder.

Consuming caffeine appears to blunt the brain's ability to use dopamine, the hormone that lies at the heart of Parkinson's symptoms, researchers reported recently in the journal Annals of Neurology.

Patients with high caffeine consumption had an 8% to 15% greater decrease in the ability of dopamine to bind with receptors in the brain, compared to those who took in less caffeine, results show. 

“While caffeine may offer certain benefits in reducing risk of Parkinson's disease, our study suggests that high caffeine intake has no benefit on the dopamine systems in already diagnosed patients,” said principal researcher Valtteri Kaasinen, a professor of neurology with the University of Turku in Finland.

“A high caffeine intake did not result in reduced symptoms of the disease, such as improved motor function,” Kaasinen added in a university news release.

Parkinson's occurs when nerve cells that produce the brain chemical dopamine start to die. 

Reduced levels of dopamine wind up causing the movement problems associated with the disease, including tremors, muscle stiffness and impaired balance and coordination.

For this study, researchers performed brain scans on 163 early-stage Parkinson's patients and 40 healthy people. The scans tracked changes in dopamine patterns within their brains, which were compared to their individual caffeine consumption.

The researchers said the decline in dopamine function isn't likely due to more dopamine neurons dying off due to caffeine intake.

Rather, this reduction in dopamine binding is something that happens when anyone uses caffeine or other stimulants, they added.

More information

The National Institute on Aging has more about Parkinson's disease.

SOURCE: University of Turku, news release, May 28, 2024