Can Coffee Keep Parkinson's Away?

Caffeine helps in mice, says new study

MONDAY, May 14 (HealthScout) -- That morning jolt of java may not be so bad for you after all. At least in mice, caffeine appears to help stop the development of Parkinson's disease, says a new study.

But it's too soon to suggest that an extra latte will stop the disease in people, the researchers say.

"What we showed in this [study] was that caffeine in a mouse model can prevent the loss of dopamine, which is the key chemical signal lost in Parkinson's," says Dr. Michael Schwarzschild, an assistant professor of neurology at Massachusetts General Hospital in Boston.

Parkinson's disease affects 1.5 million Americans, reports the Parkinson's Disease Foundation. Symptoms include loss of movement, tremors, stiffness and poor balance. The cause of the disease is unknown, but people with Parkinson's have much lower levels of the neurotransmitter dopamine. One treatment for Parkinson's is dopamine replacement.

Schwarzschild and colleague Dr. Jiang-Fan Chen studied mice that were given either caffeine in varying doses or a placebo shot before they were injected with a chemically induced form of Parkinson's.

The lowest dose of caffeine was the equivalent of one to two cups of coffee for a human, says Schwarzschild.

The study found that caffeine blocked the brain receptor believed responsible for the dopamine loss. This receptor, known as A2A, has very limited activity, mostly in the small area of the brain that malfunctions in Parkinson's patients.

"The effects were dose-dependent. The more caffeine the [mice] were exposed to, the greater the protective effect, up to the point where there was almost complete protection against the toxic effects," says Schwarzschild.

Results of the study appear in the current issue of the Journal of Neuroscience.

Schwarzschild says the results support those from two large human studies that found the more caffeine consumed, the less likely the development of Parkinson's.

Schwarzschild says scientists have known for some time that blocking the A2A receptor enhances movement in lab mice that have been studied in Parkinson's research.

"Blocking this receptor with a drug holds promise as a symptomatic therapy and has led to clinical trials of such drugs for Parkinson's disease. Our study and others now raise the possibility that such drugs may offer an additional benefit of slowing the course of the disease."

And, Schwarzschild says because A2A acts on such a small area of the brain, treatments to block its activity probably would have few side effects.

The researchers say they don't know what effect caffeine would have had if given to the mice after they'd been given the Parkinson's-like disease.

Dr. Leon Zacharowicz, a neurologist at Nassau University Medical Center in East Meadow, N.Y., says Schwarzschild's study "gives us another piece of the Parkinson's puzzle, and it's nice to know that not everything we do is bad for us."

But he says people shouldn't up their caffeine intake. "The jury is still out, though I would be pleasantly surprised if something as simple as a cup of coffee a day could keep Parkinson's away," he says.

Schwarzschild's plans to compare caffeine intake in human Parkinson's patients to the speed with which the disease progresses.

What To Do

For more information about Parkinson's, go to the Parkinson's Disease Foundation, or to Parkinsons New Zealand.

To learn more about the latest studies on Parkinson's, including others on the relationship between caffeine and the disease, read these HealthScout reports.

SOURCES: Interviews with Michael Schwarzschild, M.D., Ph.D., assistant professor of neurology, Massachusetts General Hospital, Boston, Mass.; Leon Zacharowicz, M.D., M.A., neurologist, Nassau University Medical Center, East Meadow, N.Y.; May 15, 2001, Journal of Neuroscience
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