Supplement brakes Parkinson's

Coenzyme Q10 may delay brain degeneration.
15 October 2002

HELEN PEARSON

Parkinson's affects around 1 million in the US. © GettyImages

An over-the-counter dietary pill may slow the brain deterioration seen in Parkinson's disease, researchers have announced¹. But patients are being warned not to head for the drugstore just yet.

A dose of the supplement, coenzyme Q10, stalls the onset of some of the movement problems that accompany the disorder, the American Neurological Association meeting will hear today. "It didn't stop progression but it did reduce it," says Clifford Shults of the University of California, San Diego, who led the three-year pilot study.

Existing treatments for the disease relieve the symptoms but do not treat the cause: the breakdown of the nerves in the brain that make the neurotransmitter dopamine. Finding a drug that prevents this decay "is at the centre of everyone's radar screen", says Bill Langston of the Parkinson's Institute in Sunnyvale, California.

The findings of Shults's team are some of the first evidence for such a 'neuro-protective' agent. But experts stress that another large-scale trial will be required before doctors can start recommending daily supplements. "It would be premature to suggest to patients that they should take high levels of Q10," says Shults.

Because the enzyme is already available in drugstores as a dietary supplement, there are concerns that patients might start popping pills prematurely. "An unsuspecting public will be encouraged to buy it without any scientific evidence," warns Parkinson's researcher Warren Olanow of Mount Sinai School of Medicine in New York.

Parkinson's affects roughly a million people in the United States, causing tremors and slowing movement.

Q tip

Some Parkinson's patients have low levels of coenzyme Q10 and scientists hypothesized that this may contribute to nerve degeneration, prompting the trial. The enzyme normally dwells in mitochondria, the power generators of cells. It also acts as an antioxidant, stopping the production of damaging molecules called free radicals.

Shults and his colleagues treated 80 patients in their early 60s who showed initial signs of the disease. The patients received either a daily placebo or 300, 600 or 1,200 milligrams of coenzyme Q10, and were monitored over 16 months or until their symptoms required treatment with conventional dopamine therapy.

The condition of patients taking 1,200 milligrams worsened 40% less over time than that of patients taking the placebo, according to a scale that measures the severity of Parkinson's symptoms. For example, the patients might not need help in dressing themselves, explains Shults. Those taking the lower doses were helped to a lesser extent.

But some experts have voiced concerns over the trial. Looking at symptoms is only an indirect measure of nerve-cell damage, points out Olanow. The enzyme could simply be relieving the symptoms rather than preventing the disease. The trial did not actually delay the time at which patients needed treatment.

The US National Institutes of Health are currently deciding which potential neuro-protective agents to fund in large-scale clinical trials. Other potential treatments include anti-inflammatory drugs. "The field is flush with possible candidates," says Olanow. "The problem is to prove they work."

1. Shults, C. et al. Effects of coenzyme Q10 in early Parkinson disease. Archives of Neurology, 59, 1541 - 1550, (2002). |Article|