Food supplement found to slow Parkinson's disease

A food supplement available in health food shops has become the first compound shown to slow the progression of Parkinson's disease, the chronic neurological disorder that affects 120,000 people in Britain.

American scientists, who published the findings yesterday, described it as a landmark study that could ultimately provide a new way of treating the disease. The results show that the supplement, known as co-enzyme Q10, reduced by 44 per cent the loss of function caused by the disease over 16 months.

None of the current treatments had been shown to delay the advance of the disease, the researchers said. It is caused by the loss of brain cells producing dopamine, resulting in tremor, stiffness and impaired co-ordination. The standard treatment is with levodopa, discovered more than 50 years ago. As with other more modern treatments, though, this only eases the symptoms of the disease. The researchers warned patients not to go out and strip the shelves of health food shops until larger studies had confirmed the findings.

The discovery was presented at the annual meeting of the American Neurological Association in New York and is published in the US journal Archives of Neurology.

Clifford Shults, professor of neurosciences at the University of California, the lead researcher, said: "While it is tremendously encouraging that our results indicate that it is likely that coenzyme Q10 slows the progression of Parkinson's disease, our study did not have sufficient numbers of patients to unequivocally prove that it does."

The preliminary study, known as a phase II trial, was run in 10 centres across the United States and involved 80 patients, all with early-stage Parkinson's. The biggest effect was in improving their ability to feed and dress themselves and perform everyday tasks, with an overall 44 per cent reduced decline in movement and mental function over the 16 months of the study.

Professor Shults said a larger study involving hundreds of patients was necessary to confirm the findings.

Coenzyme Q10 is a naturally occurring substance made in the body that improves the function of mitochondria, the "power houses" that produce energy in the cells. Levels of the coenzyme fall with age and might be linked with some of the diseases of ageing. Deficiency of the coenzyme has also recently been linked with rare mitochondrial diseases in younger people.

The supplement is sold at health food shops and via the internet, but for the quantities used in the study the cost is high. The researchers found only those patients taking the largest dose of 1,200mg a day gained a worthwhile benefit. People taking doses of 300mg and 600mg a day fared only slightly better than those taking a placebo. None of the patients suffered side-effects.

In Britain, the Inhouse Pharmacy, which trades over the internet, sells eight packs of coenzyme 10, each containing 30 tablets of 150mg, for £109.40 – enough for one month's supply for a patient taking 1,200mg a day. The researchers warn that commercial versions of the supplement are not regulated and some may not contain "potentially beneficial amounts".

Robert Meadowcroft, policy director of the Parkinson's Disease Society, described the findings as encouraging. He said: "People with early-stage Parkinson's may think it a good time to take this supplement but do take medical advice first."