The naturally occurring compound coenzyme Q10 is the first treatment to actually slow down Parkinson's disease, rather than just treating its symptoms. The current treatments for Parkinson's disease can help alleviate the movement disorders that accompany the condition, but they do not actually stop the underlying brain damage. In Parkinson's, cells in the substantia nigra, at the base of the brain, are slowly destroyed, leading to a number of motor and emotional symptoms.

In a preliminary study, the popular food supplement coenzyme Q10 actually seems to slow down the progress of the disease, as opposed to treating the symptoms. Researchers at the University of California gave a group of 80 people with Parkinson's either a varying dose of coenzyme Q10 (300, 600 or 1200 milligrams a day) or placebo for 16 months, assessing various aspects of their illness every four months.

Those on the highest dose of coenzyme Q10 had far better ratings than those on placebo - being 44 per cent better at the end of the study. The researchers believe that the compound actually slows down the condition, but want to carry out brain imaging studies to confirm this.