In a new, large-scale, prospective study exploring the link between levels of urate in the blood and risk of Parkinson's disease, researchers from the Harvard School of Public Health (HSPH) have found that high levels of urate are strongly associated with a reduced risk of the disease.
The findings were published online on June 20, 2007 in The American Journal of Epidemiology and will appear in an upcoming print issue of the journal.
Urate is a normal component of blood, and although high levels can lead to gout, urate might also have beneficial effects because it is a potent antioxidant. Parkinson's disease is a chronic, progressive nerve disorder associated with destruction of brain cells producing dopamine, a neurotransmitter essential to the normal functioning of the central nervous system.
"This is the strongest evidence to date that urate may protect against Parkinson's disease," said lead author Marc Weisskopf, Assistant Professor of Environmental and Occupational Epidemiology at HSPH.
The researchers used the HSPH-based Health Professionals Follow-up Study, a population of male health professionals established in 1986, as the source for their data. The study cohort included more than 18,000 men without Parkinson's disease who had provided blood samples between 1993 and 1995 and whose subsequent health status was followed.
The researchers found that men in the top quartile of blood urate concentration had 55 percent lower risk of developing Parkinson's disease than men in the bottom quartile. This difference was not explained by differences in age or other risk factors for Parkinson's disease. The results of two previous studies had suggested a possible inverse relation between blood urate and risk of Parkinson's disease, but it is only when the previous data were combined with those of this new study that the evidence became compelling.