Increased Urate Levels May Mean Lower Parkinson's Risk

Scientists at the Harvard School of Public Health (HSPH) have identified a correlation between high levels of urate—a naturally occurring antioxidant found in blood—and a lower risk of Parkinson’s disease, according to a study published online last month in The American Journal of Epidemiology.

Neuron degeneration in Parkinson’s disease is caused in part by oxidative stress, a state of cellular imbalance that can produce molecules damaging to the cellular environment. As a powerful antioxidant, urate could help to correct this, according to the study’s abstract.

“Our results are certainly the strongest out there yet…there is a dramatically strong effect or association that we see,” said lead author Marc G. Weisskopf, an assistant professor of Environmental and Occupational Epidemiology at HSPH.

The results also suggest that elevated urate levels may delay the progression of Parkinson’s disease, according to Weisskopf. Urate also has the potential to become “the first established biomarker of the disease” to gauge Parkinson’s in the way that High-density lipoprotein cholesterol—better known as the “good” cholesterol—is used as a measure of cardiac health, Weisskopf said.

The study followed 18,000 men who provided blood samples between 1993 and 1995 to the Health Professionals Follow-up Study, a 21-year-old all-male study conducted by HSPH. Of this group, 84 individuals were later diagnosed with Parkinson’s disease. Urate levels in these individuals’ blood samples were then monitored and compared with those of control subjects with matching age, race, and time of blood collection.

Previously published papers had pointed to a possible relationship between urate levels and incidence of Parkinson’s disease, but there had not been solid data on it until this paper, Weisskopf said.

While elevated urate levels appear to be beneficial to Parkinson’s patients, Weisskopf said it would be unwise to tell patients to increase their urate levels by diet or supplement, as high levels of urate can lead to gout, increased mortality by up to 20 percent, and negative kidney and cardiovascular symptoms.

“For increasing urate levels across the board, the adverse effects could outweigh the beneficial ones, but if you’re talking about people with slow progression…the beneficial effects may outweigh the adverse effects,” Weisskopf said.

Normally, urate levels are primarily controlled by diet, entering the body via the breakdown of a class of organic compounds known as purines. Alcohol, beans, red meat, and some citrus fruits are some examples of common foods that contain purines, according to Weisskopf.

The study will be published again in the next print edition of The American Journal of Epidemiology, set to be released this month.

—Staff writer Aditi Balakrishna can be reached at balakris@fas.harvard.edu.