People who moderately consume beer may reduce their risk of developing Parkinson’s disease by 27%, compared with nondrinkers.
SAN DIEGO—Moderate consumption of beer is associated with a lower risk for Parkinson’s disease, while greater consumption of liquor is linked with a higher risk, according to a study presented at the 136th Annual Meeting of the American Neurological Association. Total alcohol consumption, however, was not associated with a risk for Parkinson’s disease, researchers reported.
“Unlike studies regarding Parkinson’s disease risk and smoking or coffee-drinking, previous studies on alcohol consumption and the risk for Parkinson’s disease generated inconsistent results, and few studies examined relationships for individual types of alcohol drinks,” study investigator Honglei Chen, MD, PhD, from the Aging & Neuroepidemiology Group of the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, told Neurology Reviews.
“Our study supports the very preliminary evidence that beer consumption is related to a lower Parkinson’s disease risk,” Dr. Chen continued. “On the other hand, high liquor consumption is related to a higher Parkinson’s disease risk.”
Measuring Alcohol Consumption’s Impact on Parkinson’s Disease Risk
Led by Rui Liu, PhD, also from the Aging & Neuroepidemiology Group of the National Institute of Environmental Health Sciences, the team of investigators examined the association between alcohol consumption and risk of Parkinson’s disease in more than 300,000 participants from the NIH-AARP Diet and Health Study. The researchers assessed participants’ alcohol consumption in 1995 to 1996 and the occurrence of Parkinson’s disease from 2000 to 2006.
In total, 1,113 cases of Parkinson’s disease were identified, while 305,785 persons remained disease-free. “Total alcohol consumption was not associated with Parkinson’s disease,” Dr. Liu and her colleagues stated; however, analysis for specific types of alcohol consumed yielded differential results. After adjusting for potential confounders and other types of alcohol consumption, the researchers determined that the odds ratio for beer drinkers was 0.79 for less than one drink per day, 0.73 for one to 1.99 drinks per day, and 0.86 for two or more drinks per day.
For liquor consumption, the odds ratios increased to 1.06 for less than one drink per day, 1.22 for one to 1.99 drinks per day, and 1.35 for two or more drinks per day. “Results for wine consumption were less clear,” the researchers wrote, “although a lower Parkinson’s disease risk was also observed when comparing drinkers of one to 1.99 drinks per day with nondrinkers.”
The Role of Alcohol Consumption in Parkinson’s Disease Etiology
The mechanisms for the observed relationships between alcohol consumption and disease risk are unclear, the researchers noted, but the differential associations with individual types of alcohol may suggest mechanisms other than, or in addition to, ethanol.
“One possible explanation may relate to plasma urate,” Dr. Chen explained. “For example, unlike wine or liquor, beer contains a large amount of purine, which may work synergically with ethanol to augment urate. Uric acid is a potent free-radical scavenger, and accumulating epidemiologic evidence has linked higher plasma urate with a reduced risk of Parkinson’s disease and slower clinical progression among Parkinson’s disease patients.”
Although Dr. Chen noted that the results of the current study are “too preliminary to make any suggestions” to the general public, he concluded, “[Our] findings highlight the importance of evaluating individual types of alcohol to better understand the role of alcohol drinking in Parkinson’s disease etiology.