Alcohol Does Not Affect Risk of Parkinson's, Study Finds

A study of nearly 140,000 volunteers found that alcohol consumption neither increases nor decreases risk for the disease.

Jacob Gaffney
Posted: July 10, 2003

A team of researchers at the Harvard School of Public Health found that people who drink alcohol may not be at a higher risk of developing Parkinson's disease than nondrinkers, based on data from 136,089 health professionals.

However, said lead author Miguel Hernán, "the study suggests that drinking alcohol does not help reduce the risk of Parkinson's disease" either. Instead, drinking has almost no effect on the risk of developing Parkinson's disease, according to the research, which was published in recent issues of the Annals of Neurology and Pain and Central Nervous System Week.

Earlier work by Hernán found that cigarette smoking and caffeine consumption were associated with lower rates of Parkinson's disease. But researchers are not sure if chemical components, such as nicotine or caffeine, may actually provide some neuroprotective effects. "An alternative explanation is that those who are predisposed to develop PD are also less prone to smoke cigarettes or consume caffeine ..." the authors wrote in their study. "Under this hypothesis, other common habituating behaviors, such as alcohol drinking, could also be inversely related to the risk of PD." Studying alcohol consumption could shed more light on the earlier results.

Parkinson's normally affects both men and women over the age of 60. Its symptoms include an unsteady gait and uncontrollable tremors. In later stages, the condition may also lead to dementia or other degenerative ailments. According to the study, the loss of some specific neurological functions and not others, such as memory, could indicate that certain people may be "predestined" to develop the disease, in that their minds are wired so that they are at higher risk.

According to the study, those who have an aversion to some possible risks, such as smoking, may also wish to "avoid novelty-seeking behaviors," such as drinking a glass of wine in a bar -- and if alcohol consumption had health benefits for Parkinson's disease, those people would not experience them.

To test the possibilities, the researchers looked at two large studies, the Nurses Health Study, of women aged 30 to 55, and the Health Professionals Follow-Up Study, of men aged 40 to 75. Both studies took place over the course of more than a decade.

Every two years, the subjects filled out questionnaires to track, among other things, their alcohol consumption, diet and exercise patterns, as well as the development of chronic illnesses.

Of the participants, 415 developed Parkinson's during the course of the study. The Harvard researchers then compared the sufferers' drinking patterns with those who did not have the illness.

Regardless of how much or how little alcohol was consumed by participants, the researchers found no association between drinking and Parkinson's disease. Breaking down the results according to whether the subjects preferred beer, spirits or wine showed no notable differences in risk.

Few subjects reported drinking more than 30 grams of alcohol per day (the average glass of beer or wine or shot of liquor contains 10 to 15 grams). So the authors admit: "It is still possible that alcohol at higher doses, where consumption is more likely to reflect addictive rather than social behaviors, may be associated with a reduced Parkinson's disease risk."

However, Hernán warns against upping one's daily intake of wine to help prevent contracting the ailment. "Not only there is insufficient evidence that this strategy would work, but also any decision regarding alcohol consumption must take into account the overall effects of alcohol on health," he said.

"Our study is aimed at better understanding the mechanisms that lead to Parkinson's disease," he added, "but it does not necessarily translate into a public health recommendation yet."

For a comprehensive look at the potential health benefits of drinking wine, check out senior editor Per-Henrik Mansson's feature Eat Well, Drink Wisely, Live Longer: The Science Behind a Healthy Life With Wine and The Case for Red Wine

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