The Journal: Journal of Neurology, Neurosurgery and Psychiatry

The Study: People who take risks with their health appear to be less likely to develop Parkinson’s disease. A team of researchers from England, Australia and the Netherlands looked at a group of 212 individuals—half of whom had Parkinson’s disease—and found that the Parkinson's patients were less likely ever to have smoked. They also drank less alcohol and caffeine than their unaffected counterparts.

How could these habits protect against a degenerative brain disorder that affects movement? One possibility, which earlier studies have suggested, is  that nicotine, alcohol and caffeine somehow protect some parts of the brain, either directly or indirectly.

But another possbility is that susceptibility to Parkinson’s may somehow be linked to the absence of the sensation-seeking behavior that often underlies habits such as smoking and drinking.

The researchers in the current study evaluated the study subjects using standard psychological assessments. They found that individuals who developed the disease scored lower on the sensation-seeking scale and higher for depression and anxiety. The authors of the study raised the possibility that a “Parkinsonian personality” may underlie the susceptibility to the disease. At the biochemical level, this might be caused by low levels of the neurotransmitter dopamine.

What it Means: First of all, many experts point out that determining cause and effect in a retrospective study such as this one is extremely difficult and highly unreliable. And clearly no one would ever suggest that people try to reduce the hypothetical possibility of one disease by taking up behavior that would put them at greater risk of several other diseases.

So is the study bunk? Not necessarily. But this study is a perfect example of how scientific research doesn’t always translate into a useful message for consumers. While it is intriguing that there may be an association between risk taking and a lower incidence of Parkinson’s disease, there is nothing that non-scientists can do with that information.

This point is an excellent one to keep in mind when reading and listening to health news. Granted, there are some studies that are just flawed. But there are many more that represent the imperfect and ongoing search for scientific clues and links.

Indeed, most researchers are quick to point out when their conclusions must be treated cautiously or tentatively. (Truth to tell, you'll also find stories in the press that make scientific conclusions sound more definitive than they are.) It doesn’t mean the research is useless. But it might very well mean that there’s no news-you-can-use message for consumers.

From the Magazine:
12/17/2001 In Defense of Denial
07/19/1999 Eat Your Heart Out