People who regularly use ibuprofen may be less likely to develop Parkinson's disease than those who do not, according to a report published in Neurology.
In a study of more than 136,000 men and women, researchers found that the more ibuprofen tablets people took each week, the lower their odds of developing Parkinson's, a disorder in which movement-regulating brain cells degenerate over time.
But the study found no connection between Parkinson's risk and other Non-steroidal anti-inflammatory drugs (NSAIDS), like aspirin or naproxen, or with acetaminophen.
"It's too early to recommend use of ibuprofen to prevent or treat Parkinson's disease," lead researcher Dr Xiang Gao, of Brigham and Women's Hospital, Boston, said.
Findings lay down groundwork
Instead, Dr Gao said, the findings lay the groundwork for clinical trials to look at whether the painkiller, which costs only a few cents per pill, might help slow Parkinson's progression.
"An association does not prove causation," said Dr James H. Bower of the Mayo Clinic in Rochester, Minnesota. "One possible explanation is that ibuprofen does protect against Parkinson's disease. That's what everyone would hope, that would be very exciting."
"But we're not there yet," he said.
Scientifically sound study
However he also praised the study, saying it is "very scientifically sound," and that the researchers' theory on why ibuprofen might be protective is plausible.
Unlike other NSAIDs, ibuprofen acts on a PPAR-gamma receptor, which, animal research suggests, may play some role in the Parkinson's disease process. That, Dr Gao's team says, offers one possible explanation for their findings.
The results are based on data taken from 98,892 female nurses and 37,305 male health professionals.
Starting in 1998 and 2000, participants were asked about their use of common painkillers. Over the next six years, about two out of every thousand study participants were newly diagnosed with Parkinson's disease.
Overall, Dr Gao's team found, people who regularly used ibuprofen (at least twice a week) were 38% less likely than non-users to develop Parkinson's during the study period with factors like weight, age and smoking and drinking habits taken into account.
There was also evidence that the risk dipped as ibuprofen intake went up. People who said they downed six or more tablets per week had the lowest Parkinson's risk versus non-users.
However, those figures are based on small numbers. Of study participants who developed Parkinson's, only 10 were taking six or more ibuprofen tablets per week at the outset. And only 13 were taking one to 5 pills per week.
Other possible connections
There could also be other explanations for the ibuprofen-Parkinson's connection, Dr Bower said.
Constipation and other gastrointestinal complaints can present early in Parkinson's development, he pointed out. So it's possible that some people in those early stages avoided ibuprofen because they thought the medication caused or worsened those symptoms.
Some studies have linked exposure to toxins such as pesticides and manganese to a higher Parkinson's risk.
(Reuters Health, Amy Norton, March 2011)