THURSDAY, April 14, 2005 (HealthDay News) -- Ibuprofen, one of the most popular over-the-counter pain relievers, may help prevent or delay the onset of Parkinson's disease, new research suggests.
Although promising, the finding would need to be confirmed in further studies before any changes are made to current practice, the researchers said.
"The results are still rather preliminary," cautioned senior study author Dr. Alberto Ascherio. His team presented their report Thursday at the annual meeting of the American Academy of Neurology in Miami Beach, Fla. "Except for our study, there is not much done yet in terms of looking at the risk of Parkinson's disease in people who use NSAIDs."
NSAIDs are nonsteroidal anti-inflammatory drugs, widely prescribed pain relievers that include such over-the-counter medications as Aleve, Advil and Motrin, as well as prescription drugs called cox-2 inhibitors. Two cox-2 inhibitors, Vioxx and Bextra, have been pulled off the market because of adverse effects on the cardiovascular system. Ibuprofen is found in both Motrin and Advil.
Parkinson's, a degenerative nervous system disorder, typically affects people over the age of 50. A steady loss of cells producing a powerful brain chemical, dopamine, leads to motor symptoms including trembling, slowness of movement and impaired balance. There is no cure for Parkinson's, but certain therapies can help control symptoms.
Recently, evidence of inflammation in the brains of people who have died of the disease has led to preliminary research on whether anti-inflammatory drugs like ibuprofen might help slow Parkinson's.
"There may be inflammatory changes in the Parkinson's brain, but they're not very overt," said Dr. Carlos Singer, an associate professor of neurology and director of movement disorders at the University of Miami School of Medicine. And he said it's still unclear how inflammation fits into the overall disease picture.
"It's unclear whether this inflammatory action is something that is just a consequence of the disease and not relevant to its progression, whether it could be a causal factor, or something in between, like an aggravating factor," said Ascherio, an associate professor of nutrition and epidemiology at the Harvard School of Public Health and an associate professor of medicine at Harvard Medical School.
A previous study conducted by the same group showed that people who used non-aspirin NSAIDs regularly had a lower risk of developing Parkinson's than nonusers. "We found a 45 percent lower risk of Parkinson's among men and women who regularly took NSAIDs," Ascherio said. "That was the only study of its kind and we wanted to reproduce the results, because you never know if it is true or not."
In their current effort, the authors looked at nearly 147,000 people who participated in an American Cancer Society study. During the follow-up period of about eight-and-a-half years, 413 of these participants developed Parkinson's.
The researchers found that people who regularly used ibuprofen were at 35 percent lower risk of developing the disease than nonusers. The results were similar in men and in women.
People who took fewer than two tablets a week had a 27 percent lower risk of developing Parkinson's, compared with nonusers. Those taking two to 6.9 tablets per week were at 28 percent lower risk, while daily users were at 39 percent lower risk.
People who had taken ibuprofen for longer periods of time also seemed to have a lower risk, but the effect was not statistically significant. Those who had taken ibuprofen for less than two years had a 22 percent reduced risk compared to nonusers; those who took ibuprofen for two to 4.9 years had a 21 percent reduced risk, while those taking it for five or more years had a 28 percent reduced risk.
The authors found no significant relationship between use of aspirin, other NSAIDs or acetaminophen (Tylenol) and the risk of developing Parkinson's.
The reason behind ibuprofen's potentially protective effect against Parkinson's is not yet known.
"The results are not totally consistent in terms of pointing to specific mechanisms," added Ascherio. "We found that ibuprofen was related to a lower risk, but other NSAIDs that supposedly act through similar mechanisms were not related."
The other NSAIDs were used by smaller numbers of people, so this apparent paradox may simply be explained by lack of study particpants. But it could also be something unique to ibuprofen. "This would be consistent with parallel work in Alzheimer's disease, and people realizing that all NSAIDs are not equal," Ascherio said.
Still, more research is needed, he added. First, his team needs to follow up on if, and how, ibuprofen might be different from other medications in its class.
Eventually, the researchers need to do a larger, randomized trial. "I don't think we are quite ready to know which drug and in what dose," Ascherio said. "We need to do a little bit more homework."
For more on Parkinson's, visit the National Institute on Neurological Disorders and Stroke.