Adults who regularly take ibuprofen are 38% less likely than nonusers to develop Parkinson’s disease, and the risk further decreases with higher frequency and duration of ibuprofen use.
Regular use of ibuprofen is associated with a significantly lower risk for Parkinson’s disease than is use of aspirin, acetaminophen, or other NSAIDs, according to the results of a study published in the March 8 issue of Neurology.
“Use of [NSAIDs] in general, and possibly ibuprofen in particular, has been shown to be related to lower Parkinson’s disease risk in previous epidemiologic studies,” the investigators wrote. Led by Xiang Gao, MD, PhD, Research Scientist at the Harvard School of Public Health in Boston, the group analyzed data of participants from larger cohort studies and conducted a meta-analysis of previous studies to determine if ibuprofen had a greater association than other analgesics with Parkinson’s disease risk.
The trial included 37,305 men from the Health Professionals Follow-up Study and 98,892 women from the Nurses’ Health Study, both of which used mailed questionnaires to gather information about NSAID use during a six-year follow-up. The investigators then calculated the relative risks for users and nonusers of each analgesic.
More Frequent and Long-Term Use of Ibuprofen Leads to Lower Risk of Parkinson’s Disease
Two hundred ninety-one cases of Parkinson’s disease (156 men) were identified during the follow-up. Users of ibuprofen had a 38% lower risk of developing Parkinson’s disease, compared with nonusers, after adjusting for age, smoking, caffeine intake, and other risk factors for Parkinson’s disease. In contrast, there was no significant relationship between acetaminophen, aspirin, or other NSAIDs and disease risk.
Acetaminophen and aspirin were not significantly associated with risk of Parkinson’s disease in a dose-response analysis. However, participants who reported taking one to two tablets of ibuprofen per week were 15% less likely to develop the disease; the risk decreased 60% for those who took three to four tablets per week, and 45% for those who took six or more tablets per week.
Participants with longer duration of ibuprofen use also tended to have lower Parkinson’s disease risk. Compared with nonusers, no change in risk was observed for participants with two to four years of cumulative ibuprofen use, but those with six to eight years of use lowered their risk by 26%, and those with 10 or more years of use lowered it by 57%, although this was not statistically significant.
In the meta-analysis of previous prospective studies and the current study, the pooled relative risk for ibuprofen users was 27% lower than for nonusers; aspirin users were 12% more likely to develop Parkinson’s disease. Use of other analgesics had no significant association with disease risk.
Ibuprofen’s Potential Neuroprotective Effects
“The association between use of ibuprofen and lower Parkinson’s disease risks, not shared by other NSAIDs or acetaminophen, suggests ibuprofen should be further investigated as a potential neuroprotective agent against Parkinson’s disease,” the authors wrote.
Although the exact mechanism for ibuprofen’s role in reducing Parkinson’s disease risk is unknown, the study’s findings suggest that ibuprofen has some neuroprotective effect not shared by aspirin or other commonly used analgesics. “Because the loss of brain cells that leads to Parkinson’s disease occurs over a decade or more, a possible explanation of our findings is that use of ibuprofen protects these cells. If so, use of ibuprofen could help slow the disease’s progression,” Dr. Gao said.
“There is no cure for Parkinson’s disease, so the possibility that ibuprofen, an existing and relatively nontoxic drug, could help protect against the disease is captivating,” senior investigator Alberto Ascherio, MD, DrPH, added.
Although the findings of this study are promising, the authors note that ibuprofen can have harmful side effects, such as gastrointestinal bleeding, and that investigation about whether the benefit of slowing the disease’s progression outweighs these potential risks is needed.
In an accompanying editorial, James H. Bower, MD, MSc, from the Mayo Clinic in Rochester, Minnesota, and Beate Ritz, MD, PhD, from the UCLA School of Public Health, said that there are many unanswered questions about the safety of using ibuprofen as disease prevention. “Every agent has well-recognized risks and the list for chronic ibuprofen use is a long one,” they wrote. “A clinical trial for ibuprofen, or perhaps a safer peroxisome proliferator-activated receptor g agonist, may be warranted.”