Anti-inflammatory pain relievers such as Ibupofren (Advil, Motril) and naproxen (Aleve) may delay the onset of Alzheimer's but do not prevent it, according to a new medical study.
Earlier studies indicated that such nonsteroidal anti-inflammatory drugs (NSAIDs), which include aspirin, could protect against Alzheimer's, a degenerative disease linked to inflammation in the brain.
The new research, published in the April 22 online issue of Neurology, the journal of the American Academy of Neurology, has shown the opposite effect, with NSAIDs increasing the risk of Alzheimer's by 66 percent.
The study involved 2,736 subjects with an average age of 75 who did not suffer dementia when enrolled. Followed over a period of 12 years, the group included 351 heavy users of ibuprofen or naproxen prior to enrollment, and 107 who became heavy users during the study.
At the end of the research, 476 patients had developed Alzheimer's or some form of dementia.
Researchers determined that heavy NSAIDs users had 66 percent greater chance of developing Alzheimer's or dementia than those with little or no NSAID use.
"A key difference between this study and most of those done earlier is that our participants were older," said study author John Breitner, of the Department of Veterans Affairs and the University of Washington in Seattle.
"It has been argued for some time that NSAID use delays the onset of Alzheimer's disease. It would follow that studies looking at younger people who use NSAIDs would show fewer cases of Alzheimer's, while in groups of older people there might be more cases, including those that would have occurred earlier if they had not been delayed," he added.
"This is one interpretation of the results, but other explanations are possible," Breitner cautioned, adding that further research was needed to understand why NSAIDs increased the risk of dementia.
Characterized by forgetfulness, agitation and dementia, Alzheimer's is caused by a massive loss of cells in several regions of the brain, driven by a buildup of plaques of amyloid protein. The disease occurs most frequently in old age.
An estimated 37 million people worldwide, including 5.3 million in the United States, live with dementia, with Alzheimer's disease causing the majority of cases, according to the World Health Organization (WHO).
With the aging of populations, this figure is projected to increase rapidly over the next 20 years.