MONDAY, May 5, 2008 (HealthDay News) -- People who use the painkiller ibuprofen regularly for five years may be less likely to develop Alzheimer's disease as they age, a new study suggests.
And more generally, people using the class of drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs) may have a decreased risk for Alzheimer's as well, although the link here is not as clear-cut as it is for ibuprofen.
But the findings don't put to rest a debate that has long simmered about the role of NSAIDs in the prevention or treatment of Alzheimer's, given the gastrointestinal side effects associated with long-term use of this class of painkillers.
"This discussion has been going on for a while," said William Thies, vice president of medical and scientific relations for the Alzheimer's Association. "This trial is big enough and the results are good enough that it may reopen the debate -- that we should do a prevention study with these medications."
But at this point, the conclusions aren't firm enough to start taking ibuprofen or any other NSAID to help ward off dementia, he said.
"Probably people shouldn't be taking these medications just to prevent Alzheimer's. The effect is too uncertain and the side effects are pretty well known," Thies said. "For those people who won't listen to this advice, they should be really careful to fill in their physician so he can track it with other medications."
Dr. Steven Vlad, lead author of the study and a fellow in rheumatology at Boston University School of Medicine, agreed, saying: "The big issue is that ibuprofen looks like it prevents Alzheimer's but all these drugs have well-known side effects and significant side effects, so the risk-benefit ratio is not clear at this point. Patients shouldn't go on ibuprofen to prevent Alzheimer's."
The findings are published in the May 6 issue of Neurology.
While so-called epidemiological studies have indicated some dementia prevention benefit with NSAIDs and ibuprofen, treatment trials have shown no benefits.
The new study involved five years of data on 50,000 U.S. veterans aged 55 and older who had a diagnosis of Alzheimer's. A control group included almost 200,000 veterans without an Alzheimer's diagnosis.
Overall, people who used NSAIDs long-term were at a lower risk of developing Alzheimer's -- about 25 percent lower. But the benefit was more pronounced with specific drugs.
The risk of developing Alzheimer's decreased the longer a person used ibuprofen, with those using the drug for five years more than 40 percent less likely to develop this dementia.
"It's not clear what the mechanisms are," Vlad said. It may have to do with reducing inflammation in the brain, reducing a component of the plaques which are a hallmark of Alzheimer's, or some as-yet unidentified process, he added.
"A clinical trial of ibuprofen for the prevention of Alzheimer's disease would be reasonable to get the risks and benefits," Vlad said. "There's also going to be ongoing research into developing drugs like ibuprofen without the toxicities."
A second study in the same issue of the journal, by U.S. researchers involved with the Cardiovascular Health Cognition Study, found that people with shorter limbs may have a higher risk of developing dementia.
Among women, greater knee height (measured from the sole of the foot to the front of the thigh) and arm span (the distance between fingertips) were linked with a decreased risk of dementia (16 percent decreased risk per 1-inch increase for knee height, and a 7 percent decrease per 1-inch increase in arm span).
Overall, women with the shortest arm spans were 1.5 times more likely to develop dementia, including Alzheimer's, compared with women who had longer arm spans, the study said.
Among men, only arm span was associated with a lower risk of dementia: a 6 percent decreased risk for every one-inch increase.
The researchers suggested that poor nutrition may have much to do with the possible link. According to the researchers, poor nutrition in early life and other factors could influence intelligence and levels of education and, eventually, risk of dementia.
In this study, men and women with longer measurements had had more years of education; height has also been linked with intelligence.
Visit the Alzheimer's Association for more on this brain disorder.