NSAIDs -- nonsteroidal anti-inflammatory drugs -- include ibuprofen (brands include Advil and Motrin), naproxen (brands include Aleve), and Celebrex. Studies that compare people with Alzheimer's disease to people who don't have Alzheimer's disease have often shown that those without Alzheimer's are more likely to be long-term NSAID users.
That led to the large Alzheimer's Disease Anti-inflammatory Prevention Trial, in which healthy people were randomly assigned to take naproxen, Celebrex, or a placebo. The goal was to determine if taking NSAIDs could prevent Alzheimer's. Studies like this -- which compare active treatment to placebo and determine disease outcome -- are the only way to show whether a drug really helps.
But the study was stopped early after Celebrex was linked to an increased risk of heart attacks and strokes.
At the time, the researchers reported that taking naproxen or Celebrex for up to four years didn't slow age-related decline in mental function.
But researchers continued to follow the study participants after the study was halted. Now, an average of two years after the trial was stopped, follow-up results suggest that taking naproxen cuts the risk of developing Alzheimer's disease by two-thirds.
Celebrex also appeared to help brain function, though that finding could have been due to chance.
The findings were presented at the Alzheimer's Association 2009 International Conference on Alzheimer's Disease.
Timing Is Everything
Researcher John C. S. Breitner, MD, of the University of Washington in Seattle, says he was completely surprised by the results. If confirmed, they suggest that timing is everything, he tells WebMD.
Breitner says that it turns out that many of the people taking NSAIDs who developed Alzheimer's disease early on had undiagnosed mild cognitive impairment, or memory loss, when they entered the study.
"It would appear that NSAIDs are harmful to people who already have signs and symptoms of mental decline," he says. "For people with healthy brains, NSAIDs appear to protect against the development of Alzheimer's disease."
Nevertheless, Breitner isn't ready to recommend that people, even those at high risk of Alzheimer's disease due to family history, take naproxen in an effort to prevent mental function.
"The data are tantalizing, but there are known risks to taking NSAIDs long term -- chiefly, stomach bleeding and an increased risk of cardiovascular disease," he says. "We need more information on the drugs' effectiveness and then we need to figure out if the benefits outweigh the risks."
Miia Kivipelto, MD, PhD, of the Karolinska Institute in Stockholm, and moderator of the session at which the findings were presented, tells WebMD that she would not recommend healthy people take an NSAID to prevent Alzheimer's even if there are benefits.
"There are too many known side effects. It's not like diet and exercise, both of which have been shown to protect against Alzheimer's and do not carry risks," she says.