NSAIDs do not prevent Alzheimer's disease or other forms of dementia

A new study shows that nonsteroidal anti-inflammatory drugs (NSAIDs), such as the pain relievers ibuprofen and naproxen, do not prevent Alzheimer's disease or other forms of dementia.

Instead, the risk of developing dementia in the study's very elderly population (most were over age 83 when they developed dementia) was 66 percent higher among heavy NSAID users than among people who used little or no NSAIDs, according to research published online today in Neurology ®, the medical journal of the American Academy of Neurology.

Researchers identified 2,736 members of Group Health, an integrated healthcare delivery system, who did not have dementia when they enrolled in the study at an average age of 75. The investigators then followed these people for 12 years to see if they developed Alzheimer's or other forms of dementia. They checked Group Health pharmacy records for NSAIDs (tracking both prescriptions and over-the-counter use) and also asked participants about their use of NSAIDs.

Of the participants, 351 people had a history of using NSAIDs heavily at the study's start, and another 107 became heavy NSAID users during the follow-up period. Heavy use was defined as having prescriptions for NSAIDs at least 68 percent of the time in two years.

During the study, 476 people developed Alzheimer's disease or dementia. The risk of developing dementia among heavy NSAID users was 66 percent higher than among people with little or no NSAID use.

"NSAIDs are useful for relieving pain from conditions including arthritis," said study author Eric B. Larson, MD, MPH, executive director of Group Health Center for Health Studies. "Although we hoped to find a protective effect, there was none. Thus, for this age group, there's no basis for taking NSAIDs to prevent Alzheimer's disease. Our study in this quite elderly population showed more risk of dementia with NSAIDs, especially when used heavily."

The study suggests a need to re-interpret earlier findings that suggested NSAIDs can prevent or delay the disease. Why the discrepancy?

"A key difference between this study and most of those done earlier is that our participants were older," said lead study author John C. S. Breitner, MD, MPH, University of Washington professor of psychiatry and head of the Division of Geriatric Psychiatry at the VA Puget Sound Health Care System. "It has been argued for some time that NSAID use delays the onset of Alzheimer's disease. If so, studies of younger NSAID users would show fewer Alzheimer's cases, while groups of older people might show more cases, including those that would have happened earlier if they had not been delayed."

"This is one interpretation of the results, but other explanations are possible," cautioned Breitner. "We must not ignore our main finding: increased risk of dementia in the NSAID users. We need further research to understand that more clearly."