Pain Drugs Don't Prevent Dementia, Studies Suggest

Author:  Hoi See Tsao

Institution:  Wellesley College
Date:  May 2007

Two studies conducted by researchers at Brigham and Women's Hospital and Johns Hopkins School of Medicine have shown that aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) do not protect memory or prevent dementia, as had been previously believed.

One study, published in the British Medical Journal, examined over 6,000 women, while the other, published in Neurology, investigated 2,000 people with family histories of Alzheimer's. Researchers gave participants either an NSAID, which could be low dose aspirin, naproxen or celecoxib, or a placebo, for up to 11 years.

Throughout the studies, the participants were given memory tests and routinely examined for signs of dementia. At the end of the 11 years, the researchers discovered no difference between the two test groups in terms of protection against Alzheimer's or cognitive decline.

When you injure yourself, the damaged tissue releases prostaglandins, which are some of the chemicals that make your nerve endings register pain and that cause inflammation. Prostaglandins are synthesized by the working cells in the damaged tissues using the enzyme cyclooxygenase 2 (COX-2). Aspirin and other NSAIDs inhibit COX-2, preventing cells from producing prostaglandins. Previous research on ibuprofen, another NSAID, had demonstrated that the drug was able to dissolve protein clumps in the brain that could lead to Alzheimer's.

"Unfortunately aspirin does not appear to give the protection that some scientists had hoped for given the potential links between dementia and heart disease," said Rebecca Wood, chief executive of the Alzheimer's Research Trust. However, she argued that one study provided some evidence that women taking aspirin exhibited greater verbal fluency than those who didn't take the drug, suggesting the need for further investigation on this effect.

Written by Hoi See Tsao