This website discusses uses of aspirin not approved by the Food and Drug Administration.

There are many causes of dementia, including neurological disorders such as Alzheimer's, Parkinson's and Huntington's disease, as well as blood flow- related (vascular) disorders such as multi-infarct disease; the latter type of dementia is called "vascular" or "multi-infarct dementia". (Cleveland Clinic online fact sheet, http://www.cchs.net/health/health-info/docs/2300/2340.asp?index=9170)

Aspirin's proven anti-thrombotic and anti-inflammatory effects may be responsible for any potential neurological/cognitive benefit that may accrue from cardiovascular therapy.

While preliminary data on aspirin and cognitive function is exciting for those already on a physician-directed cardioprotective regimen, additional research is needed. Nevertheless, research on aspirin in the treatment of dementia suggested a link more than 15 years ago and subsequent research supports a potential neurological/cognitive benefit for aspirin:

A 1989 study showed that low-dose aspirin (325 mg daily) may slow the progression of multi-infarct dementia. Those taking aspirin stabilized or improved three-to-one over the controls, with significant improvement in cerebral blood flow and cognitive performance. There was also improvement in quality of life and independence. (Meyer et al. "Randomized Clinical Trial of Daily Aspirin Therapy in MID," Journal of the American Geriatric Society (1989) 37:549.)

Additional evidence comes from another randomized, placebo-controlled intervention study in 400 patients who had been judged to be at high risk of cardiovascular events (a sub-group of the Thrombosis Prevention Trial (TPT)). These patients had been on aspirin, warfarin, both or neither for five years. The results provide tentative evidence that anti-thrombotic medication may improve cognitive function. (Richards M, Meade TW, Peart S et al.”Is there any evidence for a protective effect of anti-thrombotic medication on cognitive function in men at risk of cardiovascular disease? Some preliminary findings.” Neurol Neurosurg Psych 1997; 62:269-72.)

A meta-analysis of 15 studies published between 1966 and 2002 concluded that NSAIDs -- such as aspirin -- may lower the risk of developing Alzheimer's disease. The analysis found that people who took the drugs for two years or longer seem to derive the greatest benefit. (Etminan et al, British Medical Journal, July 18, 2003)

The possibility that aspirin might be of benefit in Alzheimer's disease has also been raised in the Baltimore Longitudinal Study of Ageing. Amongst subjects with two or more years' use of aspirin, the relative risk of Alzheimer's disease was reduced by about 60%. The authors draw the tentative conclusion that aspirin may reduce the inflammatory process in AD. A study of 50 elderly twins led to a similar tentative conclusion. (Stewart WF, Kawas C, Corrada M, Metter EJ. Risk of Alzheimer's disease and duration of NSAID use. Neurology 1997;48:626-32.; Brietner JC, Gau BA, Welsh KA et al. Inverse association of anti-inflammatory treatments and Alzheimer's disease : initial results of a co-twin control study. Neurology 1994;44:227-32.)

In addition, a Harvard study involving 142,902 health professionals showed that regular use (2 or more times per week) of non-aspirin OTC NSAIDs was associated with a significant 45 percent lower risk of developing Parkinson's disease compared to non-regular users. A similar (but statistically non- significant) risk reduction was found in those who took two or more aspirin daily (those who took less aspirin also showed a lower risk of Parkinson's disease, though the trend was not significant). (Chen et al, Archives of Neurology, August 18, 2003)