Many of us routinely use aspirin to decrease the risk of stroke from blood clots that form either on our heart valves or our carotid arteries. Some people also believe that aspirin also slows the progression of Alzheimer’s Disease (AD). However, a recent review in the journal Stroke suggests that the drug does not slow progression of the disease and may increase the risk for intracerebral hemorrhage (ICH).

"What we know is that there's no indication to prescribe aspirin in order to slow down cognitive decline, and there's a potential increased risk of hemorrhage, so if there's no clear cardiovascular indication, I think doctors should refrain from prescribing aspirin to Alzheimer's disease patients," said one of the study's authors, Edo Richard, MD, PhD.
For this analysis, researchers searched PubMed and the Cochrane Library for randomized trials up that investigated the effect of aspirin for AD and registered complications of aspirin therapy, including ICH. They found only 2 relevant trials, neither of which had shown an effect of aspirin on progression of cognitive decline. But doctors are sometimes tempted to prescribe aspirin to AD patients if there is any indication of vascular damage, he added. "That, I think, is not a good idea."

Approached for a comment on the study, Ronald C. Petersen, MD, PhD, director of the Mayo Alzheimer's Disease Research Center, Rochester, Minnesota, called the results "important," "well founded," and "timely," especially with the growing concern about microbleeds and microhemorrhages in AD patients. "The study raises awareness of this complicated issue of blood vessels, hemorrhages, and Alzheimer's disease," said Dr. Petersen.
He pointed out that it is possible aspirin may aggravate small bleeds in the brain. "If the micro bleeds are occurring because of a loss of integrity of the blood vessel wall, be it amyloid being deposited (a substance associated with causing AD) in the wall or whatever, the aspirin, being a blood thinner, would just increase the likelihood of a leak and a bleed," he added.
The results should help convince physicians not to "throw aspirin out there as a panacea, like water, with the idea that it's just aspirin so don't worry about it," said Dr. Petersen. "No, aspirin could be a concern in the right situation. On the other hand, if the person has cardiovascular risk factor where aspirin may very well be important as a prophylaxis, don't be dissuaded from giving it."