April 3, 2020
Many people take a daily baby aspirin to lower their risk of heart disease, stroke, colon cancer and other ailments. And some studies have suggested that a daily aspirin may lower the risk of memory decline and dementia. But a new analysis found that a daily aspirin did not slow the rate of age-related memory or thinking problems or lower the risk of developing Alzheimer’s disease.
“The scientific community is eager to find a low-cost treatment that may reduce a person’s risk” of Alzheimer’s disease and other forms of dementia, said study author Joanne Ryan, of Monash University’s School of Public Health in Melbourne, Australia. “Unfortunately, our large study found that a daily low-dose aspirin provided no benefit to study participants at either preventing dementia or slowing cognitive decline.”
The findings come from a large analysis involving 19,114 men and women, aged 70 and older, who were enrolled in a study called ASPREE, or Aspirin in Reducing Events in the Elderly. All were free of heart disease, dementia and other serious health problems at the start of the study.
Some took a 100-milligram daily baby aspirin, for an average period of 4.7 years. The others took a placebo pill. They received regular health check-ups, as well as tests of memory and thinking skills. Over the course of the study, 575 people developed dementia.
A daily aspirin did not reduce the number of cases of Alzheimer’s disease or other forms of dementia. Nor did aspirin reduce the incidence of mild cognitive impairment, a brain ailment that often progresses to full-blown Alzheimer’s disease. The findings were published in Neurology, the medical journal of the American Academy of Neurology.
“The scientific community is eager to find a low-cost treatment that may reduce a person’s risk” of developing Alzheimer’s disease, said study author Joanne Ryan, of Monash University’s School of Public Health in Melbourne, Australia. “Unfortunately, our large study found that a daily low-dose aspirin provided no benefit to study participants at either preventing dementia or slowing cognitive decline.”
It is possible that the study period, under five years, was not long enough to detect possible benefits for slowing memory decline or dementia risk. Those taking aspirin for longer periods, a decade or two, might show benefits for memory and thinking skills. “We will continue to examine aspirin’s potential longer-term effects by following up with study participants in the coming years,” said Dr. Ryan.
“What if it takes a decade or more for the aspirin effect to express itself?” asked doctors who wrote an editorial accompanying the study. “What if the aspirin-sensitive risk begins to accrue in midlife, long before participants were enrolled in ASPREE? Perhaps randomized clinical trials simply cannot be used to document benefits that emerge so slowly.”
It is also possible that some subsection of the patients in the study, but not all, benefited from aspirin.
Aspirin lowers level of inflammation, and increasingly it is believed that inflammation is involved in the onset of Alzheimer’s disease and other chronic ailments. Aspirin also thins the blood. For years, doctors have been prescribing low-dose aspirin to their patients to reduce their risk of heart disease and stroke.
Because aspirin can be beneficial to the heart, researchers have hypothesized, and smaller previous studies have suggested, that it may also be beneficial to the brain, possibly reducing the risk of dementia by reducing inflammation, minimizing small clots or by preventing the narrowing of blood vessels within the brain.
However, there are also possible risks to taking aspirin, including brain hemmorrhage and bleeding of the digestive tract. So anybody considering aspirin long-term should talk with their doctor first.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Joanne Ryan, PhD, Elsdon Storey, MB, DPhil, Anne M. Murray, MD, MSc, et al: “Randomized placebo-controlled trial of the effects of aspirin on dementia and cognitive decline.” Neurology March 25, 2020.
David S. Knopman, MD, and Ronald C. Petersen, PhD, MD: “The quest for dementia prevention does not include an aspirin a day.” Neurology, March 25, 2020