Despite previous research suggesting that taking a low-dose aspirin once a day could help prevent dementia, a new large-scale study has found that aspirin has no effect on slowing down the rate of cognitive decline.
Carried out by researchers at Monash University, Australia, the new large-scale study looked at 19,114 participants, most of whom were over the age of 70, and who did not have dementia or heart disease at the start of the study.
Half of the participants were instructed to take 100-milligram low-dose aspirin every day, while the other half were given a daily placebo. All participants were asked to complete thinking and memory tests at the start of the study and during follow-up visits, with participants followed for an average of 4.7 years.
During this time, 575 people developed dementia, and 41 percent were classified as having clinically probable AD.
The findings, published online on Wednesday in Neurology, the medical journal of the American Academy of Neurology, showed that there was no difference between the participants who took a daily aspirin and those who took a daily placebo in the rate of cognitive change over time or their risk of developing mild cognitive impairment, dementia, or probable Alzheimer’s disease.
As aspirin has anti-inflammatory properties and thins the blood, doctors have already been prescribing it for a number of years to certain individuals as an easy, low-cost way to lower their risk of heart disease and stroke. As its effect on blood can be good for the heart, smaller studies have already been carried out to investigate whether taking aspirin could also help reduce the risk of dementia by minimizing small blood clots or by preventing the narrowing of blood vessels within the brain.
However, the current findings do not provide any evidence that aspirin reduces the risk of mild cognitive impairment, dementia, or cognitive decline.
“Worldwide, an estimated 50 million people have some form of dementia, a number that is expected to grow as the population increases, so the scientific community is eager to find a low-cost treatment that may reduce a person’s risk,” said study author Joanne Ryan, PhD. “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.”
“While these results are disappointing, it is possible that the length of just under five years for our study was not long enough to show possible benefits from aspirin, so we will continue to examine its potential longer-term effects by following up with study participants in the coming years,” said Ryan.