Study: Taking low-dose aspirin daily doesn’t lower dementia risk

50 million people worldwide are estimated to have dementia

For years, doctors have prescribed a low-dose aspirin regimen to some people to help reduce the risk of a heart attack. But the same benefits aspirin offers for heart disease and stroke have not been found for lessening the risk of cognitive decline, according to a recently published study.

Researchers theorized that because aspirin, which is anti-inflammatory and thins the blood, has heart benefits, it may also be beneficial to the brain.

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It was thought that aspirin could possibly lower the risk of dementia by lowering inflammation, reducing small clots or by stopping the narrowing of blood vessels within the brain, according to a press release from the American Academy of Neurology. The professional society published the findings in the online issue of its medical journal "Neurology."

The study’s theory, however, has not been realized.

“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,” study author Joanne Ryan, Ph.D., of Monash University’s School of Public Health in Melbourne, Australia, said in a statement.

“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,” she said.

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The study involved 19,114 people, the majority of which were age 70 or older. Participants, half of which were given a 100 milligram low-dose aspirin daily and the other half a placebo each day, did not have dementia or heart disease.

In the beginning and over the course of the 4.7 year study, participants took thinking and memory tests. In-person examinations were conducted yearly.

Ultimately, 575 people developed dementia.

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Researchers discovered no difference in the risk of developing mild cognitive impairment, dementia or probable Alzheimer’s disease.

“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,” study author Ryan said.

Only relatively healthy people enrolled in the study, which was a limitation. A healthy population may benefit less from aspirin than the general population.