For years, the evidence suggested aspirin did little to prevent dementia or memory decline. A major 2020 study of more than 19,000 older adults found no cognitive benefit of a daily aspirin after nearly five years of follow-up.
But now, new Australian research indicates there may be more to the story.
Researchers from Monash University found low-dose aspirin was linked to a 70 per cent lower risk of dementia among older adults with a particular genetic profile.
What did the study find?
The study, published in Alzheimer’s & Dementia, looked at genetic data from more than 13,500 older adults to see whether a person’s genes influenced the effect aspirin had on dementia risk.
The strongest finding was linked to genes that influence platelet count.
Among people in the highest 20 per cent for a platelet-related genetic score, one per cent of those taking low-dose aspirin developed dementia, compared with 3.3 per cent of those taking a placebo. That works out to around a 70 per cent lower risk.
There was a downside, however. Serious bleeding occurred in 4.4 per cent of people taking aspirin, compared with 2.1 per cent taking the placebo.
Why this matters
Dementia Australia estimates 446,500 Australians are living with dementia in 2026, with that number projected to rise to more than one million by 2065.
“Previous trials found aspirin didn’t prevent dementia when everyone was considered together,” lead author Dr Peter Fransquet, from Monash University’s School of Public Health and Preventive Medicine, said. “Our findings suggest there may be more to the story.”
Researchers found the genetic link wasn’t associated with the well-known risk factors for Alzheimer’s disease and dementia but with platelet biology instead.
“In people with this particular genetic profile, we saw substantially fewer cases of dementia among those taking aspirin,” Dr Fransquet said.
“It raises the possibility that genetics could one day help us identify who may benefit from a preventive treatment, rather than taking a one-size-fits-all approach.”
For now, researchers say the finding needs to be confirmed in other studies and eventually tested in a trial designed specifically for people with this genetic profile.
Dr Fransquet stressed the findings aren’t a reason to start taking aspirin. “People shouldn’t start taking aspirin to prevent dementia on the basis of this study without consulting with their doctor, particularly given the increased risk of serious bleeding,” he said.
“If it holds up, the fact that aspirin is already cheap and widely available could make personalised dementia prevention a real possibility.”
