Plate Nº 77 · recorded October 10, 2026
Health & Medicine ResearchReported finding
Aspirin cut dementia risk by 70% in one genetic group, study finds
A Monash genetic analysis of 13,500 older adults links low-dose aspirin to 70% lower dementia risk in one genetic group — alongside a doubled serious bleeding risk.
By Marcus Bennett3 min read661 words
In brief
- Aspirin was associated with a roughly 70% lower relative dementia risk among participants in the top 20% of platelet-related genetic scores.
- In that group, 1% of aspirin users developed dementia versus 3.3% on placebo.
- Major bleeding rose to 4.4% with aspirin versus 2.1% with placebo.
- The study analyzed genetic data from more than 13,500 ASPREE trial participants.
- Dementia Australia projects over 1 million Australians with dementia by 2065, up from 446,500 in 2026.
Low-dose aspirin was linked to a 70% lower relative risk of dementia in older people carrying a particular genetic profile, according to a new genetic analysis from Monash University — but the same group also faced a doubled risk of serious bleeding.
The study, published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, analyzed genetic data from more than 13,500 participants in the ASPREE trial (Aspirin in Reducing Events in the Elderly). Researchers screened genetic scores across the cohort to test whether a person's genes change how aspirin affects dementia risk.
The strongest signal came from genes that influence platelet count — the tiny blood cells that help clotting. Researchers ranked participants by platelet-related genetic scores and split them into tiers.
What did the numbers show?
Among participants whose genetic scores fell in the highest 20%:
- Only 1% of those taking low-dose aspirin developed dementia, compared with 3.3% of those on placebo.
- That gap translates to roughly 70% lower relative risk associated with aspirin use.
- But major bleeding occurred in 4.4% of the aspirin group versus 2.1% of the placebo group.
The bleeding finding matters. It means any potential preventive benefit comes with a real safety trade-off, and it is one reason the researchers urge caution about the results.
Why did earlier trials miss this?
Lead author Dr. Peter Fransquet, a research fellow at Monash's School of Public Health and Preventive Medicine, said the findings suggest aspirin's effect on dementia depends on who is taking it.
"Previous trials found aspirin didn't prevent dementia when everyone was considered together," Fransquet said. "Our findings suggest there may be more to the story. In people with this particular genetic profile, we saw substantially fewer cases of dementia among those taking aspirin."
In other words, averaging everyone together may have hidden a benefit that exists only in a genetically defined subgroup. Fransquet said this raises the possibility that genetics could one day help doctors identify who would benefit from preventive treatment, rather than taking a one-size-fits-all approach.
What does this mean for platelet biology?
Scientists already knew that platelet activation and aggregation — the process by which platelets stick together to form clots — have some link to dementia. The role of a person's overall platelet count has been far less clear.
The new result points in that direction, and away from familiar suspects.
"What's particularly interesting is that the signal wasn't linked to the established genetic risk factors for Alzheimer's disease and dementia," Fransquet said. "Instead, it's pointing us towards platelet biology and gives us a new avenue to investigate."
The researchers now plan to confirm the finding in other studies and, ultimately, to test it in a clinical trial designed specifically for people with this genetic profile.
How big is the problem?
Dementia Australia estimates 446,500 Australians are living with dementia in 2026, and projects the number will exceed 1 million by 2065. Any tool that could sharpen prevention — especially one built on an inexpensive, widely available drug like aspirin — carries substantial public health interest.
Should people take aspirin to prevent dementia?
Not on the basis of this study, the researchers stress. The result comes from a genetic analysis of an existing trial, not a trial designed to test this specific question. It requires replication and a dedicated clinical trial before anyone can say aspirin prevents dementia in this group.
"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," Fransquet said. "If it holds up, the fact that aspirin is already cheap and widely available could make personalized dementia prevention a real possibility."
Publication details: Peter D. Fransquet et al., "Platelet count polygenic scores may modify the effect of aspirin in primary prevention of dementia," Alzheimer's & Dementia (2026). DOI: 10.1002/alz.71817
via Medical Xpress (Source)
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