Aspirin may slash dementia risk by 70% — but only if your genes are right

A new analysis from Monash University offers a compelling clue in the fight against dementia: low-dose aspirin may dramatically reduce dementia risk — but only in people with a specific genetic profile. Researchers analyzed data from over 13,500 participants in the ASPREE Trial and found that those in the top 20% of genetic scores linked to platelet count had a 70% lower relative risk of developing dementia when taking aspirin compared to a placebo. Previous studies found no overall protective effect, suggesting genetics may explain why aspirin works for some but not others.

The discovery points to platelet biology — not the usual Alzheimer's-linked genes — as a new avenue for dementia research. But there's a serious trade-off: the same high-risk genetic group saw major bleeding rates nearly double those on placebo, making the benefit-risk calculation far from straightforward.

By the Numbers:

• 70% lower relative risk of dementia in aspirin users with high platelet-count genetic scores
• 1% of aspirin users in that group developed dementia vs. 3.3% on placebo
• 4.4% of aspirin users experienced major bleeding vs. 2.1% on placebo
• ~446,500 Australians currently living with dementia; projected to exceed 1 million by 2065

Why it matters: This research opens the door to genetically personalized dementia prevention using a cheap, widely available drug. Confirmation in other populations and dedicated clinical trials are still needed before aspirin can be recommended for this purpose — especially given the bleeding risks involved.