Can a Daily Aspirin Lower Dementia Risk? A New Clue, and a Big Catch
Monday, October 26, 2026
Headlines this weekend said low-dose aspirin was "linked to 70% lower dementia risk." That number is real, but it comes with an important "for whom" and a serious catch. Here's the plain-language version.
What happened. Researchers at Monash University in Australia went back to the ASPREE trial, a large study in which older adults, mostly 70 and up, were randomly given either 100 mg of aspirin a day or a placebo. The original trial found that aspirin did not lower dementia risk overall. This time, the team looked at genetic data from more than 13,500 participants to see whether aspirin worked differently in some people. It did in one group: among people in the top 20% for genes linked to platelet count (platelets are the blood cells that help clots form), about 1% of those taking aspirin developed dementia, compared with about 3.3% on placebo. But in that same group, serious bleeding was about twice as common on aspirin, 4.4% versus 2.1%. Everyone else showed no dementia benefit. The findings were published in Alzheimer's & Dementia. (Sources: Monash University; the study.)
Why it matters. It hints that one-size-fits-all prevention may miss people who could benefit, and it points researchers toward platelets as a new clue to how dementia develops. The signal wasn't tied to the best-known Alzheimer's risk gene, APOE4.
What it does not mean. The authors call this "hypothesis-generating": when you test about 1,800 genetic scores, some can look strong by chance, so it has to be confirmed in other studies and then tested in a trial built for it. There's no routine test today that tells you whether you're in this group. And the bleeding risk is real. The lead researcher said people shouldn't start aspirin to prevent dementia based on this study without talking to their doctor. If you already take aspirin because a doctor prescribed it for your heart, don't stop on your own either. We pulled the full picture together in a new guide: Aspirin and dementia: what the research says.
Try this today: start a "brown bag" list for your next checkup
Write down every pill you take, including over-the-counter ones like aspirin, ibuprofen, sleep aids and supplements, with the dose and how often. Or put the bottles in a bag and bring them along. Ask your doctor or pharmacist: "Does each of these still make sense for me, and do any of them raise my bleeding risk or affect my memory?" It's a five-minute job that can catch real problems. Our page on medicines that can affect memory lists common ones to ask about.
Thanks for reading, and have a good start to your week.
Read the original study: https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/alz.71817
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