Low-dose aspirin was linked to a 70 percent lower relative risk of dementia among older adults with a specific genetic profile tied to platelet count, according to a new study. The finding raises the possibility of a more personalized approach to dementia prevention.
The study, published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, analyzed genetic data from the ASPREE Trial, screening genetic scores in more than 13,500 participants to examine whether a person's genetics influence how much aspirin lowers dementia risk. The strongest signal was tied to genetics that influence platelet count.
Among participants in the top 20 percent for a platelet count genetic score, just 1 percent of those taking aspirin developed dementia, compared with 3.3 percent of those on placebo—a roughly 70 percent lower relative risk. But aspirin also raised the risk of serious bleeding in this same group, with major bleeding occurring in 4.4 percent of aspirin users compared with 2.1 percent on placebo.
Earlier trials had found that aspirin didn't prevent dementia when all participants were considered together, without accounting for genetic differences. Platelet activation and aggregation had previously been linked to dementia risk, but the role of overall platelet count specifically had remained unclear. Notably, the genetic signal identified here wasn't connected to genetic risk factors already established for Alzheimer's disease and dementia, pointing instead toward platelet biology as an avenue worth investigating.
"Our findings suggest there may be more to the story," said Peter Fransquet, lead author of the study and research fellow at Monash University's School of Public Health and Preventive Medicine. "In people with this particular genetic profile, we saw substantially fewer cases of dementia among those taking aspirin. 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."
The researchers' next steps are confirming the finding in additional studies and eventually testing it in a clinical trial designed specifically for people who share this genetic profile — work that could make personalized dementia prevention a realistic option given the broad availability of aspirin.
Data from Monash University