Genetic traits may influence aspirin’s possible effects on dementia risk.
A new study suggests aspirin may be linked to a lower risk of dementia in older adults with certain genetic traits related to platelets. Researchers from Monash University in Australia examined whether a person’s genetic makeup could affect how aspirin influences dementia risk. The findings, published September 24 in Alzheimer’s & Dementia, point to a possible connection between platelet activity, aspirin use and brain health, although researchers say much more work is needed before any changes to medical advice can be considered.
The study used genetic and health information from more than 13,500 people who took part in the ASPREE trial, a large study of aspirin use among older adults. Researchers gave participants a genetic score based on traits linked to platelet counts and then compared dementia rates among people taking low-dose aspirin with those taking a placebo. Among people with the highest platelet-related genetic scores, about 1 percent of those taking aspirin developed dementia. The rate was 3.3 percent among those receiving the placebo. Researchers calculated that this represented about a 70 percent lower risk within that particular genetic group.
The finding is different from the overall results of the ASPREE trial, which did not show that aspirin prevented dementia across the broader study population. According to lead researcher Dr. Peter Fransquet of Monash University, the genetic analysis may have identified a smaller group of people who could respond differently to aspirin. The results do not mean that aspirin should be used by older adults as a way to prevent dementia. The study also found a serious downside. Major bleeding occurred in 4.4 percent of participants taking aspirin, compared with 2.1 percent of those taking the placebo. Bleeding is a known concern with aspirin, especially among older adults.
Researchers believe platelets may have a role in brain health beyond their familiar job of helping blood clot after an injury. Platelets also take part in inflammation and blood vessel activity. Some research has also connected platelet activity with processes involving amyloid, a protein associated with Alzheimer’s disease. Aspirin reduces the ability of platelets to become active and stick together. Researchers believe this could possibly affect blood vessel or inflammatory processes in people whose genetics give them certain platelet-related traits. However, this explanation has not been proven, and the study did not establish that aspirin directly prevents dementia through this pathway.
Dr. Thomas Holland, a physician scientist at Rush University, said the findings raise interesting questions about the role of platelet biology in dementia. He also cautioned that aspirin is not harmless and should not be started for dementia prevention without a discussion with a qualified health care professional. The researchers say the next step is to see whether the findings can be repeated in other groups of people. A separate clinical trial may also be needed to determine whether aspirin truly lowers dementia risk among people with the genetic profile identified in the study.
If future research confirms the results, genetic testing could eventually help doctors determine whether certain people are more likely to benefit from existing medicines. Such an approach could make dementia prevention more personalized rather than treating all older adults in the same way.
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