Low-Dose Aspirin Could Reduce Dementia Risk in Certain People

One widely used pain reliever may influence dementia risk in very different ways depending on a person’s genetic makeup.

Researchers at Monash University found that low-dose aspirin was associated with markedly fewer dementia cases in older adults with one specific genetic profile. The results may help scientists look for more tailored ways to prevent dementia.

Dementia is an umbrella term for conditions that slowly impair memory, thinking, and the ability to handle everyday tasks.

Although aging is the strongest risk factor, genetics, cardiovascular health, and other biological changes can also play a role. At present, there is no simple medication recommended for healthy older adults to help prevent dementia.

The study appeared in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association. Scientists examined genetic data from more than 13,500 participants in the ASPREE trial, a large study that tested daily low-dose aspirin in older adults.

Previous findings from ASPREE showed no overall dementia-prevention benefit when all participants were analyzed together.

In the new analysis, researchers looked at whether genetics could alter aspirin’s effect. They developed genetic scores linked to several biological traits and found the clearest difference in people whose genes were associated with higher platelet counts. Platelets are small blood components that help the body clot when bleeding occurs.

In the top 20% of that platelet-related genetic score, about 1% of participants assigned to aspirin developed dementia, compared with about 3.3% of those given placebo. That amounted to roughly a 70% lower relative risk in the aspirin group.

Even so, aspirin came with a serious downside. Major bleeding occurred in about 4.4% of aspirin users in this genetic subgroup, versus 2.1% of those taking placebo. Because aspirin reduces platelet clotting, it can be useful in some situations but can also raise the risk of dangerous bleeding.

The effect was not connected to the best-known Alzheimer’s-related genes. Instead, it suggests that platelet biology may help explain why aspirin appears to affect dementia risk differently across individuals. The researchers now want to know whether the same pattern shows up in other populations.

The work is notable because it reanalyzed a large randomized trial with genetic data, but the result is still a subgroup finding rather than proof that aspirin prevents dementia in people with this profile.

The number of dementia cases in the subgroup was fairly small, and the higher bleeding risk is significant. A new trial designed specifically for this genetic group would be necessary before aspirin could be recommended for dementia prevention.

Source: Monash University.