Does Aspirin Protect Against Dementia? Study Reveals Surprise

Not everyone may benefit equally from aspirin in preventing dementia, as a new Australian study suggests that genetics may influence the drug’s response in older adults.

An analysis conducted by researchers from Monash University found that the risk of dementia decreased by 70% among participants belonging to a specific genetic group who took low-dose aspirin.

However, this result was accompanied by an increase in cases of severe bleeding, making it premature to consider aspirin as a preventive option for dementia, according to a report published on Science Daily.

The study was based on data from more than 13,500 participants in the ASPREE trial, which examined the benefits and risks of aspirin in older adults.

Researchers sought to determine whether genetic differences explain the varying effects of the drug on dementia risk.

The analysis focused on genes associated with platelet count, small blood components that play a key role in stopping bleeding.

Researchers classified participants according to genetic scores related to platelet count, then compared dementia rates between those who took aspirin and those who received a placebo.

Among participants in the top 20% of genetic scores, 1% of aspirin users developed dementia, compared to 3.3% in the placebo group. This equates to a relative reduction of approximately 70% in the risk of developing the disease.

However, the figures also revealed a concerning aspect: 4.4% of aspirin users in the same genetic group experienced severe bleeding, compared to 2.1% in the placebo group.

These findings highlight the importance of distinguishing between the relative reduction in dementia risk and the net benefit of treatment, which requires weighing the probabilities of prevention against potential risks, particularly in older adults.

Lead researcher Peter Francis, from the School of Public Health and Preventive Medicine at Monash University, said the results suggest that genetic characteristics may help identify individuals who could benefit from specific preventive interventions in the future.

He noted that previous trials had not found that aspirin prevents dementia when considering participants as a single group, but the new analysis indicates that its effects may vary among genetic groups.

Researchers also pointed out that the genetic signal they observed was linked to platelet biology and was not related to known genetic risk factors typically associated with Alzheimer’s disease and other forms of dementia. This could open a new pathway for understanding the biological mechanisms underlying the disease.

The results come at a time when there is growing need for more effective strategies for dementia prevention.

Dementia Australia estimates that around 446,500 people will be living with the disease in the country by 2026, with projections indicating the number will rise to over one million by 2065.

Nevertheless, researchers emphasize that the findings are still preliminary and need to be validated in other populations before being tested in a clinical trial specifically designed for individuals carrying the specific genetic profile.

Francis stressed that people should not start taking aspirin for dementia prevention based solely on these results, given the risk of severe bleeding.

If the findings are confirmed in the future, they could contribute to developing a more personalized approach to prevention, identifying individuals who are likely to benefit from treatment compared to those for whom the risks of taking it may outweigh the benefits.