The idea that regular consumption of aspirin can reduce the symptoms of dementia has been the source of much contention in scientific circles. Researchers behind a new large-scale study involving almost 20,000 patients are the latest to weigh in on this debate, with their multi-year investigation uncovering no evidence of therapeutic benefit when it comes to staving off this Alzheimer’s and other types of cognitive impairment.
Aspirin is an anti-inflammatory medication used to alleviate pain and fevers, but one of its other effects is to thin the blood. For this reason doctors have also prescribed it to treat cardiovascular disease to cut down on the risk of heart attack and stroke (though this brings its own risks, too). And some research groups have wondered if this could have benefits when it comes to the brain.
This could mean reducing inflammation in the brain, avoiding the narrowing of its blood vessels or cutting down on the formation of blood clots. One 2018 study conducted in mice found aspirin could help to limit the accumulation of amyloid plaques in the brain, which many consider to be a key culprit in the neurological degeneration associated with Alzheimer’s disease. However, human trials have been conducted to explore this mechanism in humans, with the drug demonstrating no beneficial outcomes.
The latest research was conducted by scientists at Australia’s Monash University, and throws considerable weight behind this school of thought. The study involved 19,114 healthy participants without dementia or heart disease, with most over the age of 70. Half were given a low-dose of aspirin each day and the other half a daily placebo, while all were made to complete thinking and memory tests before, during and after.
The researchers followed the participants for an average of 4.7 years and subjected them to annual examinations, with 575 subjects developing dementia throughout. The scientists observed no difference in the risk of developing cognitive impairment or dementia between those who took aspirin and those that didn’t, nor did they observe a difference in the rate of cognitive decline.
“Worldwide, an estimated 50 million people have some form of dementia, a number that is expected to grow as the population increases, so the scientific community is eager to find a low-cost treatment that may reduce a person’s risk,” said study author Joanne Ryan, PhD, of Monash University’s School of Public Health in Melbourne, Australia. “Unfortunately, our large study found that a daily low-dose aspirin provided no benefit to study participants at either preventing dementia or slowing cognitive decline.”
While describing the results as disappointing, the team notes a couple of drawbacks to the study. One is that it only involved healthy participants, and it is possible that these subjects may benefit less from aspirin than a general population. The other is the possibility that the study length, of just under five years, was not a sufficient period of time for aspirin to display its benefits.
“We will continue to examine its potential longer-term effects by following up with study participants in the coming years,” said Ryan.
The research was published in the journal Neurology.
Source: American Academy of Neurology