An aspirin a
day does not keep dementia at bay
American Academy of Neurology
Taking a low-dose aspirin once a day
does not reduce the risk of thinking and memory problems caused by mild
cognitive impairment or probable Alzheimer's disease, nor does it slow the rate
of cognitive decline, according to a large study published in the March 25,
2020, online issue of Neurology®, the medical journal of the
American Academy of Neurology.
Aspirin has anti-inflammatory
properties and also thins the blood. For years, doctors have been prescribing
low-dose aspirin for some people to reduce their risk of heart disease and
stroke.
However, there are also possible risks to taking aspirin, including bleeding in the brain, so guidance from a doctor is important.
However, there are also possible risks to taking aspirin, including bleeding in the brain, so guidance from a doctor is important.
Because aspirin can be beneficial to
the heart, researchers have hypothesized, and smaller previous studies have
suggested, that it may also be beneficial to the brain, possibly reducing the
risk of dementia by reducing inflammation, minimizing small clots or by
preventing the narrowing of blood vessels within the brain.
"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."
The study involved 19,114 people who
did not have dementia or heart disease. A majority of participants were age 70
or older. They took thinking and memory tests at the start of the study as well
as during follow-up visits.
Half of the people were given daily
100 milligram low-dose aspirin while the other half were given a daily placebo.
They were followed for an average of 4.7 years, with annual in-person
examinations.
Over the course of the study, 575
people developed dementia.
Researchers found no difference
between those who took aspirin and those who took placebo in the risk of
developing mild cognitive impairment, dementia, or probable Alzheimer's
disease. There was also no difference in the rate of cognitive change over
time.
"While these results are
disappointing, it is possible that the length of just under five years for our
study was not long enough to show possible benefits from aspirin, so we will
continue to examine its potential longer-term effects by following up with
study participants in the coming years," said Ryan.
A limitation of the study was that only relatively healthy people were enrolled, and such a population may benefit less from aspirin than the general population.
The study was supported by the
National Institute on Aging, the National Cancer Institute and the National
Institutes of Health in the United States, the Australian National Health and
Medical Research Council, Monash University and the Victorian Cancer Agency.
Bayer, the maker of the drug, provided the trial drug and placebo but had no
other role in this trial.