New research suggests that common blood-thinning medications, regularly prescribed to millions for heart rhythm disorders, may help slow the cognitive decline associated with Alzheimer's disease by improving blood flow to the brain.
The study, led by researchers at Karolinska University Hospital in Sweden, analyzed data from over 7,300 individuals diagnosed with atrial fibrillation and Alzheimer's. Participants were categorized based on their anticoagulant use: those on newer drugs like rivaroxaban, those taking the older medication warfarin, and those not on anticoagulants.
Results indicated that patients taking newer anticoagulants experienced a slower rate of cognitive decline compared to those on warfarin or no anticoagulant treatment. While the difference in cognitive function scores was modest after one year, researchers believe this effect could become more significant over longer periods.
Atrial fibrillation, a common heart rhythm disorder, is more prevalent in older individuals and those at risk for or already experiencing dementia. The condition itself is thought to increase the risk of dementia by up to one-third. Approximately 1.6 million people in the UK are prescribed blood thinners for atrial fibrillation.
Experts estimate that these findings could be significant for the roughly one million people in the UK currently living with dementia, of which Alzheimer's is the most common form. This number is projected to rise to 1.4 million by 2040.
Dr. Maria Eriksdotter, the study's lead author, stated that there are reasons to believe the treatment could positively impact cognition by enhancing blood flow and reducing minor brain damage. The study was published in the European Heart Journal.
Beyond cognitive function, patients on newer blood-thinning drugs also showed a lower risk of premature death, stroke, and fractures compared to those not receiving anticoagulant treatment. Warfarin was also associated with reduced risks of death, stroke, and blood clots, though it carried a higher risk of major bleeding.
However, the researchers cautioned that further studies are necessary before anticoagulants can be recommended for their potential benefits in Alzheimer's patients without atrial fibrillation. The observed cognitive benefits were specifically linked to newer types of blood thinners.
Previous research has also highlighted lifestyle factors in midlife that may help prevent dementia. A study from NYU Langone Health suggested that maintaining normal blood pressure, being free from diabetes, and not smoking between the ages of 45 and 65 could lead to approximately 13 additional years of dementia-free life.