Aspirin is an anti-inflammatory drug primarily used to relieve pain, fevers, and inflammation. It also has anti-clotting properties and has been widely used to prevent adverse cardiovascular events. Guidance has shifted in recent years to reflect updated evidence that the preventative benefits of low-dose aspirin do not outweigh the risk for bleeding in healthy older populations at low to moderate cardiovascular risk. Similarly, the potential effects on dementia prevention appear to be limited to those at high cardiovascular risk.
Aspirin has been tested in numerous high-quality, large-scale studies. Most meta-analyses of clinical trials and observational studies find no association between aspirin use and dementia risk, though some subpopulations may benefit. Our search identified:
Most studies have found that aspirin use does not meaningfully impact cognition and dementia risk in the general population [1; 2; 3; 4]. However, aspirin use has been linked with lower dementia risk in particular subpopulations. Evidence from two large cohort studies found that aspirin use was associated with meaningfully lower dementia risk in participants with coronary heart disease [5]. Protection from dementia was also observed in a trial including participants at high risk for cardiovascular disease [6]. Notably, risk reduction was only observed when aspirin was used for at least ten years. Some studies may have been too short to detect an effect on cognitive or dementia outcomes. Of the three large, long-term prevention trials for low-dose aspirin assessing cognitive outcomes, a potential benefit in women was only observed in the study with a follow-up longer than ten years [6; 7; 8]. Additionally, low-dose aspirin did not protect against stroke-related cognitive impairment in clinical studies [9; 10].
Overall, a low-dose aspirin regimen may help reduce dementia risk in individuals with cardiovascular disease or at high risk, but is unlikely to benefit other populations.
One observational study found that aspirin use was associated with a lower rate of cognitive decline in male patients with Alzheimer’s disease [11]. However, clinical trials with aspirin have not shown benefits on cognition or disease progression [12].
The primary safety risk associated with aspirin is bleeding, particularly in the gastrointestinal tract [13]. This risk increases with age, particularly in those over age 65, and is higher in men [14]. Due to the bleeding risk, aspirin has interactions with other blood thinner medications, as well as some herbal medicines, such as ginkgo, ginger, and ginseng [15]. Consuming alcohol also increases the risk of bleeding.
NOTE: This is not a comprehensive safety evaluation or complete list of potentially harmful drug interactions. It is important to discuss safety issues with your physician before taking any new supplement or medication.
Low dose aspirin is defined as doses between 75 to 100 mg/day. While most clinical trials have tested aspirin at a dose of 100 mg/day, the most common over the counter formulation is an oral tablet containing 81 mg of aspirin. The guidelines for use vary with age, bleeding risk, and cardiovascular risk [16]. It is not recommended for primary prevention in adults over age 70, but may be considered on an individualized basis for adults aged 40 to 70 at low bleeding risk and very high cardiovascular risk [17].
Full scientific report (PDF) on Cognitive Vitality Reports
For more information on the history, use, and safety see Drugs.com