Media Advisory

Tuesday, June 20, 2023

Low-dose aspirin may increase risk of anemia in older adults

Data analysis from NIH-funded clinical trial reveals new insights


A recent follow-up analysis of data from an international, National Institutes of Health-funded clinical trial suggests daily low-dose aspirin increases the risk of anemia in people age 65 years and older by approximately 20%. Given these findings, older adults on low-dose aspirin and their care providers may want to consider periodic monitoring of red blood cells or hemoglobin. Anemia in older adults is associated with functional decline, increased fatigue, disabilities, depressive symptoms, and cognition problems.

Published in the Annals of Internal Medicine, scientists from the Aspirin in Reducing Events in the Elderly (ASPREE) study examined the effect of long-term low-dose aspirin use on incident anemia and the effect of aspirin on changes in hemoglobin concentration, as well as ferritin levels, as an indicator of iron deficiency. The researchers found that low-dose aspirin led to increased incident anemia in otherwise healthy older adults at enrollment, independent of major bleeding.

Previous ASPREE data analyses suggested daily low-dose aspirin does not decrease risk for dementia and cognitive decline; and that daily low-dose aspirin had no effect on healthy lifespan in older people.

ASPREE, a joint U.S. and Australian research project aimed at determining the effect of low-dose aspirin on survival without dementia or disability, began in 2010 and completed recruitment in 2014. It was a randomized, double-blind, placebo-controlled, primary prevention trial of daily 100 mg of aspirin in a population of healthy older people in the U.S. and Australia with a period of treatment averaging 4.5 years. The trial involving 19,114 people age 65 and older was distinctive for its size, methodological rigor, and high participant retention rate in both countries.


The following NIA experts are available to discuss specific findings of this paper:

  • Basil Eldadah, M.D., Ph.D., Supervisory Medical Officer
  • Evan Hadley, M.D., Ph.D., Division Director of Geriatrics and Clinical Gerontology

This research was supported by NIH National Institute on Aging grants U01AG029824 and U19AG062682.


McQuilten ZK, et al. Effect of Low Dose Aspirin versus Placebo on Incidence of Anemia in the Elderly: An Analysis of the Aspirin in Reducing Events (ASPREE) Randomized Controlled Trial. Annals of Internal Medicine. 2023; doi: 10.7326/M23-0675

About the National Institute on Aging (NIA): NIA leads the U.S. federal government effort to conduct and support research on aging and the health and well-being of older people. Learn more about age-related cognitive change and neurodegenerative diseases via NIA’s Alzheimer's and related Dementias Education and Referral (ADEAR) Center website. Visit the main NIA website for information about a range of aging topics, in English and Spanish, and stay connected.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit

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