When the four-member crew of Axiom-2 launched into space in May 2023 their 10-day mission was chock full of experiments aimed at understanding human physiology. Results from some of those experiments, now online at Aging Cell, highlight spaceflight as a unique model for studying aging as well as cellular resilience. The research sets the stage for testing potential anti-aging interventions for those of us who have no plans to travel in space.
Spaceflight exposes astronauts to a combination of environmental stressors such as microgravity, ionizing radiation, disruption in circadian rhythms and social isolation. Utilizing blood samples taken before, during and after the Axiom-2 mission, Buck researchers, along with collaborators at Weill Cornell Medicine in New York City and at King Faisal Specialist Hospital in Jedda, Saudia Arabia, came up with what they call Epigenetic Age Acceleration (EAA), a formula which determines how those stressors impact gene expression and biological age. On average, EEA increased 1.91 years by flight day 7. Upon return, biological age decreased in all crew members with older astronauts returning to pre-flight estimates and younger astronauts showing a biological age lower than pre-flight levels.
“These results point to the exciting possibility that humans have intrinsic rejuvenation factors that can counter these age-accelerating stressors,” said Buck associate professor, Director of the AI and Bioinformatics Core and senior author David Furman PhD, whose lab has the ability to recapitulate the effects of microgravity in cells and organoids. “Using spaceflight as a platform to study aging mechanisms gives us a working model that will allow us to move toward the ultimate goal of identifying and boosting these rejuvenating factors both in astronauts and in those of us planning on aging in a more conventional manner.”
The blood samples were investigated using 32 different DNA methylation-based clocks and the research was led by Buck postdoc and bioinformatician Matias Fuentealba, PhD, first author of the paper. Scientists observed that shifts in immune cell composition accounted for a significant portion of the observed age acceleration, driven largely by changes in regulatory T-cells and naïve CD4 T-cells. However, even after adjusting for cell composition, chronological age predictors showed acceleration during spaceflight. “The findings suggest that spaceflight induces rapid, yet reversible, epigenetic changes that are partially distinct from cell shifts,” said Furman, adding, “This positions spaceflight as a platform to study aging mechanisms and test geroprotective interventions.”
Furman is modeling microgravity in his lab utilizing organoids grown from heart, brain and immune cells to further understand the impact of spaceflight on different tissues. Patented technology from the Buck has been spun off into a company focused on building tools and assays for drug discovery and for consumers interested in intervening in the aging process.
CITATION: Astronauts as a Human Aging Model: Epigenetic Age Responses to Space Exposure
DOI: 10.1111/acel.70360
Additional Coauthors include Christopher Mason, JangKeun Kim, Jeremy Wain Hirschberg and Eliah G. Overbey, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, New York; and Bader Shirah, Department of Neuroscience, King Faisal Specialist Hospital & Research Centre, Jeddah, Saudia Arabia.
COI: David Furman is co-founder of Cosmica Biosciences. All other authors have declared no competing interests.
About the Buck Institute for Research on Aging
At the Buck, we aim to end the threat of age-related diseases for this and future generations. We bring together the most capable and passionate scientists from a broad range of disciplines to study mechanisms of aging and to identify therapeutics that slow down aging. Our goal is to increase human health span, or the healthy years of life. Located just north of San Francisco, we are globally recognized as the pioneer and leader in efforts to target aging, the number one risk factor for serious diseases including Alzheimer’s, Parkinson’s, cancer, macular degeneration, heart disease, and diabetes. The Buck wants to help people live better longer. Our success will ultimately change healthcare. Learn more at: https://buckinstitute.org
Journal
Aging Cell
Method of Research
Meta-analysis
Subject of Research
People
Article Title
Astronauts as a Human Aging Model: Epigenetic Age Responses to Space Exposure
Article Publication Date
11-Jan-2026
COI Statement
David Furman is co-founder of Cosmica Biosciences. All other authors have declared no competing interests