Spaceflights cause irreparable damage to astronauts’ health by accelerating the aging of their hematopoietic stem cells, which are responsible for a healthy blood supply and immune system. This is the conclusion of scientists at the Sanford Stem Cell Institute at the University of California, San Diego. They found that even short missions lead to DNA damage and the shortening of telomeres, a key sign of premature aging.
In a study published in the journal Cell Stem Cell, researchers used artificial intelligence-powered nanobioreactor systems to track cells during four SpaceX missions to the International Space Station. They found that after just 32-45 days in space, the cells lost their ability to regenerate, became more vulnerable to DNA damage, and showed telomere shortening—a clear indicator of accelerated aging.
“Space is the most severe stress test for the human body,” said Catriona Jamieson, director of the institute. She explained that microgravity and cosmic radiation trigger molecular processes that speed up the aging of stem cells.
The key changes found in the cells included excessive activity, depleted energy reserves, mitochondrial damage, and the activation of normally “silent” parts of the genome. These changes can lead to inflammation, reduced immune function, and an increased risk of diseases, including cancer. However, the researchers found a promising fact: when the damaged cells were placed back in a young and healthy environment on Earth, some of the negative changes began to reverse.
The authors believe their findings are of immense importance for the future. The discovery will not only help develop effective protective measures for astronauts on long-duration missions but also provide a better understanding of aging and disease mechanisms on Earth. The next steps will involve further experiments aboard the ISS and research to find pharmacological or genetic methods to counteract accelerated aging.
