The NASA article [1] gives a little more background, and offers another explanation: Bailey found Scott’s telomeres on the ends of chromosomes in his white

The NASA article [1] gives a little more background, and offers another explanation: Bailey found Scott’s telomeres on the ends of chromosomes in his white blood cells increased in length while in space. This could be linked to increased exercise and reduced caloric intake during the mission. [1] https://www.nasa.gov/feature/how-stressful-will-a-trip-to-mars-be-on-the-human-body-we-now-have-a-peek-into-what-the-nasa https://www.nasa.gov/feature/how-stressful-will-a-trip-to-ma...