If telomere length reduction correlates with aging, then the flight twin (Scott) aged less rapidly. Not everyone agrees that telomere length is a reliable aging

If telomere length reduction correlates with aging, then the flight twin (Scott) aged less rapidly. Not everyone agrees that telomere length is a reliable aging indicator. Another really interesting result was in DNA methylation, a gene activity regulation process [1]. Scott's DNA methylation decreased during flight while his Earthbound twin's methylation increased during that time. After Scott's return to Earth, DNA methylation in both twins returned to baseline level. The last result puzzles me. [1] https://en.wikipedia.org/wiki/DNA_methylation https://en.wikipedia.org/wiki/DNA_methylation