A 2014 study examined gene expression in experienced meditators before and after an intensive day of meditation practice. The results showed rapid changes in the expression of genes involved in inflammation, programmed cell death, and telomere maintenance. A control group that engaged in quiet non-meditative activities showed no such changes.
Telomeres, the protective caps on chromosomes, shorten with age and stress. Their maintenance is considered a marker of cellular aging. The finding that meditation influenced genes related to telomere function suggests a mechanism by which contemplative practice might slow biological aging.
This is among the more surprising findings in yoga and meditation research. The idea that a mental practice can alter gene expression within hours challenges conventional assumptions about the boundary between mind and body. The changes were not permanent rewrites of DNA but shifts in which genes were actively being expressed, a process called epigenetics.
Source: More Research on ashtanga.tech. Original research.

