Can mental or emotional stress damage our DNA? An experiment has shown that the presence of gray hair means that the melanocyte stem cells in hair follicles – that ones that become melanocytes that give color to hair – have badly damaged DNA. In response, our body forces these DNA damaged stem cells into early maturity. No melanocyte stem cells means no melanoctyes, and no melanocytes means gray hair.
The experiment was conducted by dermatologist Emi Nishimura in 2004. She exposed mice (their hair also grays with age) to genotoxic stressors – things that can damage our DNA – such as chemotherapy drugs and x-rays. The hair of the mice turned gray, and as Nishimura said, “the stressed mice’s gray hairs and the cell populations in their follicles were indistinguishable from those of elderly mice, suggesting that genotoxic stress might drive natural graying as well.”
So what does all of this mean? Oncologist David Fisher says that while it’s very strong evidence that the things we encounter everyday – radiation from the sun, household chemicals, perhaps even the medicine we take – can all damage us at a genetic level, the experiment doesn’t prove that emotional stress can damage our DNA or induce premature maturation of our cells.
More importantly, the experiment shows that to some extent our body is capable of protecting itself from DNA-damaged cells by accelerating their aging. Fisher thinks that the experiment is a good starting point to find ways for our body to do the same to cancer cells – which are also DNA-damaged cells.
[via Science]
