When the stem cells that give your hair its color get worn out or change too early because of stress in the cells, they stop making pigment, and your hair turns gray permanently.
Evidence from Studies
Supporting (3)
Community contributions welcome
Hyperactivation of Sympathetic Nerves Drives Melanocyte Stem Cell Depletion
When mice are stressed, their nerves release a chemical that makes the hair color cells burn out too fast and disappear, making their hair turn gray. This shows stress can permanently damage the cells that give hair its color.
Mitochondrial deoxyguanosine kinase depletion induced ROS causes melanocyte stem cell exhaustion and hair greying
When tiny power plants in hair stem cells break down, they make too much harmful gunk (ROS), which kills the cells that give hair its color. When scientists blocked this gunk, the hair kept its color — proving that this gunk causes gray hair.
Oxidative Stress in Ageing of Hair
As we age, our hair turns gray because harmful molecules called free radicals build up and damage the cells that give hair its color. This study shows that these damaging molecules are more common as we get older and that they likely cause the color-producing cells to stop working.
Contradicting (0)
Community contributions welcome
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.