Scientists have long thought that grey hair may be linked to emotional stress. But while that connection feels pretty well-known, I, for one, was surprised by a recent paper linking the pale strands to cancer-related stressors. According to study leader Prof Emi Nishimura, whose work was published in Nature Cell Biology, the research “reframes hair greying and melanoma not as unrelated events, but as divergent outcomes of stem cell stress responses”. Grey hair might reflect a protection against DNA damage The researchers were looking at melanocyte stem cells (McSCs) in mice when they found the apparent link. McSCs, which are responsible for producing hair pigment, only quit and allow hair to turn grey in the event of “DNA double-strand breaks”, or when both sides of the DNA structure are broken. But they kept self-renewing and didn’t form sacrificial grey hairs when affected by other stressors, like some carcinogens and UV light, even when their DNA was damaged. That appeared to allow mutations to keep building and possibly even cloning as the McSCs reproduced, which the …