The colour of our hair is created by the pigment-producing cells, referred to as melanocytes, situated in every hair follicle. Within the means of producing the pigment for our hair, these cells additionally produce another chemical substances, certainly one of which is hydrogen peroxide (sure, the stuff that bleaches your hair). After we’re younger, our our bodies additionally produce enzymes to neutralize that hydrogen peroxide and different free radicals so our hair retains rising in with shade. As we age, nonetheless, these neutralizing enzymes grow to be much less energetic than they as soon as have been, which implies that hydrogen peroxide begins to construct up and sap shade from our hair, leaving it a stunning shade of grey—and, finally, white, as soon as the strand has misplaced all its pigment.
Though most grey is said to a pure a part of the ageing course of, a big environmental issue is UV publicity, which might speed up hair ageing. One research—on mice, not people—demonstrated that not solely did UV publicity produce grey hairs, nevertheless it additionally decreased the diameter of the hairs and shortened the shafts of the roots. To be extra particular, publicity to UVA rays (these longer wavelengths) damages hair pigment, whereas UVB publicity (shorter wavelengths) damages hair proteins, particularly keratin. So daylight, which carries each UVA and UVB, is a double-whammy for hair injury.
Along with UV publicity, different life-style components contribute to going grey, like smoking, anemia, poor diet, low B nutritional vitamins, and untreated thyroid situations, says Hadley King, MD, a dermatologist primarily based in New York Metropolis. Genetics also can play a task; in case your dad and mom went grey at a youthful age, you in all probability will too.
One contributing issue that may be a bit extra in our management is stress. Scientists discovered that the physique’s “combat or flight” response can contribute to turning hair grey. Keep in mind these pigment-producing cells, the melanocytes? If you’re below stress, you launch a hormone referred to as norepinephrine, which principally causes your physique to enter overdrive—and burn by way of stem cells at a a lot quicker fee. Which means that, as your hair’s pigment-producing melanocytes die off (they sometimes reside about 3 to five years), there aren’t sufficient energetic stem cells to switch all of them… and a few hair begins to develop in with out pigment, i.e. flip grey.
Is reversing grey hair potential?
Possibly, particularly when you’ve simply found your first strands of silver. “We all know that in durations of stress, particular person hairs in your head can go grey. After which they will flip again as soon as the stressor is eliminated,” says James O’Sullivan, Ph.D., a postdoctoral analysis affiliate in developmental biology and cell metabolism, who has been concerned in analysis on the subject.