Some years ago while I was still in secondary school, I had a roommate who was about 11 years of age, with much strands of gray hairs. I had wondered why a little boy could have strands of gray hair when as Africans, gray hair are correlated to being aged. At then I had just one strand of gray hair and I felt mine was fair.
Years later, my gray hairs began multiplying and I had lots of then at just the age of 25. Though people assumed me to be aged but my facial appearance showed how young I was.
Science of Gray
Our hair follicle have a pigment known as melanin, a chemical that give hair it's color. As one grows in age, the cells are known to die gradually. So the absence of the pigment called melanin, new hair strands grows lighter, taking different shades, from gray, silver then finally to white. So our hair follicle stops making color strands again.
Most people blame stress but it's our gene that dictates how early and how quick it happens. So if any of ones parents had gray before 30 or earlier in age, there's a possibility one of their children will have gray earlier.
How race play a role
On average, white people are know to have gray in their mid-30's, Asian start in their late 30 and African's in their mid-40's. So race also matters when determining the period a person grows gray.
Health problem that turn hair gray
There are few illness that could also cause gray hairs early in life. This include
deficiency in vitamin B¹²
some inherited tumour condition(tuberous sclerosis)
Vitiligo (A condition that destroy pigment making cell in the scalp)
Alopecia areata causes patches of hair (usually ones with color) to fall out. This can look like sudden graying because the hair that’s left is gray or white. When your hair regrows, it could be gray, white, or your normal color.
A findings giving insights for future research into how stress affects stem cells and tissue regeneration.
There are beliefs of negative effect of stress to cause gray hair, in Africa , once a person grows gray hair 5 or 10 years earlier than the supposed age, they are assumed to have been involved in labour that's stressful for some time. But this belief wasn't scientifically proven, until now when some group of scientist took on this research.
Hair color is determined by cells called melanocytes, which produce the pigment melanin. New melanocytes are made from melanocyte stem cells that live within the hair follicle at the base of the hair strand. As we age, these stem cells gradually disappear. The hair that regrows from hair follicles that have lost melanocyte stem cells has less pigment and appears gray.
So researchers took to carry on a study to determine if gray could be attributed to stress. The researcher was funded by NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and other NIH components. The findings appeared in Nature on January 22, 2020.
The research team, led by Dr. Ya-Chieh Hsu of Harvard University, used mice to examine stress and hair graying. The mice were exposed to three types of stress involving mild, short-term pain, psychological stress, and restricted movement. All caused noticeable loss of melanocyte stem cells and hair graying. Having established the link between grays and stress and tested them exploring several potential causes. Detail of the experiment can be read here. At the end of the experience, the team discovered sympathetic nervous system plays a critical role in stress-induced graying. Sympathetic nerves extend into each hair follicle and release noradrenaline in response to stress. Normally, the melanocyte stem cells in the follicle are dormant until a new hair is grown. Noradrenaline causes the stem cells to activate.
Under florescent labelling the cell migrate away from their reserve in the hair follicle after changing to melanocyte. So with no remaining stem cell, no further pigment was produced , thus all hair grown became white.
Hsu after the research was done said:
“When we started to study this, I expected that stress was bad for the body — but the detrimental impact of stress that we discovered was beyond what I imagined,After just a few days, all of the melanocyte stem cells were lost. Once they’re gone, you can’t regenerate pigments anymore. The damage is permanent.”
Though there are still debate that gray hair is affected by genetic and not stress. The recent discovery shows stress also causes strands of gray hair by affecting the stem cell which changes to melanocyte and moved away from their reserve in the follicle. So we can then conclude that , stress and genetic makeup are the obvious reasons behind gray hairs to occur earlier in age.