Whether you just discovered your first grey hair or you’re a full-on silver fox, chances are you’ve wondered what’s causing those hairs to change colour. We asked board-certified hair expert and member of the International Society of Hair Restoration Surgery, Dr. William Yates, to give us all a lesson in the science of going grey.
#1: Stray Greys
So what actually causes us to go grey? “You have a bunch of pigment-producing cells just beneath the hair follicle, called melanocytes,” Yates explains. “Those cells give the hair its colour up until a genetic signal tells them to stop, which is when the hair turns grey, and eventually white.” In other words, a so-called “grey” hair is just what a hair looks like when it’s no longer being coloured by the melanocytes in your scalp.
#2: Gene Grey
Sadly, you have zero control over when greyness starts. “When exactly those melanocytes decide to shut off is determined on the day you’re conceived, and based 100 percent on your genes,” Yates says. Once that happens, you’ll start to notice your hair fading to grey from the roots—like a pen slowly running out of ink.
#3: Grey Anatomy
Your head hair isn’t alone in the journey of going grey. Body hair—whether it be on your chest, your back or your privates—typically goes grey slightly after the hair on your head (although your facial hair will probably be the first to go). As for which body part goes grey first? There’s really no rhyme or reason to it, so expect to find random greys in your armpit, bush or anywhere else, with little warning.
#4: Grey Is The New Black (Or Brown, Or Blonde)
According to a 2012 study, nearly 50 percent of all people have half a head’s worth of grey hairs by the time they’re 50 years old.
#5: Work Hard, Grey Hard
Everyone knows stress causes grey hairs—that’s why Obama ended his presidency with a full head of them, right? Only trouble is, everyone is completely wrong about that. According to Yates, the timing is simply a coincidence: “People just happen to go grey during some of the most stressful times of their lives—in their 30s or 40s—when they’re raising kids or working a tough job.” Which unfortunately means you cannot write off Just For Men as a work expense.
#6: 80 Greys Around The World
Interestingly, people of different races tend to go grey at different times. “Generally speaking, Caucasians go grey the fastest because they already have the least amount of melanin in their hair,” Yates explains. “Africans, on the other hand, go grey the latest.” According to an expert quoted by WebMD, Caucasians typically start to notice grey hairs around age 35, Asians start getting them in their late 30s, while African-Americans might not notice any at all until they’re in their mid-40s.
#7: Grey Expectations
If you really want to know when your locks will start losing their colour, it’s as simple as pulling out the photo album and seeing when your mum and dad started greying. As far as biology is concerned, you should go grey right around the same age.