What Causes Hair to Turn Gray?

What Causes Hair to Turn Gray?


Anyone who has watched a President who isn’t
dying their hair through their term in office knows stress might be a cause for gray hair. If you have teenagers, you’ve probably even
remarked to them the stress they cause you is making your hair turn gray, all the while
not fully appreciating the fact that you have hair in the first place…. In any event, the truth is going gray really
has to do with the production of pigment in your hair follicles. That production process can be altered by
several contributing factors, stress being one of them. To understand what makes our hair turn gray,
we need to first talk about what makes our hair grow and give it color. A person’s hair color is the result of pigments
known as melanin. Made from two amino acids (tyrosine and phenylalanine),
these pigments are produced by a specialized group of cells known as melanocytes. They do this through a process called melanogenesis. Melanocytes are found throughout our body
and the melanin they produce is what gives our skin, hair, and eyes their color. The melanocytes responsible for hair color
are found in the bulbs of your hair follicles. Even though there is a wide range of hair
and skin color, there are only two main types of melanin- eumelanin is what produces dark
browns and blacks, and pheomelanin produces reddish/yellow. How these cells blend together will determine
what color your hair will be. It isn’t fully known what makes the melanocytes
blend together in the ways they do, to make the specific hair color for each individual. What is known is that there appears to be
clear genetic factors. One gene, and its alleles responsible for
red hair, have already been identified; known as MC1R, this is also the same gene responsible
for red pigments in several other species, like cows. Once the specific formulation of melanin is
produced, their granules are transferred to adjacent keratinocytes, also found in the
bulbs of your hair follicles. Keratinocytes are what produce keratine, the
dead protein cells that make up our hair. Once a Keratinocyte undergoes its scheduled
death, it retains the melanin making our hair color what it is. Gray hair is the result of less melanin within
the keratin. The less melanin, the more gray your hair
will be. White hair has no melanin at all. There are a few different processes that can
make our hair turn gray. The one most people think of is the natural
graying that occurs as we grow older. As we age our melanocytes become inactive,
but are still present. The older we get, melanocytes decrease in
number. The result is less and less melanin, until
none are present. Thus, we slowly turn gray, and then our hair
turns white in the winter of our lives. In February of 2005, Harvard scientists proposed
a theory as to why melanocytes decrease as we age. They found that a failure of melanocyte stem
cells was the cause. These stem cells stop producing adequate numbers
of melanocytes to maintain our color. In 2009, scientists in Europe found another
contributing factor. They found that hair follicles produce small
amounts of hydrogen peroxide. As any teenager preparing for a concert knows,
if you expose your hair to hydrogen peroxide, it will make your hair lighter. Normally this small amount of hydrogen peroxide
is broken down by an enzyme called catalase. As we age, catalase production is reduced. The result is a build up of hydrogen peroxide,
which blocks melanin production by melanocytes. There are several other things that can cause
our hair to turn gray. The exact mediating factor of them isn’t fully
known. Some include: genetic defects; abnormal hormone
production like in the case of sudden or chronic stress; abnormal body distribution of melanin;
and climate factors can also cause graying, such as pollutants, toxins, and chemical exposure. As for stress, in 2011, the 2012 Nobel Prize
winner in Chemistry, Robert Lefkowitz, led a research group that discovered the mechanism
that could explain why stress causes graying. Stress causes a release of numerous neurotransmitters
involved in our fight or flight response. Normally the release of these neurotransmitters
is short lived and has very beneficial attributes- the ability to run from a chasing lion, or
avoid an oncoming car to name a couple. Long term production of these neurotransmitters,
however, can cause DNA damage. This damage was shown by this group to promote
aging, the growth of tumors, miscarriages, psychiatric conditions, and graying of hair. The time and speed at which you will gray
varies greatly. It’s determined by many, if not all, of the
factors we’ve discussed here, such as your genetic predisposition, chemical exposures,
and the levels of chronic stress throughout your life to name a few. Bonus Fact:
• The average scalp has 100-150 thousand hairs. Hair is so strong that if you made all of
your hair into a rope, it could hold 10-15 tons or about 3.5 ounces per strand. Hair also has the highest rate of cell division
in the body. It grows at .3mm per day on average, and 1
cm per month. Thankfully, each hair has its own life cycle. If it didn’t, instead of losing hair randomly,
we would molt. On that note, hair grows in three phases:
Anagen- The active growth stage (80-85% of hair is in this phase); Catagen- This phase
is also known as the transitional phase, when hair begins to stop growing; and telogen-
this phase is when hair growth is completely shut down and the fibers fall out (10-15%
of our hair is in this phase at any given time). After your hair goes through the Telogen phase,
Anagen begins again and voila! More hair!… For some people… (BACK TO SINGLE TEAR SHOT
FROM BEFORE) As you might have guessed from this, hair
length is completely controlled by the length of the anagen phase of your hair follicle. How long this period lasts is generally determined
mostly by genetics, but can also be affected by hormones, and even extreme stress, which
in some cases can cause the majority of hair on your body to rapidly transition to the
telogen phase and fall out. As to how, there is some chemical signal that
ultimately controls the exact growth cycle. However, it isn’t yet fully known what exactly
triggers the catagen phase beyond that, but once it is triggered, the outer part of the
root ends up being cut off from its nutrient supply (blood), as well as the cells that
produce new hair, thus your hair stops growing. This phase lasts about three weeks. As mentioned, next up comes the telogen phase
where the follicle is in a resting state and your hair is now a “club hair”, completely
dead down to the root. During this stage, these hairs are relatively
easy to pull out (as can happen while brushing/combing/washing your hair), but if they manage to last long
enough, they’ll eventually be pushed out by a new hair as the cycle begins again. Obviously hairs on your arms or legs have
a very different anagen period than hairs on your head, thus why your leg hair doesn’t
grow two feet long without trimming. Further, different people, thanks mostly to
their genetics, have differing lengths of the anagen period for a given body part compared
to other people. For the hair on your head, the average length
of the anagen phase is about 2-7 years. For your arms, legs, eyebrows, etc., this
phase usually lasts just 30-45 days. However, in extreme cases which are quite
rare, some people have anagen periods for their heads as small as most people’s anagen
phases for their arms and legs. For these people, their hair never naturally
grows more than a few inches long. The opposite is also true, with people whose
anagen phase can last decades for their scalp hair. Under normal circumstances, though, you can
get a rough estimate of how long your anagen phase is based on how long your hair grows
naturally without cutting on a given area. First, assuming your hair isn’t already as
long as it can get, measure your hair length, then exactly a month later measure it again
and note the difference. Now you have your growth rate (usually about
1 cm every 28 days or 1 inch every 71 days). So if, without cutting, the hair on your head
eventually grows 16 inches long max, then your anagen phase lasts: (inches*period per
inch). So using the average of 1 inch every 71 days,
(16 inches * 71 days/inch)=approximately 1136 days or 3.11 years. As you might have now guessed from the fact
that hair growth is completely controlled by what’s going on under the surface, within
your hair follicles, and that genetics and hormones are the primary things determining
hair growth length, which are in no way affected by shaving, contrary to popular belief, shaving
does not in any way alter your hair growth rate nor does it alter
the color of the hair.

100 thoughts on “What Causes Hair to Turn Gray?

  1. This is very interesting. I was told by my grandma and my mom that the first few years or so after I was born, I actually had a light brown – almost blond – hair as as baby. As I grew older, it turned black and has been my "default" hair color since.

  2. I met a girl once who had lost all her hair color during pregnancy. From head to toe, all her hair was white. It was beautiful.

  3. I have white hairs overnight from pain and stress.. You still sexy Simon hair or no hair.,but you do confuse me when I see your older videos without the facial hair

  4. dude, being bald is a gift. Dry with one sheet of kitchen towel… savings at the barber, and you know what you look like when you wake up in a daze at 4am to a ringing doorbell.. be happy dude, we are the lucky ones.

  5. You did not mention injuries, especially from animals. I developed a "skunk stripe" where a mockingbird took a bite of my scalp. My ex-mother-in-law has 4 from the canines of a dog. This is just two examples. I know many more people with white hair growing from damaged scalp.

  6. Simon, something has been bugging me since I was a child and I thought you could find the answer for me. There has been billions of people to live and die in the world, where are all of the remains?

  7. Does anyone else have hair that changed color from that at birth? Both my oldest child and I were born with very dark brown hair, then by the time we were both around 2-3 years old, our hair lightened to a light blond. And then by the time we were both around 9-10, our hair had darkened down again to a medium brown.

  8. You said shaving doesn't stimulate hair growth. But I can tell you that boys who are near shaving age get a better beard when they shave. If they just let "peach fuzz" stay on their face, it takes longer for a "real beard" to show up. If they shave the fuzz, it comes back as a thicker beard.

  9. Couldn't people just take whatever the chemical is that causes our hair color to be what it is, as a supplement so we don't have to have gray hair?

  10. I started picking out thick white hairs aged 14. I'm 48 and have been totally white-haired since my late 30's. If I take after my grandfather … I'll have giant eyebrows, huge hairy ears, and a Volvo station wagon soon.

  11. So Edgar Allan Poe was (partly) right when he wrote Descent into the Maelstrom about how fear turned the sailors hair white.

  12. because stupidity maybe be black or any dark shade but wisdom is always white or looks grey if you have some black hair left

  13. As far as your shiny top, Simon, just remember that grass never grows on a busy road. And thank you for another interesting video.

  14. Sy you dont need head hair you look great without it. The beard suits you. Can the next video be who and when was the umbrella/parasol invented.

  15. I found out gray hair is the perfect canvas for fun color semi permanent dyes! Never have I been happier to have gone gray. Put some pink, purple, or blue on that gray, it feels delightful!

  16. Simon, you're in good company. Dwayne Johnson. Vin Diesel. Ving Rhymes. If you want to go old school, Yul Brenner and Telly Savalas. All badasses.

  17. Stress/Trauma related hair loss is brutal. When my Dad died in February a grave deal of my hair fell out…almost all of it the little dark hair I have left. Now I have this hilarious looking 3" under layer of hair that makes me look like Anthony Coleman from the SNL Skit LOL.

  18. My hair doesn't go into the stopping stage, I have been growing my hair for nearly 2 years and it only keeps getting longer. My 2 sisters and my daugher both have long hair down their backs. I think mine will do the same

  19. I have a very good friend who never goes to a barber. Every 6 months he shaves his head like a marine. By 6 months his hair is to his shoulders. Yet he can go 5 days without shaving his face and you can barely tell.

  20. As someone who’s 31 and started balding at 20, people that whine about going grey used to annoy me. I developed coping strategies around 27 after I gave up and learned to not worry about it as much. After years from 20 to 27 of constant hats.

  21. In the moment of silence as Simon looks down and the image goes gray.. I said:"aww" poor thing. 😄
    Simon, you look great just the way you are!

  22. I'm 70 years old. No hair loss. My late brother was 72 with no hair loss. Sorry Simon, my brother and I won the no hair loss lottery.

  23. I dunno Why would I believe about hair from bald looking guy in the first place. Hehhehe I’m jus kidding bro ❤️

  24. A little consistency with your pronunciation would make your presentation more professional. And no, that doesn't mean you should be consistently wrong. For example: Follicle is not pronounced "Follicule". Another: Melanocytes can be pronounced multiple ways; however, you should pick one and stick with it over the course of a single presentation.

  25. On cutting not changing the color; the gray patches in mine are still small enough that I can still cut them to eliminate all gray. It grows back though …

  26. My dad always joked that "God created a few good heads, and the rest He covered with hair." Looks like I'll be joining the club sooner that I had expected. . .

  27. Simon, you’re so cool and legit, I didn’t even notice you’re bald.

    Keep it awesome, mon ami.

    P.S. The beard helps. 😉

  28. So then I guess the scalps phase dies earlier because of it grows faster and starts at birth vs a beard still growing past balding?

  29. You know all those wives tales about which family members hair balding affects you. It would be cool to show a bunch of bald guys and then ask them what there dads hair and their mothers dads hair was like. Those are the main two relatives that most people always think are a way to predict mens hair in the future. Curious if out of like 10 bald guys how many had a bald dad or the mothers dad was bald to see if there appears to be any truth to either of those you always hear. I am lightly receding so I wouldn’t be able to do the bald guy video. I will say my moms dad was fully bald and at 36 I just dont see me losing all my hair like him so I can kind of debunk the one about if your moms dad is bald you will be too but one person isn’t enough to conclude anything lol

  30. In Gorillas, mature, rather than old individuals are called "Silverbacks" because of age-related colour loss. I have noticed I now seem to get more respect from some people simply because I "appear" to be older than them. It seems to me that this colour loss might serve some social function.

  31. Genuine question: what is the story with "ginger phobia"? Why do so many people have a problem with red hair? Is it a cultural thing? Are certain hair colours revered or feared through the ages across different cultures?

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