The Science Behind Gray Hair
The Science Behind Gray Hair
Author: Jenna White | San Francisco Hairstylist
March 31st, 2022
March 31st, 2022
Gray hair is a visible sign of the natural course of aging that affects all populations. It occurs due to a loss of melanin, a pigment found in the skin, eyes and hair. Today's methods of combating gray hair consist of coloring it. However, the medical community is becoming confident that there could be ways to slow the process of going gray through new forms of medicine.
A quick note before diving into this topic. The word "gray" has different spellings. In American English it is commonly spelled "gray" and in British English it is commonly spelt "grey". I'll use "gray" throughout most of this post, except in the instance of publication titles.
A quick note before diving into this topic. The word "gray" has different spellings. In American English it is commonly spelled "gray" and in British English it is commonly spelt "grey". I'll use "gray" throughout most of this post, except in the instance of publication titles.
Some History on Hair Dye
In the mid-1800s, English chemist William Henry Perkin made the first non-natural dye, with natural hair dyes being solutions like henna. According to an article published by The Atlantic titled "Hair Dye: A History", Perkin "serendipitously synthesized the first non-natural dye: Starting with coal tar, he was hoping to produce the malaria drug quinine, but instead created mauve. His discovery revolutionized the textile industry and launched the petrochemical industry. Natural dyes just didn’t have the staying power and vivid colors of the dye Perkin created. Never before had such a steadfast dye been found". Perkin's discovery was the catalyst for today's modern hair dyes. However, now coal tar dyes are uncommon and need to be approved by the FDA before entering the market due to a rise in allergic reactions and eye injuries. Hairstylists plus consumers currently have safer options for coloring gray hair. Statista cites that "the global market for hair coloring reached over 29 billion U.S. dollars in 2019 and is expected to increase beyond 40 billion U.S. dollars by 2023".
Why does our hair turn gray?
All hair strands with color have varying amounts of pigments known as melanin. Melanin is a dark brown or black pigment. The amount in the strand determines how light or dark your hair appears. Melanin is also responsible for eye and skin color, as well as and your skin’s tanning response to the sun. Melanocytes are cells that control the production of melanin during a process that happens below the scalp's surface. Over time, the melanocytes in your hair can die, which results in your strands turning grey, and eventually white. Interestingly, the loss of melanocytes in the hair tends to occur earlier than the loss of those in the skin.
Are there differences in the way men versus women go gray?
Yes. In men, gray hair typically begins at the temples and sideburns, then spreads to the top of the head, and then to the back. In women, gray hair starts at the root area around the hairline framing the face, and then moves towards the top of the head.
When will I go gray?
Ethnicity plays a factor in whether you will go gray, and when. According to WebMD "Typically, [Caucasians] start going gray in their mid-30s, Asians in their late 30s, and African-Americans in their mid-40s. Half of all people have a significant amount of gray hair by the time they turn 50. A [Caucasian] is considered to be prematurely gray if their hair turns gray by age 20; gray before 30 is early for African-Americans". Seeing if and when your parents and grandparents have hair that turns gray may give you the best idea of when your hair could turn gray.
Aside from genetics, what are the causes of gray hair?
Stress
The science community is still working on the exact mechanism of graying. It's not uncommon to hear that stress causes gray hair. Researchers examining gray hair have found free radicals, or damaging chemicals caused by stress and environments, are responsible for destroying pigment. More testing will be needed to prove these connections.
Illness
Due to their being a strong association between age and illness, it's often asked whether or not gray hair is a sign of a shorter lifespan, or of illness. Studies suggest that it's more likely a part of the aging process and dictated by genetics, plus possible environmental factors. Keeping these points in mind, below are some conditions that have be found to cause gray hair, as cited by Harvard Medical School:
The science community is still working on the exact mechanism of graying. It's not uncommon to hear that stress causes gray hair. Researchers examining gray hair have found free radicals, or damaging chemicals caused by stress and environments, are responsible for destroying pigment. More testing will be needed to prove these connections.
Illness
Due to their being a strong association between age and illness, it's often asked whether or not gray hair is a sign of a shorter lifespan, or of illness. Studies suggest that it's more likely a part of the aging process and dictated by genetics, plus possible environmental factors. Keeping these points in mind, below are some conditions that have be found to cause gray hair, as cited by Harvard Medical School:
- Vitamin B12 deficiency
- Neurofibromatosis 1 (also called Von Recklinghausen’s disease)
- Tuberous sclerosis (an uncommon, inherited condition)
- Thyroid disease
- Vitiligo (this condition causes loss or destruction of melanocytes cells)
- Alopecia areata (a disorder in which patches of hair may be suddenly lost)
Can gray hair be "cured" (i.e. revitalizing the life and lifespan of melanocyte cells)?
Not yet, but the medical community is pretty optimistic that, at best, you can slow the aging process. Below are studies and articles highlighting the possibility of reversing gray hair.
Gray Hair can Return to its Original Color and Stress is Involved of Course
This article points out that some hair strands can have pigment near the scalp and a loss of pigment on the ends. This suggests that when the stressor was lower, melanin production started again.
Medication-Induced Repigmentation of Gray Hair: A Systematic Review
This study puts forth that some causes of prematurely graying hair are reversible. Nutritional deficiencies in Vitamin B12, iron, and copper, as well as severe protein malnutrition, have been linked to a diffusion of pigmentation.
Relationship between diet, atopy, family history, and premature hair graying
This study proposed a relationship between diet preference, having a normal weight, and decreasing alcohol consumption having an effect on slowing the graying process.
Topical RT1640 treatment effectively reverses gray hair and stem cell loss in a mouse model of radiation-induced canities
This study, done with mice, shows a pharmacological approach for reversing gray hair.
Relationships between Trace Elements and Premature Hair Graying
This study's goal was to monitor and document the relationship between premature graying and serum iron, copper, and calcium levels. Its findings are “premature graying may be an indicator that hair is not getting enough nutrients and minerals, and supplementation with these trace elements might reverse and is expected to prevent progression of canities; however, further studies are needed to find the underlying mechanism of this relationship.”
This article points out that some hair strands can have pigment near the scalp and a loss of pigment on the ends. This suggests that when the stressor was lower, melanin production started again.
Medication-Induced Repigmentation of Gray Hair: A Systematic Review
This study puts forth that some causes of prematurely graying hair are reversible. Nutritional deficiencies in Vitamin B12, iron, and copper, as well as severe protein malnutrition, have been linked to a diffusion of pigmentation.
Relationship between diet, atopy, family history, and premature hair graying
This study proposed a relationship between diet preference, having a normal weight, and decreasing alcohol consumption having an effect on slowing the graying process.
Topical RT1640 treatment effectively reverses gray hair and stem cell loss in a mouse model of radiation-induced canities
This study, done with mice, shows a pharmacological approach for reversing gray hair.
Relationships between Trace Elements and Premature Hair Graying
This study's goal was to monitor and document the relationship between premature graying and serum iron, copper, and calcium levels. Its findings are “premature graying may be an indicator that hair is not getting enough nutrients and minerals, and supplementation with these trace elements might reverse and is expected to prevent progression of canities; however, further studies are needed to find the underlying mechanism of this relationship.”
Sources
- The Aging Hair Pigmentary Unit
- Medication-Induced Repigmentation of Gray Hair: A Systematic Review
- Greying of the human hair: a worldwide survey, revisiting the '50' rule of thumb
- Premature Graying of Hair: Review with Updates
- Towards a “free radical theory of graying”: melanocyte apoptosis in the aging human hair follicle is an indicator of oxidative stress induced tissue damage