By Kaelie Rivers Breiter
Red, carrot top, ginger. These were a few names I was called growing up because of my vibrant red hair. I did not particularly like my lighter auburn hair in my younger years, with its hints of blond and copper, as none of my friends had hair like mine. As I got older, though, I started to appreciate the uniqueness and color of it as I’d constantly get comments like, “I wish I had that color, I love that color! I’m constantly telling my hairdresser to make that color!” And now I truly appreciate my red hair as I have no gray hairs unlike most of my friends. What makes red hair? Why don’t redheads gray as quickly as other hair colors? Are we going extinct? I have been intrigued by these questions for a while, as my two daughters have also been blessed with beautiful red hair and my mother at the age of 77 has only splashes of silvery white throughout her dark red curls, making her look years younger.
Redheads come in many different hues, from bright flaming red to dark-red auburn to strawberry blond. In my investigation, it is estimated that only 1-2% of the population has natural red hair, so for every 100 people in the world, only one or two will have red hair. Strawberry blond hair is the rarest color, with it only occurring in .5% of the population. To make that percentage even lower, redheads with blue eyes make up only .17% of the population; both red hair and blue eyes are recessive. So 13 million people out of 7.6 billion on earth have this rare physical trait combination of red hair and blue eyes. Then what causes red hair?
Melanocytes are melanin-forming cells in your skin and hair. The amount and type of melanin your body produces determines how dark or light your skin and hair will be. Red hair is the result of a genetic variant that causes the body’s skin cells and hair cells to produce more of one particular type of melanin and less of another. Natural red hair is caused by a slight mutation on the MC1R gene on chromosome 16. There is some research that suggests chromosome 4 is also possibly involved for the red color. The MC1R also causes pale skin and freckles, which is usually associated with red heads. It is a recessive gene in our DNA, meaning red hair only occurs when both parents carry the gene. I found in my research that 40% of the population carries the mutated MC1R gene. So if both parents carry the gene (neither one has red hair) you have a 25% chance of having a redhead. If one parent is a red head and the other secretly carries the gene, you have a 50% chance of having a redheaded child, which occurred in my family. And if two redheads have children they have a 100% chance of having red haired children.
Redheads have different shades of red due to two pigments called eumelanin and pheomelanin. All hair colors are made up of these two pigment combinations. Usually the redder the hair, the more pheomelanin it contains and the darker the hair, the more eumelanin in it. The red pigment pheomelanin is present in our lips and nipples while the eumelanin pigment causes brown skin, hair, and tanning of the skin. As you get older, the amount of eumelanin and pheomelanin changes in your hair. So fading does happen, for example, a bright red head might become more blond because the hair follicle is producing less pheomelanin. And hair gains its natural color at the hair follicle. The particular mix of pigments that goes into your hair is a function of your genetics. So why do redheads gray slower? When people start getting gray or white hair, the hair follicle actually stops producing pigment. Once this happens all the hairs become white in a condition called achromotrichia, the absence of pigment in the hair. Redheads retain their natural pigment a lot longer than other shades. Natural red hair fades with age through a spectrum of beautiful blurred colors of copper to rosy-blonde, then to silvery-white. An interesting fact I found in my research is that red heads actually have less hair follicles than other hair colors. On average they have 90,000 strands compared to blondes with 110,000 strands and brunettes with 140,000 strands. But each red strand is thicker so it appears as though they have more hair in general.
So are my two red headed daughters, my mom, and I going extinct? No. A very common misconception is because a trait is rare it will be diluted and lost. Red hair is unlikely to suffer from this effect even though it is recessive, since we can’t always see red hair, but many people still carry the gene. Further evidence in my investigation revealed significant percentages of people carrying the gene for red hair in different parts of the world including Scotland, with an overall rate of 36.5%, Ireland with 34.7%, Wales with 38%, and England with 34.4% potential for having red haired children. Yes, red hair is rare and it is a recessive trait, but unless everyone that carries the gene stops reproducing, red hair will always exist.
An interesting fact is that redheads need 30% more anesthesia than other hair colors because they are harder to sedate and appear to be more sensitive to pain. In conclusion, red hair is a recessive trait that is only passed on if both parents carry the gene. It is caused by a mutation in the MC1R gene on chromosome 16, and redheads have more pheomelanin in their hair follicles, so ultimately our pigment takes longer to gray than other hair colors. And to conclude, we are not going extinct.
Questions:
What causes red hair?
Natural red hair is caused by a slight mutation on the MC1R gene on chromosome 16. The MC1R also causes pale skin and freckles, which usually goes along with red heads. It is a recessive gene in our DNA, meaning red hair only occurs when both parents carry the gene.
What is pheomelanin & eumelanin? Which pigment do redheads have more of?
The red pigment pheomelanin is present in our lips and nipples, and the eumelanin pigment causes brown skin, hair, and tanning of the skin. Redheads have more pheomelanin, so they do not gray as quickly as other hair colors.
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