Why Are People With Red Hair More Prone To Skin Cancer?

Natural red hair is said to be the rarest of all hair colors. According to Rarest, approximately 1% to 2% of the global population has natural red hair, compared to the 75% to 85% who were born with natural black or dark brown hair. Northern and Western Europe, particularly the British Isles of Ireland and Scotland, are the most common places where people with naturally red hair can be found. Natural red hair is a recessive genetic trait, meaning that both parents must carry the gene in order for it to be passed on to their children. As explained by Eupedia, mutations in the melanocortin 1 receptor (MC1R) gene are responsible for someone having red hair. 

Someone can also carry genetic mutations for red hair without actually having red hair. Let's Talk Science explains that someone who has an allele for a recessive trait but doesn't express it is considered to be a carrier of that gene. Interestingly enough, two parents who have brown hair can still have a child with red hair if both of them carry the recessive allele for the MC1R gene.

The MC1R gene is not only involved in the shade of someone's hair, but it also plays a part in the pigmentation of the skin, reports Medline Plus. For example, redheads are known to be more likely to have freckles. Redheads have also been reported to be at increased risk of developing skin cancer, but why is this the case?

A person who has expressed the mutated melanocortin 1 receptor (MC1R) gene can have beautiful red locks that those with other hair colors might envy, but they are also more vulnerable to skin cancer. According to the Skin Cancer Foundation, redheads are more than one and a half times more likely to develop basal cell carcinomas. Additionally, their risk for developing squamous cell carcinomas is 12 times higher, and they have a genetic risk for melanoma. 

Some researchers suggest that having the genes associated with red hair, fair skin, and freckles may increase skin cancer risk at an equivalence to 21 additional years of sun exposure (per Reuters). A major reason for the increased risk of skin cancer for redheads is that the MC1R gene promotes a unique response to melanin, which is a pigment that serves to protect the skin against the sun's UV rays, according to APDerm. The pale skin of redheads doesn't tan when exposed to the sun because of a type of melanin called "pheomelanin," and is, therefore, more susceptible to sunburn.

Further research has discovered that individuals who have a defective MC1R gene may carry mutations that cause cancer that is unrelated to sun exposure, as reported by Medical News Today. In addition, those with just one allele of the MC1R gene may also be at an increased risk of skin cancer, which may be harder to detect if they don't have red hair or pale skin.