Melanin is a pigment naturally present in the human body, responsible for the colouring of the skin, hair and eyes. Melanin is produced from an amino acid, tyrosine, in specialised cells called melanocytes, located in the basal layer of the epidermis. There are two types of melanin: eumelanin, which gives a brown or black colour, and pheomelanin, which gives reddish (freckled) or yellow tones.
What is the purpose of this skin pigment? What are the benefits of this hormone?
The main function of melanin, which is not strictly speaking a hormone but an amino acid, is to protect the skin from potentially serious damage caused by the sun's ultraviolet (UV) rays. It helps combat free radicals. By absorbing and scattering UV rays, melanin prevents these harmful rays from causing sunburn and damaging the DNA of skin cells. It can also play a role in reducing skin ageing by reducing the damage caused by sun exposure, which can accelerate the appearance of wrinkles and the loss of skin elasticity.
Melanin and the sun: how does melanin protect the skin?
Exposure to the sun stimulates the production of melanin, a process known as tanning. When the skin is exposed to UV light, melanocytes increase production of the pigment to protect the skin from damage, resulting in darker skin colour. However, excessive exposure to the sun can exceed the capacity of melanin. The natural melanin present in the skin is not enough to protect the skin from UV damage, and sun protection and/or covering clothing are essential when exposed to the sun.
Melanin and cancer in white and dark skins
Melanin offers some protection against the development of skin cancer by absorbing UV rays and reducing DNA damage. However, insufficient levels of melanin coupled with unprotected sun exposure, particularly in fair-skinned people, can reduce this protection and increase the risk of melanoma and other forms of skin cancer. Black and dark skins, although less at risk, are also susceptible to skin cancer, particularly carcinoma.
Sun protection and regular skin checks by a dermatologist are therefore essential for all skin types.
Melanin and black skin
Black skin (like very dark skin) contains more eumelanin, which gives it better natural protection against the harmful effects of UV rays. This greater quantity of eumelanin reduces the risk of sunburn and certain types of skin cancer. However, no-one is completely safe from sun damage. Whatever your skin colour, adopt sun protection measures.
Read the article by Dr Aoun, dermatologist Sun cream and black skin









