Role of Melanocytes in Skin Color
Melanocytes are pigment-producing cells located in the epidermal layer of the skin. These cells are also found in the eyes, hair and intestines. Melanocyte cells are responsible for skin color and the degree to which it reacts to the sun. Everyone has roughly the same number of melanocytes. Skin color is determined by the amount of pigment, called melanin, that these cells produce.
People with darker skin tones have melanocytes that produce an increased amount of melanin, while those with lighter skin tones produce less melanin. Melanin production and skin color is influenced by genetics, although some diseases can affect the activity of melanocytes in the skin.
Link Between Melanin and Skin Cancer
Chronic skin exposure can lead to skin cancer. This is true even if you do not burn, according to the American Academy of Family Physicians. When the skin is exposed to the ultraviolet rays of the sun, the melanocytes in the skin increase production of the pigment melanin. Increased melanin production is what causes the browning of the skin known as a tan.
While all three primary types of skin cancer have been linked to sun exposure, the most dangerous type, melanoma, is directly linked to melanin. According to the American Cancer Society, melanoma develops in pigmented tissues of the body, mainly in moles or in the eyes. Darker skin has a greater natural protection against UV radiation from the sun, resulting in less cell damage and a decreased risk of developing melanoma and other skin cancers.
Reduced Skin Cancer Rates in Darker-Skinned People
According to the Centers for Disease Control and Prevention, skin color is responsible for the ethnic differences in observed skin cancer rates. While darker-skinned people do develop skin cancer on sun-exposed areas, the rates of skin cancer are significantly lower than those for lighter-skinned people.
The incidence of melanoma is 20 times higher in whites than in blacks, with Hispanics falling somewhere in between. The rates of squamous cell and basal cell carcinoma are as much as 80 times higher in whites than in blacks. Those with the least amount of pigmentation, such as those with very fair skin, and blonde or red hair, are at highest risk for all types of skin cancer. Skin color helps prevent skin cancer by naturally protecting skin cells from damage caused by the sun's UV (ultraviolet) radiation.
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