By Tiffany Sosa
Skin color can be everything from very pale to very dark, and many shades in between.
Your skin color depends primarily on melanin (MEL-ah-nin), or pigment, which is made in the epidermis (ep-uh-DUR-mis). Your epidermis is the outermost and thinnest layer of your skin, and your skin is your body’s largest and fastest-growing organ.
The body produces two types of melanin: pheomelanin (fee-oh-MELuh-nin), which is red to yellow in color, and eumelanin (yoo-MEL-uh-nin), which is dark brown to black.
People with light-colored skin mostly produce pheomelanin, while those with dark-colored skin mostly produce eumelanin.
The more melanin your skin makes the darker your skin is.
How much melanin your body makes depends on your genes, which you get from your parents. Melanin is also a natural sunscreen that protects tropical peoples from the many harmful effects of ultraviolet (UV) rays.
Skin tone varies, with the darkest populations around the equator and the lightest ones near the poles. Put simply, a dark complexion is advantageous in sunnier places, whereas having fair skin fairs better in regions with less sun.
According to the National Museum of Natural History, “coastal peoples who eat diets rich in seafood enjoy this alternate source of vitamin D.” This means their skin can remain darker longer than inland skin tones.
Your melanin levels are the reason why you either tan or burn.
When you go out in the sun, your body makes more melanin. That’s because it’s trying to protect you from the sun’s damaging rays by deflecting or absorbing them. But melanin isn’t strong enough to completely protect you, especially if you have pale skin.
Melanin helps protect sensitive cells from the sun’s UV light, but it does not provide enough protection to prevent skin damage.
Daily use of a broad-spectrum sunscreen with a sun protection factor (SPF) of 15 or higher can help the melanin protect the skin from burning, skin cancer, and premature aging. Broad-spectrum means that the sunscreen product has been shown to protect against both UV-A and UV-B radiation from the sun.
If sun exposure is too high or protection too weak, despite our skin’s best efforts, sometimes the damage is irreversible. If a cell is very badly damaged, the cell activates a program called apoptosis, or programmed cell death. When cell death doesn’t occur, this leads to the risk of skin cancer.
Agbai ON, et al. Skin cancer and photoprotection in people of color: a review and recommendation for physicians and the public. J Am Acad Dermatol. 2014;70(4) 748–62
Milady. Milady Standard Cosmetology 2013. Milady.
Modern Human Diversity – Skin Color. (2018, September 14). Retrieved from http://humanorigins.si.edu/evidence/genetics/human-skin-color-variation/modern-human-diversity-skin-color