When you get back from a sun-filled vacation, your friends may say you have a “healthy tan” – but contrary to popular belief, there is nothing healthy about a suntan. In fact, an acquired tan is really your skin’s cry for help. UV radiation is damaging to our skin cells. It causes structural changes to our DNA, which can lead to genetic mutations, and possibly skin cancer, if not repaired appropriately.¹⁻²
Melanin is a natural substance responsible for skin colour. Individuals with high amounts of melanin have darker skin compared to those with low amounts of melanin. It forms a protective, UV-absorbing shield around our skin cells’ DNA.¹⁻² Scientists believe that melanin provides a sun protection factor (SPF) of about 1.5-4. This is why individuals with darker skin are less vulnerable to the harmful effects of UV radiation, like sunburns and skin cancer.²
Tanning is a protective measure that your body takes when it senses danger from UV rays. When you expose your skin to UV radiation from the Sun, melanin is transferred from melanocytes (cells that make melanin) to keratinocytes (another type of skin cell). This causes your skin to tan.¹
Although a tan slightly reduces the risk of developing a sunburn, the Skin Cancer Foundation does not recommend intentionally acquiring a tan for this small benefit. Tanning is not worth the risks of UV-induced DNA damage or premature aging.³ It is important to wear SPF30+ sunscreen while outdoors, no matter your skin colour, to prevent the negative consequences of UV overexposure.
- Costin, G.E. and Hearing, V.J. (2007). Human skin pigmentation: Melanocytes modulate skin color in response to stress. FASEB J 21(4):976-994. Retrieved on June 7, 2016 from http://www.ncbi.nlm.nih.gov/pubmed/17242160.
- Brenner, M. and Hearing, V.J. (2008). The Protective Role of Melanin Against UV Damage in Human Skin. Photochemistry and Photobiology 84(3):539-549. Retrieved on June 7, 2016 from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671032/.
- Wang, S.Q. (2011). Is a Tan Ever a Good Thing? Retrieved on June 7, 2016 from http://www.skincancer.org/prevention/tanning/is-a-tan-ever-a-good-thing.