Is Sunscreen Really Necessary for Your Children?
It's an annual rite of spring. You drag out the old sunscreen, toss out the old, expired bottles, and make a trip to the store for fresh batches of the stuff. After agonizing over which brands are best, you spend a small fortune on enough new sunscreen to protect the family for another year of outdoor fun and activities. Then you go home and the battle is rejoined: You insist that the children slather it on before going out. They resist, and you persist...It can get old pretty quickly. You think you're doing the right thing, but you're not entirely sure. Is all that wrangling over sunscreen really necessary? And what about infants? Is it safe to slather sunscreen on an infant? Is it necessary? You betcha. And here's why.
Sunscreens work by blocking or absorbing the skin-penetrating portion of sunlight known as ultraviolet (UV) radiation. UV comes in several wavelengths; UVA, UVB and UVC. UVA and UVB can both penetrate deep within skin tissues, and both have been linked to cellular damage that ultimately results in premature aging and an increased risk of skin cancer.
Yet despite widespread use of sunscreens, the incidence of malignant melanoma—the deadliest and most aggressive form of skin cancer—has continued to rise at an alarming rate. The American Cancer Society predicts there will be 75,000 new cases of melanoma this year, for example.
So, what gives? Some have speculated that our use of sunscreen has actually promoted this rise in melanoma cases, because we're spending more time in the sun, with little apparent effect, thanks to the use of sunscreens. Could all that extra time spent in the sun somehow be related to rising melanoma cases? Perhaps, but until now, no good animal models existed to help us understand the role of UV exposure in melanoma development.
Now researchers at the Texas Biomedical Research Institute have identified a suitable animal model of human melanoma. It's a small opossum from South America, and investigations involving young animals that were exposed to known amounts of UV radiation—with or without the benefit of sunscreen—have shown that sunscreen use in childhood really does protect against the development of melanoma later in life. Investigators used a common facial sunscreen lotion with SPF 15 for their study. It reduced the incidence of "pre-melanotic lesions" by 10-fold.
"Based on these results, we speculate that the reason it is particularly important that sunscreens be used consistently in childhood, and especially in infancy, is because skin cells during growth are dividing much more rapidly than in adulthood, and it is during cell division that the cells are most susceptible to UV-induced damage," said senior author John L. VandeBerg, Ph.D., in a press release. "Evidence that supports this hypothesis is that melanoma is not induced in adult opossums when their shaved skin is irradiated by UV light in the absence of sunscreen."
Texas Biomedical Research Institute. "Conclusive evidence that sunscreen use in childhood prevents development of malignant melanoma in adults." ScienceDaily. ScienceDaily, 19 June 2014.