sunscreen and melanoma
Conflicting news over sunscreen has left both sun-bathing enthusiasts and their indoor-loving counterparts in a tizzy. In case you haven’t heard the debate, we felt it wise to discuss the alleged risks and/or benefits of sunscreen smack dab in the middle of Melanoma/Skin Cancer Detection and Prevention Month.

The Environmental Working Group claims that in an investigation of nearly 1,000 sunscreen products, four out of five offer inadequate protection from the sun. 
The problem? Most sunscreen products claim they fight UV rays, but more often than not they protect against only the UVB rays, which result in sunburn, and not in fending off UVA rays, the rays responsible for aging and cancer.

A new set of FDA guidelines, which has been in the works for a decade, would help clear up misleading claims. The proposed set of guidelines would include a four star rating system for UVA protection that would be based on both in vitro and in vivo tests. They would incorporate a measurement of photostability, would be required to include the four-star rating on their sunscreen labels, and prohibit claims such as "chemical-free", "waterproof", or "helps prevent skin damage". Also on the list: SPF would no longer stand for "Sun Protection Factor", but would be "Sunburn Protection Factor" to distinguish its use as a measure of only UVB rays. And SPF designations would be capped at 50. The changes, according to the FDA, should be introduced in October of this year.

Even those that shy away from the sun should be cautious. Research from the FDA's Center for Devices and Radiological Health showed that although indoor workers typically receive 3 to 9 times less UV exposure than those outdoors, only the indoor group had an increased incidence of malignant skin cancer. The scientists think this could be because the UVA light penetrating through building windows would lead to mutations and a breakdown in Vitamin D3, which would otherwise help protect the skin against melanoma.

Amidst claims that sunscreen is not quite effective, some say it could even attribute to an increased risk of cancer. A study in the journal of Free Radical Biology and Medicine raised concerns about the effect of sunscreen when absorbed into the skin after reacting with the sun. The report suggests that under certain conditions, sunscreens with oxybenzone and other ultraviolet filters could lead to free-radical damage to the skin, a process that could theoretically lead to skin cancer. However, a study from 2003 with partial grant support from the National Cancer Institute concluded that there was no association between melanoma and sunscreen use.

Safety involving the absorption of nanoparticles have been investigated in Australia, which has the highest rate of skin cancer in the world. The Aussie government's Department of Health and Aging conducted a review in 2009 that found that to date there is no evidence that suggests that titanium dioxide and zinc oxide can reach viable skin cells. Instead, they remain on the surface of the skin, and in the outer layer of the skin that is composed of non-viable cells. Therefore, there should be no adverse effects.

Those that do like the outdoors may feel a false sense of security because of their sunscreen use. A study in the International Journal of Cancer suggests that sunscreens do not protect against melanoma, probably because of their ability to delay or avoid sunburn episodes, which may allow prolonged exposure to unfiltered ultraviolet radiation. Sunscreen users may be out in the sun longer, and use sunscreen lotions inconsistently. It is also a bit of a paradox. According to the Journal of Investigative Dermatology, sunscreen may also interfere with cutaneous vitamin D synthesis, which some say helps lower melanoma risk.

The Mayo Clinic argues that though sunscreens fail to filter out all harmful UV radiation, especially the radiation that can lead to melanoma, they do play a major role in an overall sun protection program. They suggest using sunscreens containing titanium dioxide and mexoryl, which do a better job at blocking UVA rays. Also in their list of tips: avoiding the sun at it's strongest, wearing protective clothing, and checking your skin regularly for any noticeable changes or marks.

Still confused on if you should or shouldn't be using sunscreen? Frankly, so are we. Though the claims that it could do you harm are alarming, we suggest finding the right sunscreens that block out dangerous UVA, and abiding by the American Cancer Society's mantra of "Slip, Slop and Slap." So slip on a shirt, slop on sunscreen, slap on a hat, and enjoy your sunny day!