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The Truth Behind High SPF Sunscreens: Is More SPF Better?

Both Coppertone and Neutrogena have recently unveiled sunscreens with sun protection factors (SPF) of 70 and 85, respectively. In a spree of one-upsmanship, Banana Boat countered with its most potent SPF yet. Today, Neutrogena even offers sunscreens with sun protection factors in triple digits; these bigger-is-better strategies have left dermatologists scratching their heads.

The Science Behind Sun Protection Factor

According to Dr. Gilchrest from the Boston University School of Medicine, higher sun protection factors only bolster the fight against skin damage and photoaging to a point. In layman’s terms, the sun protection factor gauges how well a sunscreen protects against harmful, short-wave UV-B radiation. The UV-B radiation emanating from the sun is ultimately what causes sunburn.

The sun protection factor basically tells consumers how long they can bask in the sun without suffering visible UV-B damage and sunburn. Research shows that high SPF sunblocks may help prevent deep burns, but the higher SPF creams do not offer superior protection against penetrating UV-A radiation and aging damage.

The redundancy of high-SPF sunscreens is not missed on the Food and Drug Administration, who suggested a limit of 50 SPF in 2007. Unfortunately, companies like Coppertone are capitalizing on the credulity of consumers who assume higher SPFs must be superior. According to leading dermatologists, even SPF 100 does not offer 100 percent protection against sunburn, melanoma or skin damage.

High SPF Sunscreen

Types of UV Radiation and SPF Protection

Aside from the fact that both UV-A and UV-B radiation can cause skin cancer, consumers scramble for higher SPF ratings largely based on misconceptions. The UV-B blocking power between SPF 50 and SPF 100 creams is very minimal. The truth is that this 50 point disparity in SPF rating only spells an increase of one percent in UV-B blocking power; an SPF 50 blocks 98% of harmful rays whereas an SPF 100 blocks 99% of the same cancer-inducing radiation.

The sun protection factor is actually calculated based on the difference in times it takes an average person to burn unprotected versus protected with sunscreen. The idea is that if a person normally burns after only 30 minutes of sun exposure, s/he will remain protected 15 times longer with SPF 15. Some sunscreens, though, fall off when exposed to sweat or water, so reapplication is advised.

Other factors, aside from the SPF, can affect one’s propensity to burn; these factors include: the skin type of the sunscreen user, time of day at which exposure occurs, absorption of sunscreen, types of activities engaged in, and frequency of reapplication of sunscreen. Moreover, the SPF is a dubious measure of protection from harmful rays because invisible damage and photoaging is exacerbated by UV-A radiation; UV-A damage does not cause short-term reddening or discomfort.

The Jury is In Among Dermatologists

Dermatologists stress the importance of frequent reapplication rather than locating the highest SPF known to mankind. Considering the negligible difference between SPF 50 and SPF 100 in preventing UV-B damage, the advice of dermatologists is steeped in sound science.

While frequent reapplication is crucial, especially when swimming or excessively perspiring, using enough sunscreen is also an essential barrier against harmful rays. According to the senior director of scientific affairs at Johnson & Johnson, Dr. Appa, using half the recommended amount results in half of the promised protection against short-wave radiation.

That said, even sunscreens with high SPF ratings are dubious at protecting against the UV-A radiation that causes DNA damage and malignant melanomas. Nonetheless, high SPF sunscreens offer slightly more protection against UV-B radiation and sunburn. The sun protection factor, though, mainly indicates the time it takes someone to burn sunscreen-protected versus unprotected.