Q: Do self-tanners offer any sun protection if they don’t contain sunscreen?
A: Yes. Studies released in the late 1990s by researchers at the University of Nebraska Medical Center in Omaha indicate sunless tanning lotions that contain dihydroxyacetone (DHA) – the skin-darkening agent in most self-tanners – offer long-lasting protection from damaging UV light regardless of a person’s activities. Although the “tan” that’s produced rates about an SPF 4, the researchers say it offers day-long protection from some harmful UVA, UVB, and visible radiation and sticks around even after exposure to soap and water, mild rubbing, sweating, and swimming. The best part: wearing sunscreen over a fully developed bottled tan increases the protection value of the sunscreen, perhaps up to three times the stated SPF on the sunscreen bottle. According to researcher John A. Johnson, Ph.D., bottled tans are very valuable to young children or fair-skinned individuals who rarely tan but burn frequently. For the best protection, the Omaha group suggests reapplying the “tan” every three days.
Other research indicates the “tan” achieved when DHA stains the skin through a harmless process involving changes in surface cell proteins is similar to melanin’s broad-spectrum but low-grade UV protection. Like melanin, DHA seems to be especially effective at reducing exposure to UVA radiation—the sun’s primary aging ray that penetrates glass is constant year-round from sun up to sun down, from the equator to the poles, and is emitted in low doses by fluorescent and halogen lights. Researchers have also shown a strong link between UVA and the formation of malignant melanoma, the lethal form of skin cancer.
Also, like melanin, the darker the DHA-induced “tan,” the more UVA protection is provided. Speaking at the American Academy of Dermatology’s 2000 annual meeting in San Francisco, dermatologist Stanley B. Levy, MD, adjunct clinical professor of dermatology at the University of North Carolina School of Medicine, Chapel Hill, North Carolina, told dermatologists there’s “a dose-response relationship from the concentration of DHA used to color the skin—in this case from 2.5–6.5% of the formula—and the UVA protection factor it provided. The highest DHA concentration studied produced the darkest color change on the skin and the highest level of UVA protection.”
Yet another study found that concentrations of 15% DHA applied to the skin allowed higher doses of UVA to be tolerated by psoriasis patients undergoing Turbo-PUVA treatment, resulting in faster clearing of the psoriatic plaques and fewer overall treatments.
Even though the protective benefits for DHA have long been proven, it’s important to note the self-tanner doesn’t compare when up against the protection offered by true SPF sunscreens. Still, the harmless “tan” offered by DHA still is preferable to the damage done when melanin is developed via UV exposure. According to Levy, “Skin darkened through the sun or tanning beds actually is (a sign of DNA) damage by UV radiation in the process, and any UVA protection that may result from it does not make up for the fact that the damage already has occurred.”
Some words of caution: because the UV protection offered by a DHA “tan” takes several hours to develop, it does not meet the U.S. Food and Drug Administration’s (FDA) test standard required for determining SPF. So DHA alone is not approved as a sunscreen in the United States. If you are in a position to recommend a self-tanner, don’t make a sunscreen claim unless the product contains FDA-recognized sunscreens, too. And while some self-tanning products contain FDA-approved sunscreens, the protection they offer is only for a few hours—about the time it takes to develop the “tan”—not the duration of the “tan” itself.
Bottom line: The research suggests cumulative sun damage could be reduced if more people simply would apply self-tanning lotion to produce a dark “tan” every three days or so throughout the year. This usually requires 5–6.5% DHA levels in a formula or can be achieved with a couple of applications within a 24-hour period using lower-percentage DHA products. It is still wise to wear sunscreen daily for the most thorough protection. But, if researchers are right, when sunscreen is applied over a DHA “tan,” you should get greater SPF protection than indicated for the sunscreen alone.
