Departments
Health Matters
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17 July 1998 |
Vol. II, No. 2 |
Health Matters
Protection from sun damage: tips on sunscreens
With so many different sunscreen products on the market, I am confused about what to buy. How can I tell which is the best product?
"Before you consider which sunscreen to purchase, keep in mind that the best way to prevent damage is not to be outside and exposed during midday, when sunlight is at its highest period of intensity," says Tania Phillips, M.D., associate professor of dermatology at Boston University School of Medicine and dermatologist at Boston Medical Center. "Children and adults with fair skin and hair and light-colored eyes are at the highest risk and need maximum protection from sunlight. While darker-skinned people, especially Africans and African-Americans, tend to suffer less from the sun's harmful effects, people of all ages and races are susceptible to skin damage."
Whenever you are outdoors during the day, protect yourself from the damaging ultraviolet (UV) rays of the sun by wearing sunscreen. Chemical sunscreens work by absorbing UV light, while physical sunscreens (also known as physical blockers) reflect UV light off the skin.
"Chemical sunscreens are invisible once applied -- unlike the physical blockers, which are relatively thick and opaque, making them cosmetically undesirable for many people," says Phillips. Chemical protectants often contain PABA and PABA-derivatives, salicylates and cinnamates, while physical blockers are composed of titanium dioxide, zinc oxide, and talc. In recent years, many companies have eliminated PABA and its derivatives from chemical sunscreens because it stings when applied and may cause the skin to break out in an allergic reaction. People are less likely to have allergic reactions to physical blockers, which are often advertised as being chemical-free.
All brands of sunscreen products should come with a sun protection factor (SPF) rating, which indicates a multiple of how much time you can spend in the sun before burning. For instance, if you burn in 30 minutes without protection, an SPF of 15 would allow you to spend 15 times longer in the sun before burning. Dermatologists recommend SPFs of at least 15 for all skin types and generally agree that SPFs of 15 to 18 provide maximum protection (higher SPFs are not believed to confer greater protection). Children especially should wear protective clothing and sunscreens at all times outside, and babies under six months should be kept out of the sun altogether. If you intend to swim, look for waterproof sunscreens made especially for bathing.
Phillips notes that while sunburns cause immediate pain and are the most obvious sign of skin damage, a more serious long-term problem is photoaging, in which the skin gradually becomes discolored, sallow, and wrinkled -- a process that is hastened by repeated tanning. Additionally, UV exposure increases the risk for the following skin cancers: basal cell carcinoma, squamous cell carcinoma, and melanoma, the most deadly of the three.
Be aware that quick-tanning lotions do not necessarily contain sunscreen. Most often, they contain dyes that color the skin, but do not stimulate production of melanin, the body chemical responsible for the color of a tan. These lotions (which may contain chemicals such as DHA) are not harmful to the skin, but likewise do not help protect the skin from the sun.
Keep in mind the following five points, and you should be well protected against skin damage from UV exposure:
- There is no such thing as a healthy tan.
- Avoid unnecessary sun exposure between 10 a.m. and 3 p.m.
- Wear protective clothing, a broad-brimmed hat, and UV-opaque sunglasses.
- Wear sunscreen with an SPF of 15 or higher when outside.
- A tanning salon produces the same skin damage as natural sunlight.
"Health Matters" is written in cooperation with staff members of Boston Medical Center. For more information on sunscreens or other health matters, call 638-6767.