Sunscreen shortage: Harvard expert says most people don't use enough
The best sun protection for your skin starts with a sunscreen with an SPF of 30 or higher. (Fotolia.com / July 11, 2012)
Choosing the right sun protection and applying it properly are not only the most important steps to protect yourself from the sun's harmful rays but also the most misunderstood, says Dr. Kenneth Arndt, a clinical professor of dermatology at Harvard Medical School.
"Some think that a quick application of a tanning cream is sufficient and will last all day, but it won't," Arndt says. "Between one fourth and one half of all people who apply sunscreens use inadequate amounts, which obviously limits the sunscreen's effectiveness. For example, if an SPF 16 sunscreen is put on too thin, it's actually equal to an SPF 2, or an SPF 80 would become an SPF 3."
Dr. Arndt adds that the effectiveness of sunscreens diminishes within a few hours, and that cloudy and overcast days aren't as safe as you might think.
"Actually 70 percent to 80 percent of ultraviolet radiation gets through clouds and will cause photo damage," Arndt explains.
The best sun protection for your skin starts with a sunscreen with an SPF of 30 or higher. About one ounce, approximately two tablespoons, is needed for the average adult body. Dr. Arndt explains that about one quarter to one third of a tablespoon is right for the face.
Sunscreen should be applied to dry skin about 15 minutes before going out in the sun and should be reapplied every couple of hours.
Other protective measures include the use of wide-brimmed hats, as well as loose-fitting long sleeves and long pants.
"Sun is most intense between 10 a.m. and 4 p.m., so going out in early morning or late afternoon is best," says Dr. Arndt. "Stay in the shade. Watch out for reflection from water, sand, and snow (in the winter)."
He also notes that, despite popular belief, there is no such thing as a "healthy tan," because every tan is a response to skin damage.
KNOW THE RISKS
The effects of sun damage can be cosmetic: premature wrinkling, age spots, dryness, and a leathery complexion. But sun damage also can cause a variety of skin cancers.
These include increasing your risk of developing the non-melanoma skin cancers, basal and squamous cell carcinoma, which are caused by excessive sun exposure in 90 percent of instances, and the most serious, melanoma.
But knowing how to help avoid all that is no summer mystery.
"A recent prospective study," Dr. Arndt explains, "showed that regular sunscreen use significantly reduced the incidence of invasive melanomas."
It's not always that a practice as simple as properly using sunscreen can prevent a potentially fatal illness.--Harvard Health Letter