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Sunscreen Prevents Precancerous Spots

Daily Sunscreen Use Fights Early Signs of Skin Cancer

How to Make Sunscreen a Daily Habit continued...

"I think people are often deceived by hazy or cloudy days, but you are still getting UV [ultraviolet] exposure at that time," says Kauvar, who is clinical associate professor of dermatology at New York University School of Medicine. "At the beach, people who wait 20-30 minutes before putting sunscreen on are already behind the eight ball."

Kauvar says it takes about a half-hour for sunscreen to be absorbed completely into the skin and offer the best protection from the sun's damaging UVA and UVB rays. UVB rays are five to 10 times more damaging during peak sun hours between 10 a.m. and 2 p.m., but UVA rays are constant throughout the day and can pass through glass, like a car or office window.

That's why she says it's important to apply a broad-spectrum sunscreen with an SPF of at least 15 every day. But if you're going to be swimming, sweating, or participating in sports and unlikely to reapply sunscreen regularly, a higher SPF factor can provide more protection.

The SPF of a sunscreen tells you how many times your natural protection the product offers, which means you could be in the sun 15 times longer with a SPF 15 sunscreen than you could without any protection.

Kauvar offers these helpful hints when selecting and applying sunscreen:


  • Foundations, face powders, or other types of makeup that contain sunscreen aren't likely to offer as much SPF protection as indicated on the label because they aren't applied thickly enough. You are more likely to get better protection by using a separate product like a moisturizer containing a high SPF.
  • Men are more likely to develop sun-related skin cancers on their scalp, back of the neck, and the tops of their ears because they neglect to apply sunscreen in these areas when working or playing outdoors. Sunscreen sprays and sticks can be helpful in reaching these often forgotten areas.
  • Both men and women are most likely to get sun-related skin cancers on their nose because it gets the most sun exposure, which makes it a prime target for sunscreen.
  • If you experience skin irritation from using sunscreen, try one of the newer, chemical-free sunscreens containing zinc oxide or titanium dioxide. These new formulations reflect the sun's damaging rays but don't react with the skin. They can also safely be used around the eye without causing stinging if the product gets into the eye after sweating or swimming.

In an editorial that accompanies the study, John L. M. Hawk, MD, of St. Thomas' Hospital in London, UK, says the results demonstrate once again the great value of sunscreen application, "when undertaken conscientiously and carefully, against the now extremely well documented ravages of sunlight in both the short and long term."

In addition, the study also looked at whether daily beta-carotene supplements offered any protection in preventing skin cancer. Previous studies in animals have shown that this nutritional supplement reduced skin cancer in animals, but no protective effect in humans was found in this study.


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