The best way to lower your risk of skin cancer is to protect your skin from the sun and ultraviolet (UV) light.
Using sunscreen and avoiding the sun help reduce the chance of many aging skin changes, including some skin cancers.
However, it is important not to rely too much on sunscreen alone. You should also not use sunscreen as a reason to increase the amount of time you spend in the sun. Sunscreens do appear to protect against melanoma, though the evidence they protect against other types of skin cancer is not as strong.
Even with the use of sunscreens, people should not stay out too long during peak sunlight hours. Even if you do not sunburn, UVA [ultraviolet A (long-wave)] rays can still penetrate your skin and do harm.
The best way to prevent skin damage is to avoid excessive sun exposure:
Avoid sun exposure, particularly during the hours of 10 a.m. to 4 p.m., when UV rays are the strongest.
The dangers are greater the closer to the start of summer.
Use sun protection, even on cloudy days. Clouds and haze do not protect you from the sun, and in some cases may intensify UVB [ultraviolet B (shortwave) rays.
Avoid surfaces that reflect light, such as water, sand, concrete, snow, and white-painted areas.
Skin burns faster at higher altitudes.
Avoid sun lamps, tanning beds, and tanning salons. The machines use mostly high-output UVA rays.
Wear protective clothing and a hat to shield your face from the sun's rays.
You can also buy sun protection factor (SPF) clothing and swimwear that block out UV rays. This clothing is rated using SPF (as used with sunscreen) or a system called the ultraviolet protection factor (UPF) index. The clothing is expensive, however.
Everyone, including children, should wear hats with wide brims.
Look for loose-fitting, unbleached, tightly woven fabrics. The tighter the weave, the more protective the garment.
Washing clothes over and over improves UPF. An easy way to assess protection is simply to hold the garment up to a window or lamp and see how much light comes through. The less light the better.
Everyone over age 1 should wear sunglasses that block all UVA and UVB rays when in the sun.
Use sunscreens that block out both UVA and UVB radiation. Look for products that contain either zinc oxide or titanium oxide.
Less expensive products that have the same ingredients work as well as expensive ones.
Older children and adults (even those with darker skin) benefit from using SPFs of 15 and over.
Some experts recommend that most people should use SPF 30 or higher on the face and 15 or higher on the body.
Adults who burn easily and anyone with risk factors for skin cancer should use SPF 50+.
When to use sunscreen:
Adults should wear sunscreen every day, even if they go outdoors for only a short time.
Apply 30 minutes before going outdoors for best results. This allows time for the sunscreen to be absorbed.
Remember to use sunscreen during the winter when snow and sun are both present.
Reapply at least every 2 hours while you are out in the sunlight.
Reapply after swimming or sweating. Waterproof formulas last for about 40 minutes in the water, whereas water-resistant formulas last half as long.
How to apply:
Apply a large amount to all exposed areas. Pay close attention to your face, nose, ears, and shoulders. Do not forget your feet.
Use half a teaspoon each for the head, neck, and each arm and a teaspoon each for the chest area, back, and each leg.
Use a lip balm with sunscreen.
Apply generous amounts of sunscreen with a SPF of at least 30. The higher the SPF, the greater the protection.
Choosing the best sunscreen:
Choose a waterproof or water-resistant formula, even if your activities don't include swimming.
Avoid products that combine sunscreen and insect repellant. They may not work as well. Also, sunscreen should be re-applied often, while insect repellant applied too often could be toxic.
Sun Protection and Children
Sunscreens are safe in most toddlers and children, but they should not be the first and only lines of defense.
All young children should be well-covered with clothing, sunglasses, and hats. Children should be kept out of the sun during peak sunlight periods.
Do not use sunscreens on babies younger than 6 months without consulting a doctor.
Green AC, Williams GM, Logan V, Strutton GM. Reduced melanoma after regular sunscreen use: randomized trial follow-up. J Clin Oncol. 2011;29(3):257-263.
Lautenschlager S, Wulf HC, Pittelkow MR. Photoprotection. The Lancet [early online publication]. May 3, 2007.
Hexsel CL, Bangert SD, Hebert AA, et al. Current sunscreen issues: 2007 Food and Drug Administration sunscreen labeling recommendations and combination sunscreen/insect repellant products. J Am Acad Dermatol. 2008;59:316-323.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.