Although the sun has not been shining lately in NYC, it is skin cancer prevention and detection month. Skin cancer is the most common of all cancer types. More than 1 million skin cancers are diagnosed each year in the United States. That’s more than cancers of the prostate, breast, lung, colon, uterus, ovaries, and pancreas combined.

The good news is that you can do a lot to protect yourself and your family from skin cancer. Most skin cancers are caused by too much exposure to ultraviolet (UV) rays. There are two types of rays to be concerned with, UVB and UVA. UVB rays cause a much greater risk of skin cancer than UVA. However, UVA rays cause aging, wrinkling, and loss of elasticity. UVA also increases the damaging effects of UVB, including skin cancer and cataracts. Much of this exposure comes from the sun, but some may come from man-made sources, such as indoor tanning lamps.

What’s important is understanding how to pick the right sunscreen. SPF is the universal measurement of UVB protection. SPF (sun protection factor): measures the length of time a product protects against skin reddening from UVB, compared to how long the skin takes to redden without protection. If it takes 20 minutes without protection to begin reddening, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer — about 5 hours. (Actually, it may take up to 24 hours after sun exposure for redness to become visible.) To maintain the SPF, reapply sunscreen every two hours and right after swimming.

The Skin Cancer Foundation recommends SPF’s of at least 15, which block 93 percent of UVB. While SPF’s higher than 30 block only 4 percent more UVB, they may be advisable for sun-sensitive individuals, skin cancer patients, and people at high risk of developing skin cancer. They also allow some margin for error if too little sunscreen is applied.

Our suntan lotions are good at screening out the sun’s UVB rays — the ones that cause sunburn and skin cancers — but most people don’t realize their sunscreens don’t offer much protection against UVA rays.

One product in particular that has both UVB and UVA protection is La Roche-Posay Anthelios XL Lait SPF. The reason is that is contains Mexoryl. Mexoryl MEXORYL™ SX is the most effective FDA-approved organic filter designed to protect against short UVA rays (maximum absorption at 344nm) with high photostability, a key factor in sunscreen protection efficacy. This high photostability means the sunscreen will maintain a higher UVA protective ability longer and not degrade as quickly as other FDA approved UVA filters when exposed to the sun. People are happily protecting themselves with Mexoryl on the beaches of Rio de Janeiro, the streets of Paris, in Canada, Mexico and Australia. It has just recently been approved by the FDA for use in the US.

The safety and efficacy data for Anthelios SX included information from 28 studies in over 2500 patients, ranging in age from 6 months to over 65 years old. In addition, the contribution of each of the active ingredients to sun protection was studied. Side effects reported during clinical studies were infrequent and non-serious. The most common side effects in patients were acne, dermatitis, dry skin, eczema, abnormal redness, itching, skin discomfort and sunburn.