United States

The Doctors Weigh In: The Truth About SPF & Sun Exposure

5/12/2012 11:03:45 AM

We've all had those lazy moments where we've waited a bit too long to put on some SPF products (but I wanted to first take a quick dip in the water...), dug a bottle of sunscreen out of the cabinet from last year, or completely forgot to bring the sunhat along. Furthermore, we may have wanted to just "get some color," or a "base tan," before a trip, or feel that our makeup, which has SPF, is adequate coverage for the day. Realistically speaking, are we way off base here? Are we seriously damaging our skin for the future?

We spoke with four experts, renowned dermatologists and skin specialists Dr. Howard Murad, Dr. Andrew Jacono, Dr. David Colbert, and Dr. Vermen Verallo-Rowell to find out the truth about SPF; what rating is best, ingredients to look for, how to protect the head and scalp, the benefits of SPF in clothing, and more. Read on for our exclusive Q&A as the doctors weigh in with responses that will surprise, educate, and motivate you to form new healthy habits when it comes to sun care and skin protection (it did for us!). We showcased some of their responses together, and for the most part the wisdom and tips that our experts dolled out were in the same vein, but regardless of some slight difference in opinion, these professionals have imparted all around sound advice, so take heed!

What is the biggest myth about sunscreen?

Dr. Jacono: The biggest myth about sunscreen is that you do not have to reapply "waterproof" sunscreen. The truth is, sunscreen is water-resistant and not "waterproof." Sunscreen should be reapplied every two hours or after every swim. For the best results, you should put at least an ounce of sunscreen on 20 minutes before you go out in sun to give it time to absorb into your skin.

Dr. Verallo-Rowell: That people who are tanned/ or who tan easily/ or have generally darker skin color are protected by their tan/color, and therefore no longer need to apply a sunscreen. This is WRONG. A tan or medium dark skin color has a low SPF of 3 to 5 while only very dark skin can possibly give an SPF protection of 13-15. Even then, it's best to stay protected because while less darker-skinned people get skin cancer, they do get skin cancer and it's often diagnosed late, possibly because it's not top-of-mind and early warning signs may be dismissed. A sunscreen with high, broad-spectrum protection is needed for any skin tone-not just from UVB but also UVA, and now ideally also from Infrared, and Visible Light.

Is it a necessity to throw away products with SPF in them after each summer season, or do you think they can still be relatively effective after a year?

Dr. Colbert: Always throw away all of your old sunscreen. The molecules break down over time and lose efficacy.

Dr. Verallo-Rowell: Sunscreens are classified as over the counter drugs and must be treated as such, especially because they are often exposed to extreme conditions: kept in beach bags, or in car seats, on the sand, kept uncovered, with water contaminating it, etc. These conditions can make the emulsion break down and as sunscreen actives are notoriously unstable, the more exposure to extreme conditions, the higher the risk for instability (the product separates or the actives no longer protect that the tested factors).

The average shelf life of sunscreen is usually 1.5 years. But again, treat it like a drug: look at expiration dates, store it properly as much as possible, and examine it for signs of separation and other physical changes. Besides breakdown of the emulsion, sunscreen ingredients are photosensitive and need other sunscreen ingredients to stabilize them. Too much heat and sun exposure may break down the individual sunscreen actives, to destroy their sunscreening ability on the skin, as well as their photostabilizing effect on other sunscreen actives.

Dr. Jacono: Sunscreen may remain stable for up to 3 years, but it is best to replace it every year, to ensure that SPF is working at full strength.

Dr. Murad: If the product does not contain an expiration date, standard practice is to assume the product has a three-year shelf life so there is no need to throw out a sunscreen you purchased the summer before. But with proper application, a sunscreen should not last you that long! For each sunscreen application, apply one ounce of sunscreen (equal to a shot glass) to the entire body and face daily and continuously reapply when out in the sun for long periods of time. If you plan on swimming or being in water, apply water resistant sunscreen every 40 to 80 minutes for optimal protection.

Everyone seems to think that it is a good idea to get a 'base tan' before the summer or a vacation; does this really come into play with how much a person may tan, or burn?

Dr. Murad: The idea that a "base tan" will protect you from sunburn is false. All tanning is damaging. That's why sunscreens should be applied daily and continuously throughout the day - both indoors and outside to keep your skin well-protected.

Find more answers about sun exposure and SPF.

Continue Reading on stylecaster.com >