Six Sun Tips

For most of us sun exposure comes to the forefront of our minds this time of year when we are getting outdoors for yardwork or vacations, but really we are exposed every day to the sun's radiation. Around 95% of solar radiation is UVA (the kind of radiation thought to cause more photoaging than skin cancer), but UVB causes more direct damage and is thought to be more important for causing things like skin cancer. With that background, here are some practical tips for sun care:

1. Wear a sunscreen of SPF 50 or more every day on your face and arms. I can think of virtually no exceptions to this rule. Even when you do not get a sunburn you are accumulating sun damage constantly. There are really two reasons to put on a very high SPF sunscreen. The SPF of your sunscreen declines over time. If you are not swimming, sweating or wiping your skin, then after 4 hours the number is reduced by a third. After 8 hours it is cut by two thirds, so if you start off with an SPF of 100 then on the ride home from work 8 hours later than you may still have in effect an SPF of 30 on your face.

2. Buy something that says "non-comedogenic" for the face. There are many nice brands of sunscreen out there. Most of the ones I like for the face say "non-comedogenic" somewhere on the label. This means it is less likely block pores on your face.

3. Sunscreen should not give you an excuse to stay in the sun for hours on end. Sunscreen has been shown to reduce the risk of melanoma (in 2011 for the first time), but that was in people who were getting "incidental" exposure. There is no proof that sunscreen alone can reduce the risk of skin cancers including melanoma in people who are getting more than "incidental" exposure. Sun avoidance with shade, hats, long sleeves, and going out early in the morning or in the evening instead of in the middle of the day are an essential part of sun health.

4. Clothes often have a lousy SPF. You might think that going outside with a T-shirt on protects that area from the sun's damaging rays. In fact, a regular cotton T-shirt gives you an SPF of only 10. I would never tell anybody to wear an SPF of 10 for any reason. It does not block enough radiation.

5. Put the sunscreen on and then wait before you get dressed or get in the water. Good studies have shown that people who either get dressed or get in the water right after they put on their sunscreen lose a lot of the SPF. If you can wait 20 minutes to let the sunscreen adhere well to your skin you will get the full benefit. This is yet another reason to use a very high SPF (as if you needed any more).

6. What about Vitamin D? This is a question I get a lot. The truth is that nobody knows how much Vitamin D is enough. Very smart people who study this full time argue about what the right dose of Vitamin D is. Right now the recommendation for most people is 600 Units a day. My best guess is that it will end up being higher like around 2000 Units per day because every time Vitamin D is studied it seems like more is better, and the toxicity from too much Vitamin D is actually very rare. It has never been seen in doses below 10000 Units per day.

As far as what brand of sunscreen is the best, there are many that are very similar. The important things are you want something "non-comedogenic" for the face and something with a very high SPF. I often tell patients to try several types and see which ones they enjoy the most. Neutrogena is widely available, comes in an SPF 100, and feels nice and dry after you rub it in. For the arms and chest you can try the Target brand spray (up & up) SPF 60, which did exceptionally well in the Consumer Reports sunscreen testing.

Enjoy all your summer activities and don't be shy about asking questions!