Truths, Lies, and Sunscreens (cont.)
Am I protected enough if I am wearing a white T-shirt?
Long ago, I was really surprised to find out that a T-shirt gives you very little protection, equivalent only to about an SPF 7 or 8! That is hardly enough sun protection. Denim clothing provides an SPF 25-30. There are clothing manufacturers like Solumbra who make cooler, high-SPF fabrics.
Some people say using sunscreen may cause skin cancer. What do you think about this?
I have not seen any reliable, large-scale scientific data to suggest
this. On the contrary, everything we have seen points to excess sun as the cause
of premature skin aging, wrinkling, precancers, and skin cancers. Other factors
like genetics and heredity also play a role in determining who develops skin
cancer, but we really have no control over our genes. We can't choose different
genes or parents, so we ought to do something about what we do have control
I've read that sunblocks cause vitamin D deficiency.
It is hard to assess this possible association. It is true that recent evidence shows many people may be deficient in vitamin D. It is recommended that daily calcium and vitamin D supplementation along with a good multivitamin is a good idea for most of us.
What other sunscreen advice do you have for us this summer?
Choose a broad spectrum sunscreen that blocks both UVA and UVB rays. I still prefer zinc- or titanium containing ones; they are pure physical blockers. Reapply, reapply, reapply! Remember that the sunscreen that sweats off or is washed off is no longer there protecting you. It is best to reapply sunscreen frequently when outdoors for a long time. I like applying a quality zinc-based sunblock before leaving home and then applying a spray sunscreen as needed for touch-ups during the day.
What general skin care tips do you give your patients?
The sun is not your friend! Our main prevention measures are aimed at sun avoidance and sun protection. These include
2. using wide-brimmed hats (6 inches),
3. using physical barriers when possible like sun-protective clothing and sunglasses,
4. avoiding the peak sun hours of 10 a.m. to 4 p.m., and
5.seeking shade and staying indoors.
Here are some of the doctor's favorite sunscreen picks:
Last Editorial Review: 7/8/2008