A viewer recently asked... if 80% of your lifetime ultraviolet exposure and damage is done by the age of 18, then what’s the point of ongoing sun protection as an adult. Is it just a waste of time? What do you think?
It’s a fact that the only way you can develop premature wrinkling and other damage of your facial skin is by unprotected sun exposure. It’s also a fact that unprotected sun exposure is one of the main causes of skin cancer. And in an early DermTV episode three years ago, I mentioned that it was believed that 80-90% of your lifetime exposure to ultraviolet light occurs by the age of 18.
Based on that last statement, it’s very reasonable to ask what is the marginal benefit of a lifetime of effort of continuing sun protection if so much of the damage has already been done by age 18. Really... why bother with ongoing sun protection in your adult life?
Well, this is a very timely question because recent research reveals very different statistics than the ones I quoted and which, from a common sense point of view, just make more sense. The new research tells us that by age 18 you’ve actually only accumulated about 23% of your lifetime UV exposure and damage, and by age 40, 46%, which is another 23 %. From age 40 to 60, you get 27%, and from 60 to 78 another 27%... for a total of 100%. This study was based on a 78 year life span.
These results make much more sense and essentially say that in the first four twenty year periods of life you accumulate almost equal amounts of UV exposure and damage. And these results are much more consistent with both common sense and the ongoing, lifetime importance of ongoing protection from damaging ultraviolet rays, whether from the sun, tanning salons or any other source.
I’ve never told a patient not to go out in the sun, but I do tell them how to protect themselves when they’re in it… by applying and appropriately reapplying sunscreen with an SPF of 15 to 30 with UVA or broad spectrum protection. As long as the sun shines, use sunscreen!