Itís Never Too Late for Sun
Dermatologists are frequently asked by their patients who have
actinic keratoses (AKs), ďDoctor, why do you want me to start
protecting my skin from the sun now? Hasnít the damage already been
While it is true that AKs develop on
skin that has significant sun damage, twenty-plus years of research
shows that sun protection can be beneficial after the skin is
damaged by unprotected exposure to ultraviolet (UV) light. These
studies indicate that sun protection may:
Since a person with AKs is always
considered at risk for developing new lesions and any single lesion
has the potential to progress to squamous cell carcinoma, a type of
skin cancer that can be deadly, the findings are certainly
encouraging. Studies indicate that sun protection may inhibit p53
gene mutations - mutations that contribute to the development of
skin cancer in humans and mice. Gene p53 acts as a tumor suppressor;
however, repeated UV exposure causes p53 to mutate - stifling its
tumor-suppressing abilities. These mutations begin long before skin
cancer develops because p53 mutations are found in AKs and
sun-damaged skin. In a scientifically controlled study, sun
protection reduced p53 mutations by 88% to 92%, implying that sun
protection may inhibit the development of skin cancer.
More compelling evidence for practicing
sun protection after signs of damage are visible comes from
dermatologic research that shows skin can repair some of the UV
damage when protected from further exposure. One study indicates
that damage to the dermis - middle layers of skin that contain
collagen and elastin - was partially repaired when protected, even
with continued UV exposure. Another study found that destruction and
repair occur simultaneously with continued UV exposure. However, the
more UV exposure received, the more destruction outpaces repair.
This study also found that when UV exposure ceases, both the outer
and middle layers of skin can repair some of the damage. Given this
finding, researchers concluded that while sun protection should
begin early in life, mature adults who have sun-damaged skin should
adopt protective measures.
Sun Protection: More than Occasional
Sunscreen use is only part of a comprehensive sun-protection
plan. In addition to daily application of a broad spectrum (protects
against both UVA and UVB rays) sunscreen that has a Sun Protection
Factor (SPF) of 30 or more, the American Academy of Dermatology
Avoid deliberate tanning.
Ultraviolet light from the sun and tanning beds causes skin cancer
and wrinkling. If you want to look like youíve been in the sun,
consider using a sunless self-tanning product. When using a
self-tanning product, you should continue to use sunscreen.
Get vitamin D safely through a
healthy diet that includes vitamin supplements.
Donít seek the
Generously apply sunscreen to all
exposed skin. Before going outdoors, generously apply a
sunscreen that has a Sun Protection Factor (SPF) of at least 30 and
is broad-spectrum ó protects against both ultraviolet (UVA) and
ultraviolet B (UVB) rays. While outdoors, re-apply the sunscreen
approximately every two hours, even on cloudy days, and after swimming or
Cover up when you must be in the
sun. Wear long sleeves, pants, a wide-brimmed hat, and
sunglasses that protect against both UVA and UVB rays.
Clothing protects your skin from the
sunís harmful rays. The tighter the
weave, the more sun protection provided. In fact, clothing plays
such an important role in sun protection that clothing designed
specifically to protect against the sun as well as laundry additives
created to boost clothingís protective function are available. Your
dermatologist may be able to provide you with more information about
A wide-brimmed hat shades your face and
neck from the sunís rays.
Wide-brimmed means the brim circles the entire hat and shades the
face and neck.
Use extra caution near water, snow,
and sand. These reflect the damaging rays of the sun, which can
increase your chance of sunburn.
The next time your dermatologist brings
up sun protection why not surprise your doctor by mentioning that
you know how important sun protection can be for a patient with AKs.
You may even want to ask for sunscreen recommendations as the
choices can be overwhelming.
Ananthaswamy HN et al. Inhibition of
UV-induced p53 mutations by sunscreens: implications for skin cancer
prevention. J Investig Dermatol Symp Proc. 1998
All content solely developed by the American Academy of
Some UV light gets through sunscreens.
American Academy of