Proof
Positive
A study published in the Journal of Investigative Dermatology
(January 2003, pages 65–71) reaffirms the need for complete
UVA- and UVB-protecting ingredients when it comes to sunscreen
formulas. The study stated that ultraviolet radiation
(at wavelengths of 280–400 nanometers, which is the UVA
and UVB range of sunlight) inhibits the function of immune
cells known to fight skin cancer. "Sunscreens are
widely advocated to protect against skin cancer but if
they offer insufficient protection... they may inadvertently
increase skin cancer risk. This human study evaluated
[the immune protection provided] by a commercial sunscreen
preparation (labeled sun protection factor 15) offering
primarily ultraviolet B (280-320 nm) protection."
Note that to sufficiently protect against UVA rays, the
sunscreen must protect against rays that range in wavelength
up to 400 nanometers, which this sunscreen did not even
come close to covering. The sunscreen protected against
sunburn from the UVB rays, but hardly shielded the skin
against depletion of immune protection caused by UVA rays.
This study suggested that sunscreens should be formulated
to offer equally full protection from both UVB and UVA
rays. I concur wholeheartedly.
There is also growing research showing that topically
applied antioxidants can help protect from sun damage.
Although antioxidants don't replace the need to use sunscreens,
when used in combination with them, they are highly effective
and a wonderful addition to the protective value of a
well-formulated sunscreen (Source: Journal of Cosmetic
Science, November-December 2003, pages 589-598; Cosmetics
& Toiletries, August 2002, page 100; and Photodermatology,
Photoimmunology, and Photomedicine, April 2003, pages
56-72.). Vitamins (especially E and C) have been the topic
of several studies on the photoprotective effects of antioxidants
when combined with sunscreens. It appears that both vitamins
C and E have unique abilities to boost the effectiveness
of active sunscreen ingredients, with vitamin E proving
to be better at boosting UVB protection while vitamin
C demonstrated stronger protective effects against UVA
radiation. In tests on animal skin, the combination of
vitamins C and E with sunscreen proved to offer more protection
than sunscreen alone (Source: Journal of Investigative
Dermatology, August 2003, pages 406-411). Vitamin A (in
the form of retinyl palmitate) has also shown photoprotective
effects when used topically. A study on human skin showed
that topical application of retinyl palmitate (the amount
used was not revealed) was as effective at preventing
sun-induced redness as a sunscreen rated at SPF 20 (Source:
Journal of Investigative Dermatology, November 2003, pages
1163-1167).
Other antioxidants that have shown protective promise
for use in sunscreen formulations include selenium, resveratrol,
natural and synthetic astaxanthin, and canosic acid [a
component of rosemary] (Sources: Toxicology & Applied
Pharmacology, Volume 186, Issue 1, January 2003, pages
28–37; Archives of Biochemistry and Biophysics, Volume
412, Issue 1, April 2003, pages 90–94; Journal of Dermatological
Science, Volume 30, Issue 1, October 2002, pages 73–84;
and Free Radical Biology and Medicine, Volume 32, Issue
12, June 15, 2002, pages 1293–1303). Of course, other
antioxidants are being studied too.
Antioxidants also serve as topical anti-inflammatory
agents and that's a good thing, because keeping skin inflammation
to a minimum is critical to its healthy functioning and
outward appearance.
The bottom line is that shopping for sunscreens should
no longer be just about making sure the active ingredients
provide adequate broad-spectrum (meaning UVA and UVB)
protection. Rather, you should also shop for sunscreens
that contain sufficient amounts of antioxidants (if they're
listed after the fragrance or preservatives, don't bother,
that means there isn't enough in the product to benefit
skin). Such well-formulated sunscreens can be found at
the drugstore, department store, in my Paula's Choice
product
line, and at other online locations (if shopping online,
make sure the products you're considering list their complete
ingredients so you can make an informed decision).