The number one most common form of cancer in the United States is skin
cancer. Over 5 million cases of skin cancer get diagnosed annually. According
to the American Cancer Society, that number is more than breast, prostate,
colon and lung cancer cases
combined. But what about all the negative press on sunscreen? There is a lot of
inaccurate information out there on sunscreen safety. Let’s discuss
An expert in the field, Elizabeth Buzney, MD, outpatient clinical director of the Department of Dermatology at Brigham
and Women’s Hospital, assistant professor of dermatology at Harvard
Medical School, and member of the Skin Cancer Foundation’s Photobiology
Committee, says, “For starters, we know that the sun causes most
skin cancers. That is absolutely proven.” While sunscreen has alleged
risks, the fact is they help protect your skin from the deadly risks of the sun.
To address the concerns regarding certain ingredients in sunscreen, oxybenzone
in particular, Buzney says, “One study showed uterine growth in rats. But if you look at that study, they
fed the rats a
huge amount of this chemical over the course of four days. To duplicate that
amount in humans would take applying sunscreen all over the entire body
every day for 70 years. It was not an accurate model for what a human
would be exposed to.”
There are a number of additional claims floating around that has not be
substantiated by hard science or evidence. One example is sunscreen that
contains vitamin A, or retinyl palmitate, causes skin cancer, however,
there is yet be a credible study to support that claim. The reality is
that sunscreen has not been proven to cause skin cancer, but it has been
proven to prevent it.
How should you use it?
Deborah Sarnoff, MD, senior vice president of the Skin Cancer Foundation
recommends a comprehensive program that should be followed daily—not
just when you're at the pool or the beach. Her program also urges
thinking beyond sunscreen. Include hats, sunglasses, and seek shade when
possible. She also encourages avoiding peak hours in the sun.
What sunscreens should you use?
All sunscreens are not all created equal. They are typically labeled with
an SPF, or sun protection factor, number which represents a relative measure
of how long you can stay in the sun before getting burned. An SPF of 30
is the minimum recommendation by the American Academy of Dermatology.
So, if a person normally burns in 10 minutes, an SPF 30 would give them
30 times 10 minutes in the sun, if applied correctly. Often it is not
applied correctly. In fact, 53 percent of people surveyed by Consumer
Reports said they rarely or never use sunscreen.
One additional word of caution; over a four-year period, Consumer Reports
put more than 50 sunscreens to the test, all with SPF 30 or higher, to
see if they met their advertised SPF claims listed on the bottle. They
found 43 percent of them did not meet their SPF claim. Some missed it
by a lot. So be sure to not only put it on but reapply, reapply, reapply.
Consumer Reports submitted its four-year results to the Food and Drug Administration
(FDA), asking that it review its sunscreen requirements and investigate
further. The FDA doesn’t routinely test sunscreens but do require
manufacturers to test their products a product rolls out to the consumer,
or is reformulated. Even then, the companies don’t have to submit
their results and are required only to keep them on hand in the event
the FDA asks to review them.
What can you do in the meantime?
- True SPF 30 blocks 97 percent of UVB rays, and SPF 50 blocks 98 percent.
- Look for sunscreens with an SPF of 40 or higher with chemical active ingredients
like avobenzone—that will give you the best chance of getting an SPF 30.
- Use those sunscreens which give both UVA and UVB protection daily (UVA
being the most potent) even on cloudy days.
- 90 percent of skin damage (premature skin aging) is caused by UV exposure.
- Stay in the shade, especially during the hours of 10 a.m. - 4 p.m.
- Wear clothing that covers your arms and legs.
- Wear sunglasses that block both UVA and UVB rays.
- Avoid indoor tanning.
Look at your own skin every month. If you recognize changes in moles and
skin growths, call your primary care doctor or dermatologist - especially
if you have a history of skin cancer or melanoma. The good news about
skin cancer is that it's totally curable, if detected early.
If you have concerns about your skin, please feel free to set an appointment
with one of
St. Mary's Medical Group primary care providers listed:
Blue Springs Internal Medicine, 816-228-9841
Family Medical Care Associates, 816-228-1000
Oak Grove Medical Clinic, 816-690-6566