If you ask dermatologists who needs sunscreen? The answer is automatic: EVERYONE! The official word from the American Academy of Dermatology (AAD) is that “Sunscreen use can help prevent skin cancer by protecting you from the sun’s harmful ultraviolet rays.” You cannot get any clearer than that. But does slathering on the sunscreen prevent skin cancer? Is there solid scientific proof to support the AAD position that you should use sunscreen every day you are outside and reapply it every two hours.
A Reader Had a Seemingly Simple Question: Will Sunscreen Prevent Skin Cancer?
We stirred up a hornet’s nest when we answered a reader’s question about sunscreen. He wrote:
“It seems to me that sunscreens may prevent burning, but I’m not sure they prevent skin cancer. The incidence of all types of skin cancer has increased since sunscreens were introduced.”
When we went searching for solid scientific proof that vigorous sunscreen use prevents skin cancer, we were shocked to discover that we didn’t find much. We assumed that there would be dozens of large, well-controlled clinical trials designed to answer the question: does sunscreen prevent skin cancer?
The Cochrane Database of Systematic Reviews:
The first place we searched was The Cochrane Database of Systematic Reviews (July 25, 2016). This organization is one of the most independent and trusted sources of medical evidence. Read about Cochrane at this link.
In trying to answer the question does sunscreen prevent basal or squamous cell skin cancer, the authors reviewed the available literature and found only one study worthy of analysis:
“We included one RCT [randomized controlled trial] that randomised 1621 participants. This study compared the daily application of sunscreen compared with discretionary use of sunscreen, with or without beta-carotene administration, in the general population. The study was undertaken in Australia…”
“In this review, we assessed the effect of solar protection in preventing the occurrence of new cases of keratinocyte cancer. We only found one study that was suitable for inclusion. This was a study of sunscreens, so we were unable to assess any other forms of sun protection…
“We were unable to demonstrate from the available evidence whether sunscreen was effective for the prevention of basal cell carcinoma (BCC) or cutaneous squamous cell carcinoma (cSCC).”
What About Sunscreen vs. Melanoma?
Basal cell and squamous cell carcinoma are serious cancers, but they are common and rarely life-threatening if discovered early and treated appropriately. Melanoma is a different matter. This skin cancer can be lethal. That is why it is so important to try to prevent melanoma.
Another meta-analysis examined whether sunscreen use reduces the risk of melanoma and non-melanoma skin cancer. The outcome was also inconclusive (European Journal of Dermatology, April 1, 2018). The authors wrote:
“While the current evidence suggests no increased risk of skin cancer related to sunscreen use, this systematic review does not confirm the expected protective benefits of sunscreen against skin cancer in the general population.”
Dermatologists Are NOT Happy with Us!
Not surprisingly, some dermatologists were dismayed by this message. One wrote:
“After spending over 40 years treating skin cancer and counseling patients on sunscreen use, I feel that the ‘data’ you reported needs interpretation in real life terms.
“Sunscreen use in many studies does not necessarily mean adequate use. A good British study done years ago showed that the average person applies only about 25 percent of the recommended amount of sunscreen. I suspect that the subjects in the studies you cited did not apply sunscreen half an hour before going outside, reapply it every two hours, or put it on more often if they were swimming or perspiring.
“My favorite advice to patients is if you can see without a flashlight, you should have sunscreen on.”
Not Enough Sunscreen?
One reader shared the dermatologist’s skepticism about the sunscreen studies. She wrote:
“What if the positive correlation between sunscreen use and skin cancer were caused by overconfidence of sunscreen slappers-on so that they stayed in the sun much longer than the non-slappers-on? Did the studies include average time spent in the sun, and time of day outdoors?”
She might very well be right.
Another reader chimed in:
“As a result of reading your article, I checked the labels on all our sunscreen bottles. They claim to prevent sunburn but say nothing about skin cancer.”
Avoiding the immediate pain of a sunburn is in itself worthwhile. But if we want to prevent the much greater and longer-lasting harm of skin cancer, especially life-threatening melanoma, we’ll need better research to answer the question: Does sunscreen prevent cancer?
The American Academy of Dermatology should sponsor a very large, well-controlled clinical trial (with optimal sunscreen applications) to show us whether sunscreens are truly effective at preventing skin cancer!
We live in an era of “evidence-based medicine.” That means physicians are supposed to rely on solid science to inform their recommendations. The public deserves better research when it comes to sunscreen to prevent skin cancer.
While We Wait:
In the meantime, perhaps we should all follow some simple common-sense approaches. Don’t go out in the sun between 10 and 2, when you are more likely to suffer a sunburn.
To encourage you to follow this challenging advice, take 30 seconds to listen to this famous Noel Coward song:
Use a hat with a brim, a long-sleeved shirt and long pants for protection if you must venture out. (If that sounds too hot, as well as too old-fashioned, look for some of the specialty clothing that has ultraviolet protection built in.)
When you put on your hat, don’t forget your sunglasses. And be aware that some popular medications may increase the likelihood of a sunburn. The diuretic hydrochlorothiazide (HCTZ) for example has been linked to an increased risk of squamous cell skin cancer (Journal of the American Academy of Dermatology, April, 2018).
Read more about HCTZ and skin cancer at this link:
Share your thoughts about sunscreen in the comment section below. We especially welcome data from dermatologists that might answer the question: does sunscreen prevent skin cancer?
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Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio. Here is a link to the podcast so you can subscribe for free.