"Sunscreen Causes Cancer": Truth or Fiction? | The Survival Doctorby James Hubbard, MD, MPH

I didn’t realize until a few days ago how prevalent the view is—at least on the Internet—that sunscreen causes cancer. Many people state the claims of dangers as given facts. And they say organizations like the American Medical Association stand behind them. (Not true. I don’t know of any mainstream medical organization that recommends against sunscreen when you’re in the sun.)

The truth matters here. Because not even the fiercest critics of sunscreen debate against the fact that absorbing too many UV rays from the sun is a big risk factor for skin cancer.

So, should you use sunscreen or not? And what are the most common concerns?

I went on a fact-finding mission to glean the latest studies on the alleged sunscreen dangers. Here, I share what I found so you can make a more informed decision.

Alleged Sunscreen Dangers: Truth or Fiction?

 

Alleged Sunscreen Danger #1
Oxybenzone, a chemical found in many sunscreens

Claim: Oxybenzone is a known endocrine disrupter, which means it interferes with the production of some hormones. Endocrine disrupters can cause cancer. In fact, studies have shown oxybenzone causes cancer in mice.

 

Common rebuttal: In the study usually cited, oxybenzone was fed to mice. Yes, there was increased cancer in the exposed mice, and yes, the oxybenzone in sunscreen can be absorbed through the skin—but in much, much smaller concentrations. No study has ever shown oxybenzone to cause cancer in humans.

You can find more information from the American Academy of Dermatology here and here.

Alleged Sunscreen Dangers: Truth or Fiction?

 

Alleged Sunscreen Danger #2
Retinyl palmitate, a form of vitamin A found in some sunscreens

Claim: Retinyl palmitate lotion (without the sunscreen component) was applied to the skin of mice that were then exposed to UV light for several hours per day. These mice had more skin cancers than the ones who didn’t have the retinyl palmitate applied. The implication is that retinyl palmitate plus sunshine can cause cancer.

Rebuttal: Decades of studies exposing mice to a myriad of potential dangers have proven time after time that just because a product causes harm in mice doesn’t mean it does the same in humans.

The American Academy of Dermatology decided that because of the way the study was done (on a type of mouse already susceptible to skin cancer and by exposing the mice only to retinyl palmitate, not a mixture of ingredients found in suntan lotion), it cannot be concluded that cancer would be a risk in exposed humans. In fact, the AAD says there is more evidence to suggest retinyl palmitate protects against skin cancer in humans than that it causes it. Still, if it’s a worry for you, it’s fairly easy to find a sunscreen that doesn’t contain this chemical.

Alleged Sunscreen Dangers: Truth or Fiction?

 

Alleged Sunscreen Danger #3

Claim: Sunscreen has not been shown to prevent skin cancers, so why risk using it?

Rebuttal: A large, well-designed Australian study published in the Journal of Clinical Oncology revealed a 50-percent reduction in melanomas in people who applied sunscreen on a regular basis. (Melanoma is a dangerous and often deadly skin cancer.)

The key is to apply the sunscreen correctly and regularly:

  1. Apply liberally to all bare skin areas. Don’t forget the face and the back of the neck and legs. For an average-size body, that will take about an ounce of sunscreen.
  2. Reapply every two to three hours. If you’re sweating a lot or get in water, even sunscreen touted as “water-resistant” should be reapplied every 40–80 minutes. (The exact recommendation should be on the container.)

Alleged Sunscreen Dangers: Truth or Fiction?

 

Alleged Sunscreen Danger #4

Claim: Sunscreens give a false sense of complete protection, so you stay in the sun longer.

Rebuttal: Yes, that’s a possibility everyone should consider. Even if used ideally, no sunscreen protects 100 percent.

Only use sunscreen that has an SPF between 30 and 50. Reapply as recommended above. That should screen out well over 90 percent of the UV rays. For additional protection, take the following precautions:

  1. Wear a hat. Also consider wearing long sleeves and pants. (Clothing doesn’t protect 100 percent either).
  2. Don’t stay out in the sun for long periods. Ideally, stay inside between 10 am and 4 pm.
  3. Don’t let clouds fool you. At best, they’ll screen out a relatively small percentage of the UV rays.

OK, I know what you’re thinking: What about spending a day at the beach? Well that’s up to you. The beach is great fun; you just have to decide how much risk you’re willing to take. (Tip. Before you decide, remember the UV rays also speed up skin aging. Have a gander at the skin of those tanaholics who have reached their 50s and beyond.)

Alleged Sunscreen Dangers: Truth or Fiction?

 

Alleged Sunscreen Danger #5

Claim: The UV rays on your skin are essential in your body’s vitamin D production. If you’re vitamin D deficient, you’re at risk for all sorts of health problems, including cancer.

Rebuttal: It’s a dilemma without an easy answer.

If you’re light-skinned, after about 15 minutes of full sun your body has about maxed out on all the vitamin D it can produce. So a day in the sun without sunscreen won’t do you any more good than 15 minutes—and it’ll do a lot of harm.

However, the darker your skin, the more sun it takes for you to make the maximum amount of vitamin D. And this is where the dilemma comes in because the more sun exposure you get, the more you increase your skin cancer risk.

Perhaps you might find a compromise. Maybe take a short walk daily or every other day wearing shorts, short sleeves, and no sunscreen. Or perhaps take little longer walk in the early morning or late afternoon, when the sun isn’t as harsh. Or maybe apply a light layer of SPF 15 if you’re not going to be out too long.

Whatever you do, don’t you dare burn. I’d suggest you not even get much of a tan. And remember, you also get vitamin D from your food. But just to be safe, I’d add a supplement. Recommendations range from 600 IU to 1,500 IU daily. People with dark skin almost always need a supplement. (Talk to your doctor.)

Alleged Sunscreen Dangers: Truth or Fiction?

 

Undisputed Facts

  • UV rays from the sun increase your risk for skin cancers.
  • Hats and cover-up clothing are great but don’t screen out all the UV rays either.
  • In the U.S., one out of five people gets skin cancer.
  • One out of 58 gets the most deadly skin cancer, melanoma.

The Environmental Working Group has been the most active in raising the sunscreen dangers alarm. But even they don’t deny the dangers of too much sun. Here’s the list of sunscreens they recommend.

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Sunscreen photo: Flickr/miss pupik. Sun photo: Flickr/Jalal Hameed Bhatti