Natural Sun Protection

By Bonnie Jenkins, Advanced Natural Medicine

About this time every year, magazines and newspapers roll out their annual sun safety articles – and with good reason. According to the American Cancer Society, an estimated 60,000 people will be diagnosed with some form of skin cancer this year alone. Of those, more than 10,000 cases will prove fatal.

Prevention is key, since researchers believe that even one sunburn early in life can lead to cancer later on. And continued exposure simply boosts the odds for sun worshippers. To prevent becoming one of the statistics, most dermatologists recommend a generous daily dose of sunscreen.

The problem is, if preventing skin cancer is the goal, they may be giving the wrong advice.

Prevention or Cause?

Just when people have become convinced that sunscreen can protect them from developing skin cancer, new evidence is casting a shadow of doubt about the safety and effectiveness of these products.

The controversy stems from a parallel rise in skin cancer and sunscreen use. In 1998, epidemiologist Merianne Berwick of New York’s Memorial Sloan-Kettering Cancer Center, presented an evaluation of several studies on sunscreen use and cancer to the American Association for the Advancement of Sciences. Her conclusion: There is no scientific evidence that the use of sunscreen prevents skin cancer – and five of the studies Dr. Berwick cited found that sunscreen users actually had an increased risk of melanoma.

While some experts believe that sun worshippers use sunscreen as an excuse to spend an unhealthy amount of time in the sun, others suspect that the ingredients in sunscreen may be the culprit. In the late 1990s, John Knowland, Ph.D., of the University of Oxford reported that sunscreens containing Padimate-O can damage DNA when exposed to sunlight. Because this commonly used chemical behaves like a mutagen, Dr. Knowland concluded that some sunscreens could, while preventing sunburn, actually contribute to sun-related cancers.

More recently, scientists have found that sunscreen ingredients also promote cancer by generating free radical damage. (You might remember that free radicals are unstable molecules that cause cellular damage by stealing electrons from healthy cells, a process called oxidation.) One chemical of particular concern is oxybenzone. Not only does oxybenzone cause oxidation, German researchers have discovered that it inactivates important antioxidant systems in the body that suppress free radical damage.

Margaret Schlumpf and her colleagues at the University of Zurich, Switzerland, have also found that many widely-used sunscreen chemicals mimic the effects of estrogen and trigger developmental abnormalities in rats. Her group tested six common chemicals used in sunscreens and found that five of them (benzophenone-3, homosalate, 4-methyl-benzylidene camphor (4-MBC), octyl-methoxycinnamate and octyl-dimethyl-PABA) behaved like a strong estrogen in lab tests and caused cancer cells to grow more rapidly.

Block Party

Fortunately, Mother Nature has supplied her own UV screening agents. Zinc oxide and titanium dioxide are natural minerals that, when incorporated into creams, create a physical barrier on the skin. Unlike chemical sunscreens which absorb UV light, these sunblocks scatter UV rays away from the skin’s surface. Often paired in natural sun protection products with mild botanical sunscreens like shea butter, wild pansy, green tea and coffee extracts, these minerals safely protect against both UV-A (which promotes melanoma, the deadliest form of skin cancer) and UV-B rays.

What’s the difference between these two types of sunlight? UV-B rays are the ones that cause sunburn – and the ones dermatologists have always considered most dangerous. But Australian and American scientists have now discovered that UV-A (the tanning rays) may be an even greater threat.

According to the researchers, while UV-B rays damage DNA in the basal or upper layers of the skin, UV-A induces a greater number of mutations in the deep layer of skin, where skin cancers are born. While most chemical sunscreens have started adding ingredients that protect against both types of light, these synthetic UV-A protectors may not be any safer than the dubious chemicals used to absorb UV-B rays.

Better Advice

Even though sunblock sounds like armor against the sun, if you don’t use it properly, you might as well wear nothing at all.

Apply your sunblock at least a half-hour before heading outdoors to give the product a chance to bond with the skin. And don’t be miserly when slathering it on. The Skin Cancer Foundation recommends using at least one full ounce, or the equivalent of a shot glass, for head-to-toe protection.

You can also protect yourself from the inside-out. A randomized study of 101 skin-cancer patients by Baylor University’s department of dermatology in Houston, Texas found that reducing dietary fat to no more than 20 percent caloric intake lowers the occurrence of non-melanoma skin cancer. What’s more, a clinical trial of 115 skin cancer patients found that adopting a low-fat diet, even after cancer-causing sun exposure, significantly reduced the incidence of developing basal and squamous cell cancers — good news for people with a personal history of the disease.

One Last Thing ...

If prevention is important, so is getting an annual screening for skin cancer. It’s also vital to regularly check your skin between screenings. When skin cancer is detected early, it’s almost always curable.

Once a month, check over your whole body and look for changes in moles and birthmarks. Be alert to irregularities in the shape, edges, color, and size. The Skin Cancer Foundation offers a terrific guide to help you do a thorough self-exam. You can find it at www.skincancer.org and I strongly urge you to check it out. If you do find irregularities or changes, have them checked by a dermatologist immediately.

This Just In ...

If exercise leaves you exhausted, you might be running low on magnesium. A new study by the USDA’s Agricultural Research Service found that adequate levels of the mineral are essential when exercise has you’re body craving extra oxygen. During the study, 10 postmenopausal women were fed a diet containing adequate magnesium. After 35 days, they switched to a low-magnesium diet containing just half the recommended daily amount. Three months later, the women were again given the magnesium-rich diet. After each dietary change, the volunteers were subjected to exercise tests, along with biochemical and physiological tests.

The researchers found that when magnesium levels were depleted, the heart and muscles had to work harder. And this doesn’t just apply to vigorous workouts. Even low-level activities like housework can put a strain on your body if your magnesium levels are low.

You can boost your levels by including more magnesium-rich foods in your diet, especially nuts, beans, green leafy vegetables, shellfish and whole grains. But, since diet alone may not give you enough magnesium, it’s a good idea to take a daily dose of 250 to 350 mg. in supplemental form.

It may just be the easiest way to improve your workout!

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References:

Bliss R. “Lack Energy? Maybe It’s Your Magnesium Level.” Agricultural Research Magazine. 4 May 2004.

Knowland J, et al., “Sunlight-induced mutagenicity of a common sunscreen ingredient,” FEBS Letters. 1993;324:309-313.

McHugh PJ. “Characterization of DNA damage inflicted by free radicals from a mutagenic sunscreen ingredient and its location using an in vitro genetic reversion assay.” Photochemistry and Photobiology. 1997;66:276-281.

Nita S, et al. “The basal layer in human squamous tumors harbors more UVA than UVB fingerprint mutations: A role for UVA in human skin carcinogenesis.” Proceedings of the National Academy of Sciences. 2004;101:4954-4959.

“Sunscreens May Not Protect Against Melanoma Skin Cancer,” Memorial Sloan-Kettering Cancer Center Press Release. 17 Feb 1998.