Sunscreens: The Ugly Truth

By Dr. Mercola

For decades, doctors and the media have recommended you apply sunscreen before going outside.

According to the American Academy of Dermatology (AAD), everyone should use sunscreen for protection from the sun's ultraviolet rays, believed to be the trigger for skin cancer and the precursor to wrinkles and premature aging.¹

However, the recommendations don't include the kind of sunscreen that is effective, nor do the recommendations advise you how to use the sun effectively to protect yourself from skin cancer and improve your vitamin D level, which has significant health benefits, including a lowered risk of melanoma.

To date, the U.S. Food and Drug Administration (FDA) does not have regulations governing advertising and claims for sunscreen.² In 2011, the FDA banned the use of terms on sunscreen making inflated claims, such as "all day protection" and "sweat-" or "waterproof."

The Environmental Working Group (EWG) recently released their 2016 list of best and worst sunscreens³ based on criteria such as level of protection and safety of the product, to guide your use of sunscreens this season.

Just remember, companies can change their ingredients, so always read the labels of the products you purchase.

Are Sunscreens the Right Way to Prevent Sunburn and Skin Cancer?

Despite the availability of sunscreen products and media coverage about using sun protection, the number of people suffering from malignant melanoma of the skin continues to rise each year. The number of new cases of skin cancer per 100,000 people has risen from 7.9 in 1975 to 24 people in 2013.⁴

This represents a consistent average 3 percent rise each year in newly diagnosed cases and a 200 percent rise from 1975 to 2013. 

Ultraviolet radiation reaches the earth as UVA and UVB light, and has been classified as a human carcinogen by the National Toxicology Program (NTP).⁵ UVA is generally considered to be less carcinogenic than UVB.

Because it was believed UVB light was more dangerous, sunscreen products were first developed to filter UVB and not UVA. However, recent research has demonstrated UVA radiation actually plays an important role in the development of malignant melanoma, the most aggressive form of skin cancer.

According to estimates, more than 144,000 Americans will be diagnosed with melanoma in 2016, with five-year survival rates starting at 98 percent if the cancer has not reached the lymph nodes, 63 percent for regional cancer and dropping to 17 percent for distant-stage melanoma.⁶

A number of studies demonstrate sunscreen reduces the number of new squamous cell skin cancers, but has no effect on basal cell and may actually contribute to the development of the more aggressive malignant melanoma.⁷

There is some evidence that non-melanoma and easily treated skin cancers are related to cumulative exposure to the sun. However, that is not the case with malignant melanoma, linked with significant sunburns.⁸

The American Cancer Society recommends sunscreen should be used as a filter, and not a reason to stay longer in the sun. For extended outings, they recommend other methods of sun protection, even when properly using sunscreen, such as hats, sunglasses, clothing and shade.⁹

The Good, the Bad and the Ugly

Surveys from the AAD have demonstrated that many are not aware of how to use the sunscreen effectively.¹⁰ However, even when used correctly, not all sunscreen products contain what's advertised on the bottle.

In one test, researchers evaluated the SPF value of 65 different products to find 43 percent had less SPF than promised on the label.¹¹

Sunscreen also blocks your body's ability to manufacture vitamin D, although several studies have demonstrated that most people don't use adequate amounts of sunscreen to negatively affect their vitamin D levels.^12,13,14,15 Still, this certainly is a concern, especially if you wear sunscreen all the time.

In such a case, you may want to consider getting your vitamin D level tested, and if below the clinically relevant level of 40 nanograms per milliliter, you'd be wise to consider a vitamin D supplement. Still, supplements cannot provide the identical benefits of sensible sun exposure.

The amount of sunscreen needed to protect your skin from burning also increases the amount of toxic chemicals you use.

Even studies from the Centers for Disease Control and Prevention (CDC), demonstrate 97 percent of people living in the U.S. are contaminated with a toxic ingredient widely used in sunscreens, called oxybenzone.¹⁶

Oxybenzone is commonly found in sunscreens and other personal care products. EWG identified nearly 600 different sunscreen products containing oxybenzone.

Mothers with high levels of the chemical have a higher risk of giving birth to low birthweight babies, a critical risk factor linked to cardiovascular disease, diabetes, hypertension and other diseases.¹⁷

What Do the Numbers Really Mean?

Sunscreens may also give you a false sense of security. Many consumers believe the higher the SPF number, the greater the protection against UV radiation. However, as mentioned earlier, most sunscreens protect against UVB but don't have adequate protection against UVA radiation.

Both UVA and UVB can cause tanning and burning, although UVB does so far more rapidly. UVA, however, penetrates the skin more deeply than UVB, and may be a much more important factor in photoaging, wrinkles and skin cancers.

An SPF of 30 will theoretically filter 97 percent of the UVB rays for two hours.¹⁸ Theoretically, a higher SPF will block more of the sun's UVB rays, but no sunscreen will block 100 percent.

The problem is, if you're not experiencing skin reddening, you may be tempted to prolong the time you stay in the sun. This raises your risk of overexposure, which is the real danger with sun exposure.

Sunscreens with a higher SPF also require more chemicals to achieve the intended result. Many pose a health risk when they are absorbed through the skin, potentially causing tissue damage and disrupting your hormonal balance.

Because you don't experience better protection with higher SPF numbers, it's usually best to stick with SPF 30 if you choose to use sunscreen.

How They Work

In order for sunscreens to be effective, you must apply large amounts over all exposed areas of your skin. This means the product should not trigger skin allergies and must provide good protection against UV radiation. It also should NOT be absorbed into your skin, as the most effective sunscreen acts as a topical barrier.

Sunscreens work based on one of two mechanisms. Older products sat on the top of your skin, causing UV rays to bounce off. Most contained zinc oxide or titanium dioxide.

The second type uses chemical filters to block UV radiation. Many of those include octisalate, oxybenzone, avobenzone, homosalate, octinoxate and octocrylene.¹⁹

Several of these chemicals are hormone disruptors that have been shown to alter reproductive ability, delay puberty, alter estrous cycles in mice, reduce sperm counts in animal studies, and alter thyroid function.

Other chemicals, such as retinyl palmitate, may actually increase your risk of developing skin cancer. This product is a form of vitamin A that may speed the development of tumors and lesions when exposed to sunlight.

Manufacturers sometimes add it to products to slow skin aging.²⁰ However, that only holds true in the absence of sun exposure.

Mechanical sunscreens, including zinc oxide, have proven over years of use to be a safe and effective means of blocking both UVA and UVB light.²¹

In light of recent media coverage, some companies are using zinc oxide to block UV radiation, while attempting to meet the desire of their consumers for products that don't leave a thick film on the skin.

Nanotechnology and What It Does

To reduce the thick film, manufacturers are reducing the size of the molecules. This nanotechnology has several different effects. The particles are so small they may be absorbed into your skin. Some studies have found significant negative health effects from the absorption of nanoparticles.²² While excellent as a drug delivery system, it is questionable for use in sunscreen.²³

Reducing the size of the zinc oxide particles improves the UVB protection but reduces the UVA protection, one of the important benefits of using zinc oxide as a sunscreen.²⁴ Zinc oxide is beneficial because it remains stable in heat, but as a nanoparticle, the problems with toxicity probably outweigh the benefits to sun protection.

Toxicity of zinc oxide nanoparticles, after systemic distribution, may affect your lungs, liver, kidneys, stomach, pancreas, spleen, heart and brain.²⁵ Findings have also demonstrated that aging has a synergistic effect with zinc oxide nanoparticles on systemic inflammation and neurotoxicity, affecting your brain and neurological system. In other words, the older you are, the higher your risk of neurotoxicity from zinc oxide nanoparticle absorption.

Is Sunscreen a Scam?

Until around 1950, melanoma was rarely diagnosed. The numbers didn't rise until the late 1960s, just after "tanning lotion" was introduced on the market. The idea behind the lotion was the longer you could stay in the sun without burning, the more likely you would tan.

The standard explanation for the rare diagnosis of melanoma prior to the 1970s was that Americans started sunbathing in earnest in the 1950s. However, any image of the beaches from the 1930s and earlier would demonstrate that people enjoyed the sun and ocean long before the 1950s. The higher the rates of melanoma diagnosed per year, the greater the call to use sunscreen.

Interestingly, the prognosis or outcome of a diagnosis of melanoma may be linked to your levels of vitamin D. In a ground-breaking study, researchers demonstrated a link between levels of vitamin D and outcomes in individuals diagnosed with melanoma, after adjusting for C-reactive protein levels.²⁶

Prior studies demonstrated a link between C-reactive proteins and poor outcomes after diagnosis with melanoma. This study looked at the association between vitamin D, an inflammatory response, and C-reactive proteins in a sample of over 1,000 patients. An investigation of several biomarkers suggested increasing vitamin D may improve five-year survival rates.

From the Inside Out

You can boost your internal ability to offset UVA and UVB radiation through the nutrients you eat each day. Antioxidants found in colorful fruits and veggies have been shown to have protective effects, but the real "superstar" is the fat-soluble carotenoid astaxanthin, which is what gives krill, salmon, and flamingos their pink color.²⁷

Astaxanthin is produced by the microalgae Haematococcus pluvialis when its water supply dries up, forcing it to protect itself from ultraviolet radiation. It is this "radiation shield" mechanism that helps explain how astaxanthin can help protect you from similar radiation.

When you consume this pigment, you are essentially creating your own "internal sunscreen." Research has confirmed it's a potent UVB absorber that helps reduce DNA damage. It's actually one of the most potent antioxidants known, acting against inflammation, oxidative stress and free radical damage throughout your body.

Each of these functions improves the ability of your skin to handle sun without burning, while giving your body the best advantage to manufacturing vitamin D. This is not a free pass to spending all day in the sun without physical protection, such as hat and long-sleeved clothing, but it does give you a healthier option than using chemicals to filter UV radiation.

Your Best and Worst Sunscreen Choices

Your safest and best choice for sunscreen protection is zinc oxide. Avoid nano versions however, to circumvent potential toxicity. Unfortunately, it can be challenging to find a product without other chemically based sunscreen filters. To help you choose the product best for your family, EWG performs an annual sunscreen evaluation based on effectiveness and safety.

Sixty brands received the EWG's low-hazard ingredient list ranking this year. Their report published the best and worst choices for children, but only the best choices for adults.^28,29,30 Here's a sampling of the best and worst:

Best for Adults and Children

Worst for Children