The dangers of sunscreen / June 30, 2013

Sunscreen © Copyright 2010 CorbisCorporationIt’s that time of year again when the sun begins to shine and parents reach for the sunscreen. We are told that sunscreen will protect us from sunburn, wrinkles, and skin cancer. Yet, research now suggests that sunscreen might not do any of these things very well: instead, many of the most popular sunscreen brands might actually increase our children’s chances of getting some cancers.


The issues with sunscreen

The FDA says it is “not aware of data demonstrating that sunscreen use alone helps prevent skin cancer,” according to a 2010 Huffington Post article.  It gets worse. A 2007 meta-analysis of 17 (out of 18 known) studies on the subject concluded that: “there was no statistically significant effect of use of sunscreens on risk of melanoma.” The study further found that in latitudes greater than 40 degrees (New York and north—i.e. Vancouver and all the rest of Canada) the use of sunscreen might actually “contribute to the risk of melanoma.”  (Malignant melanoma is the deadliest of skin cancers accounting for about 4% of skin cancers but 75% of skin cancer related deaths.)

Sunscreens are effective at blocking UVB rays, but do not do such a good job of blocking UVA rays. The skin doesn’t get “burnt” because the burning rays are blocked, but it still gets zapped. So, though sunscreens are effective at reducing the risk of squamos-cell carcinoma (associated with exposure to UVB rays), this is neither particularly abundant (at 16% of skin cancer cases) nor particularly deadly. UVB rays are also the ones associated with Vitamin D production in the body. No one seems to know for sure if this is why sunscreen wearers have as much or more chance of developing melanoma. These problems don’t even take into account that many sunscreens contain known cancer-causing ingredients.

Dirty sunscreen

In an independent investigation, EWG researchers reviewed 500 popular sunscreens and recommended only 39 of them as safe for consumers. The worst offenders were often the market leaders:   None of the 39 received a perfect score. Even worse, they found that many brands made inaccurate and misleading claims such as “water-proof,” “broad-spectrum protection,” and even “chemical-free.” Other words to be wary of: “for babies,” “natural,”  and any SPF over 50.  Many sunscreens, including those marketed specifically to children and babies, had known carcinogens, neurotoxins, ingredients known to become unstable and reactive when exposed to sunlight, and chemicals linked with endocrine disorders (gender-bending effects), and birth defects.  Some of the worst offenders include the more popular brands (Neutrogena, No-Ad, Coppertone, Banana Boat) and there packages were littered with the above-mentioned meaningless statements.

The FDA recently updated its sunscreen regulations for the first time in 33 years. They went into effect in December 2012. Around the same time, Canada updated their monograph (which is not legally binding) on how companies should label their sunscreen products. Yet, according to the independent researchers at EWG, things may have gotten worse for North American sunscreen users since.

Ingredients to watch for in sunscreen and the challenges of reading sunscreen labels.

There are two types of sunscreens available in North America. Chemical sunscreens rely on chemicals to filter UV rays. Research suggests that these chemical filters are easily absorbed through the skin and into the body and that they can cross the placenta and enter unborn children. The most commonly used of these chemical filters, oxybenzone, can cause allergic skin reactions and may disrupt hormones. Mineral sunscreens are also available and they tend to rely on zinc oxide and titanium dioxide to filter UV rays. The EWG says that mineral sunscreens usually rate as safer in their research, however most of these mineral filters are used in nano particle form. This means the ingredients are so small that they can enter the bloodstream and may cause damage to internal organs. Zinc oxide is probably the safest sunscreen available, but in order for it to not look white and greasy, it is usually made into a smaller nano-particle form which provides less UVA protection.

In the U.S. and Canada sunscreens are regulated as drugs. This means it has taken longer for both of the countries to approve some of the newer chemicals currently in use in the E.U. and Japan and thought to be safer and provide more UVA protection, including: Mexoryl SX, Tinosorb S and Tinosorb M. This also means sunscreen companies are not required to list all their ingredients on the labels in either country.

Avoid these sunscreen ingredients:

Fragrance or Parfums are considered trade secrets in both the U.S. and Canada, so dozens of chemicals—including suspected neurotoxins and endocrine disruptors—can be hidden behind these seemingly innocuous terms.

High SPF factors. High SPF ratings were found by the FDA to be “inherently misleading.” These high-SPF products often contain more of the above offending ingredients and can encourage people to stay in the sun longer without providing any additional protection.

Nanoparticles. Micronized or nanoscale particles of minerals are often found in titanium or zinc based sunscreens. These tiny particles have not fully been studies and there are no regulations governing their use or labelling in the U.S.

Oxybenzone. Found in almost all chemical sunscreens, oxybenzone is an allergen, potential endocrine disruptor. It is easily absorbed through the skin, particularly in children, and can interphere with hormone development.

Parabens. Parabens, such as methyl paraben and butyl paraben, are endocrine-disrupting chemicals that mimic the female hormone estrogen and are linked with reproductive disorders in boys and possibly cancers in women.

Para-aminobenzoic acid (PABA) has mostly been phased-out of sunscreens because of high incidence of allergic reactions in response to its use.

Retinol or retinyl palmitate. Found in many name-brand sunscreens, this type of Vitamin A is photocarcinogenic and might actually speed the development of skin tumors and lesions.

All spray sunscreens. When sunscreen is sprayed, it can be inhaled, where it can do damage to the lungs. Even mineral sunscreens aren’t safe in spray form as titanium dioxide becomes a “possible carcinogen” when inhaled in high doses (IARC 2006).


More research on sun exposure, UV rays, & Vitamin D

The science of sun-light  

Ultraviolet (UV) light is divided into 3 wavelength ranges that are referred to as UVA, UVB, and UVC rays. UVC is the most energetic and shortest of the UV rays. It burns quickly and in small doses. It is also absorbed entirely by the ozone layer. Thus when talking sunscreen, we are primarily dealing with UVA and UVB rays.

UVB is the UV ray that is primarily responsible for sunburn. It also stimulates the body’s production of Vitamin D; melanin, which protects human skin from sun damage; and Melanocyte Stimulating Hormone (MSH), an important hormone in weight loss and energy production. Only 5% of the UVB light range goes through glass and it does not penetrate clouds, smog, or fog. Most sunscreens only protect against UVB rays and the SPF (sun protection factor) rating refers to efficacy in protecting against UVB light.

UVA is primarily responsible for aging and darkening the pigment in our skin. UVA is less energetic than UVB, but has a longer wavelength. This means UVA rays penetrate deeper. UVA rays are less likely to cause sunburn, however UVA rays are now considered to be a major contributor to non-melanoma skin cancers. Until recently, UVA was not filtered by sunscreens (and still isn’t filtered by most sunscreens sold in America) and 78% of UVA can even penetrate through glass windows. UVA sunscreen ratings are measured by PPD (persistent pigment darkening), theoretically a rating of 10 would allow you to stay out 10 times longer.



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