Can Using a Sunscreen Be Worse than Using a Tanning Bed? The Health Implications of a UVB Biased Sunscreen.

The New Study that Shows How a UVB Sunscreen Can Be Worse than a Tanning Bed

The Role of Long Wave UVA in Skin Cancer

There is an unrelenting rise in skin cancer rates in North America with an annual increase around 2-3 % over the past 3 decades. In the UK there was an alarming increase of 40% in the past 4 years. Empirical analysis of global skin cancer rates suggest that rates are levelling off or decreasing in countries with higher UVA-Protection Factor (UVA-PF) levels in sunscreens (2015 Sunscreen Symposium, Florida, September 2015). The compelling evidence for the primary role of UVA - particularly the UVA1 or longwave UVA -  in the genesis of skin cancer – comes from a number of scientific studies over the past 15 years (Halliday 2002, Agar 2004, Noonan 2012, Rünger 2012). This is logical and intuitive as UVA is more abundant than UVB and penetrates deeper into the skin.

The primary objectives of photoprotection  must be to prevent rising rates for skin cancer, reduce health care expenditures for a disease with potentially preventable aspects, and to reduce other effects of UV radiation, like photoaging and immune suppression. The continual 2-3% annual rise in skin cancer rates for North America shows that the current approach has failed. Critical analysis argues that ineffective UVB biased sunscreens are an important contributory factor. Cancer prevention and immune protection  from sunscreens in humans is dependent on protection from UVA and cannot be predicted from the SPF (sun protection factor), more a measure of UVB attenuation.

There is  a logical and evidence-based argument that the exclusive use of balanced sunscreens, which provide spectral homeostasis or uniform protection at every wavelength can reduce cancer rates and photoaging. The current  science confirms that UVB causes direct DNA damage, whereas UVA results in direct DNA damage and indirect effects from ROS (reactive oxygen species), photoimmunosuppression, and disruption of repair mechanisms.  UVB initiates and modulates the damage cycle but UV (particularly UVA1) completes the process. Photoprotection with traditional UVB biased sunscreens with little or no UVA protection must now be abandoned and a new clinical strategy adopted by doctors and as a public health policy.

How Can A UVB Biased Sunscreen Do More Harm than Good?

There is another powerful bit of evidence that implicates the widespread use of UVB-biased sunscreens, with little or no UVA1 protection, in rising skin cancer rates and visible photoaging at younger ages. Daily use of UVB biased sunscreens that dominate the market, exposes the patient to asymmetric UVA1 radiation, similar to a tanning bed. More people develop skin cancer because of tanning than develop lung cancer because of smoking. One indoor UV tanning session increases users’ risk of developing squamous cell carcinoma by 67 percent and basal cell carcinoma by 29 percent. People who first use a tanning bed before age 35 increase their risk for melanoma by 75 percent.  

There is an important  parallel between the asymmetric UVA1 from tanning bed exposure and using a UVB-biased sunscreen, either on vacation or every day. This crucial fact escapes our regulators, most physicians including dermatologists, and the cosmetic industry. 

Vacation exposure over 2 weeks with typical sunscreens for protection could be double the radiation received from 10  eight minute tanning bed exposures. In extreme cases of recreational sun exposure where sunscreens providing suboptimal broad-spectrum protection are used, the UV insult to the skin is likely to result in higher cumulative exposures than commonly employed sunbed practices (Diffey et al).

This occurred to me several years ago but the science and physics was beyond my capability. I kept asking Uli Osterwalder- one of the authors in the study and a friend- about this obvious concern, until they finally did the calculations. It is a computer derived analysis that suggests the wrong sunscreen - UVB-biased - may be more dangerous than tanning bed exposure. Both provide asymmetric UVA radiation to your skin. There is another cautionary aspect to this. The vacation model is more acute and intense but what about everyday exposure if using a UVB-biased sunscreen? Many outdoor occupations reach or exceed the vacation exposure.

If tanning beds cause higher risks for skin cancer, then providing a patient with a UVB biased sunscreen that gives a similar UV radiation profile, relative to the right conditions of exposure and time, should also be considered as an undesirable measure. For doctors involved with rejuvenation, prescribing a balanced sunscreen that gives adequate UVA1 protection is a responsible practice standard. This is an integral part of post treatment care after rejuvenation procedures. Without balanced protection, the patient resumes accelerated photoaging from UVA1 exposure and the  treatment benefit is quickly lost. Repeat treatments will then be required more quickly. 

What Is A Better Alternative?

Adequate but safe UVA1 protection is only attainable with filters like zinc oxide (>20%), zinc oxide (>15%) plus 7.5% titanium dioxide or encapsulated octinoxate, bemotrizinol, and bisoctrizole – insoluble particle type filters with no entry into our bodies. Regrettably,  the last two safe and highly effective insoluble particle filters, have yet to be approved by Health Canada and the FDA, despite their global use in every other country over the past 15 years.

Most UVB-biased sunscreens use the soluble filters that penetrate skin into blood and even tissues like receptors in the brain. The group includes oxybenzone (benzophenone), homosalate, octisalate, octocrylene, non-encapsulated or regular octinoxate, and 4-methyl benzilidene camphor. They are more active in UVB and shortwave UVA (UVA2). Some UVA1 activity comes from avobenzone, another soluble filter that obtains tissue levels. It enters the body and is unstable in sunlight. Most parents and pregnant women are unaware that these filters (used in over 80% of our sunscreens) gain entry to our bodies, reason enough to avoid them.

There is a principle in endocrinology – isoform function – whereby chemicals with the same structure likely bind to the same hormone receptor and generally have the same effects. Hence avobenzone and octisalate very likely exert the same toxic effects as oxybenzone and homosalate, known to be hormone disruptors. Oxybenzone and its structural cousin avobenzone are now the leading causes of photocontact allergy (Warshaw 2012). A 2015 report (Downs et al) confirms other studies over the past decade that oxybenzone washing of sea-bathers is genotoxic, kills larvae of reproducing coral, and converts the planula from a motile to a sessile state by ossification. Oxybenzone found in 65% of our poses a hazard to coral reef conservation and threatens the resiliency of coral reefs to climate change.

Recommendations for Practitioners and Consumers:

You are faced with a simple choice in selecting a safe and effective sunscreen:

·       UVB- biased products with tiny soluble organic filters that give incomplete protection (inadequate UVA1 protection) and are implicated with adverse effects on our health and the environment. They are likely a root cause of rising cancer rates and early photoaging.

·       A balanced or truly broad spectrum sunscreen using insoluble filters, large particles that remain on the skin, have no known adverse effects on human health or the environment, and give you better protection, where the right combination can approach that of textiles and staying out of the sun.

·      Balanced sunscreens using insoluble particle type UV filters with no entry into blood of mother or fetus are safe to use in pregnancy. More egregious to me, is the fact that nearly all physicians fail to advise pregnant women and parents about percutaneous absorption of soluble filters and their possible hormone disrupting and carcinogenic effects. As a former obstetrician, I appreciate the persuasive simplicity that anything safe to use in pregnancy is safe to use for everyone.

9 Reasons Why Oxybenzone Might be One of the Most Dangerous Chemicals in Your House

As a former specialist in Maternal Fetal Medicine (MFM) and Reproductive Endocrinology, I believe the Endocrine Disrupting Chemicals (EDC’s) are already affecting human health and I stopped exposing my family some 30 years ago. Even if they were not harmful, soluble filters gain entry to blood, tissue and brain. In pregnancy they pass through the placenta and bind to the various hormone receptors in the embryo and fetus. This is a bad idea. The World Health Organization report confirms the serious threat that hormone receptors pose to humans and wildlife. What it does not say is the obvious corollary that in our society, soluble sunscreen filters and other small Molecular Weight (MW) sized chemicals smaller than 500 Daltons, like the preservative parabens, are the single most important source of exposure to EDCs.

  

Sunscreens and their role in our Health

Although hormone disruptors are affecting human reproductive and other endocrine systems, there is a simple way to avoid a major source of EDCs.   There is also a simple way to protect this and the next generation from rising skin cancer rates. 

There is a growing list of adverse effects linked to hormone disruptors that must include the soluble sunscreen filters – oxybenzone, avobenzone, homosalate, octisalate, octocrylene and others. 

Some of these adverse effects include the following reproductive disorders: 

• infertility
• polycystic ovarian syndrome
• endometriosis
• fibroids
• breast and uterine cancer
• prostate cancer
• oligospermia 
• male infertility

Non-reproductive disorders include:

• ADHD
• asthma
• Parkinson’s 
• Alzheimer’s
•  thyroid cancer

Each person should make their own choice between two classes of sunscreens. Either use a sunscreen with small molecular weight (MW) soluble filters less than 500 Daltons. They are absorbed through the skin to reach blood, tissue, and bind to some receptors in the brain. They also give incomplete or UVB-biased protection that may prevent sunburn but affords little (if any) protection against skin cancer and photo-aging, where UVA1 rays play the major role. Lack of efficacy is compounded by the risk of serious and often permanent adverse effects, due to hormone disruption and carcinogenicity. 

Alternatively, you can choose a balanced sunscreen with insoluble particle type filters with  a MW greater than 500 Daltons.  This prevents entry into the skin as the filter remains within the outer dead layer of skin. A short list of UV Filters meet this criteria: zinc oxide, titanium dioxide, encapsulated octinoxate, Mexoryl SX™, Tinosorb S™, Tinosorb M™, Parsol SLX™, iscotrizinol, octyl triazone, and bisdisulizole disodium.  Only the first 3 are readily available in North America. Often formulas with a good filter are ruined by use of a soluble filter. These particles give more UVA1 protection with balanced UVB/UVA or better protection, and have no possible adverse effects. A balanced sunscreen can lower your melanoma and non- melanoma skin cancer risk and is the best anti-aging measure.

It defies any sensible logic that a parent or expectant mother would select soluble filters if they knew that they attain blood levels and reach the fetus. It is perplexing to me that many physicians continue to recommend their use. Even industry and regulators cannot deny that they attain blood levels. They use the absurd defence that only a small amount is absorbed. No comfort for a small child or unborn fetus. They also ignore the critical fact that these organic compounds are fat soluble and will bioaccumulate in tissue. These filters also come with the instruction to re-apply them several times per day- this can only add to their bioaccumulation in our bodies. 

The Oxybenzone Black List

Benzophenone, otherwise known as oxybenzone, gives context to how the danger exists in our everyday lives. Here is an evidentiary blacklist of reasons why this chemical should be banned from personal care products:

#1: It's Ubiquitous

A 2008 CDC study showed that this chemical is found in 97% of Americans tested, both genders between age 6-70 years (Calafat 2008).  It is still used in 65% of sunscreens in N. America and in over 950 cosmetics, which may explain why it is so pervasive. Women and girls had higher levels of oxybenzone in their bodies than males likely due to differences in use of body care products including sunscreens.

 #2  It's In Our Bodies and Our Children's Bodies

Other studies confirm the CDC report on this insidious and alarming  concern that this  chemical absorbs through the skin in significant amounts. A previous biomonitoring study reported that 96% of 6 to 8 year old girls had detectable amounts of oxybenzone in their urine (Wolff 2007). An earlier study detected oxybenzone in the urine of all 30 adult participants (Ye 2005).

#3 We Absorb More than You Would Think

Studies on human volunteers indicate a wide variation in the level of oxybenzone absorbed into the body, with some individuals absorbing at least 9% of the applied dose, as measured in excretions in urine (Hayden 1997; Janjua 2004; Sarveiya 2004; Gonzalez 2006). Volunteers continued to excrete oxybenzone many days after the last application of the chemical, an indication of its tendency to accumulate in fatty tissues in the body (Gonzalez 2006).

#4 It Increases Absorption Rates of Other Potential EDC's

In addition to its ability to absorb into the body, oxybenzone is also a penetration enhancer, meaning it's a chemical that helps other chemicals penetrate the skin (Pont 2004).

#5 It Has Potential Safety Concerns for Pregnant Women

Mothers with high levels of oxybenzone in their bodies were more likely to give birth to underweight or small for gestational age baby girls (Wolff 2008).

#6 It Could Be Affecting Our Fertility

It was also cited in a NIH report last year as being an important factor in male infertility, according to a study by the National Institutes of Health and the New York state Department of Health’s Wadsworth Center. This study merely underscores what the Endocrine Society, The WHO and The United Nations Environmental Program, have been saying for a decade- that the entire group of about 1000 known hormone disruptors have adverse effects on human reproduction, along with other effects on endocrine function and neural signalling. None of these reports follow through with the deductive analysis that given the patterns of human exposure, it is likely that soluble UV filters represent the most important source of EDC exposure in a developed society. 

#7 It's a Potential Carcinogen 

Sunlight also causes oxybenzone to form free radical chemicals that may be linked to cell damage, according to 2 of 3 studies (Allen 1996; Serpone 2002; Hanson 2006). Hence this generation of reactive oxygen species (ROS) could be carcinogenic to skin- this filter could be involved with causing the cancer it is supposed to prevent.

#8 It has Environmental Effects

The Hawaiians Knew- Sign from 2001 from beach in Maui, Hawaii 

Oxybenzone is contaminating  marine environments – washing off swimmers and in  municipal, residential, and wastewater effluent from marine vessels. A 2015 report (Downs et al) confirms other studies over the past decade that oxybenzone is genotoxic, kills larvae of reproducing coral, and converts the planula from a motile to a sessile state by ossification, due to its action as a skeletal hormone disruptor. Coral reef contamination of oxybenzone in the U.S. Virgin Islands ranged from 75 µg/L to 1.4 mg/L, whereas Hawaiian sites were contaminated between 0.8 and 19.2 µg/L.  Oxybenzone poses a hazard to coral reef conservation and threatens the resiliency of coral reefs to climate change.

#9 It's an Allergen

Oxybenzone and its structural cousin avobenzone are now the leading causes of photocontact allergy (Warshaw 2012). Although this is an infrequent problem, it is just one more reason why this chemical should be banned from personal care products. Consumers and physicians should question its continued use.  In most cosmetics, it’s only used to prevent discolouration in the product. It is still used in over 950 cosmetics and sunscreens.

Are All Sunscreen Actives Created Equally?

All of the organic soluble filters with small molecules (MW in the 250-500 Dalton range or < 1 nm)  should be viewed with the same concern . Many physicians still spread the myth that nanoscale zinc oxide usually 70- 300 nm and titanium dioxide 20-140 nm are so small they should concern us. In the world of sunscreens nano is large – usually  40-600 X larger than the soluble filter group, and nanoscale or micronized particles never penetrate beyond the outer layer of skin. There is a principle in endocrinology – isoform function – whereby chemicals with the same structure likely bind to the same hormone receptor and generally have the same effects. Hence avobenzone and octisalate very likely exert the same toxic effects as oxybenzone and homosalate, known to be hormone disruptors.  Why would anyone defend their  continued use? They enter the blood and brain of any person , including the most vulnerable – the unborn fetus and young children. They give you incomplete protection that could be a factor in rising skin cancer rates, and there is ample evidence that they are hormone disruptors and carcinogens in some cases. Finally, there is the evidence they also affect the health of lower species and destroy our reefs.

The WHO published a 250 page evidence based review entitled “ State of the Science of ENDOCRINE DISRUPTING CHEMICALS 2012 “ representing a broad scientific consensus among the leading experts in related fields. This echoes the warnings in scientific reviews  from The Endocrine Society,  The European Commission and the European Environment Agency. These documents implicate EDCs as a concern to public and wildlife health. In addition, the European Society for Paediatric Endocrinology and the Pediatric Endocrine Society have put forward a consensus statement calling for action regarding endocrine disruptors and their effects. “Of special concern are effects on early development of both humans and wildlife, as these effects are often irreversible and may not become evident until later in life.  The Endocrine Society stated : The evidence for adverse reproductive outcomes (infertility, cancers, malformations) from exposure to endocrine disrupting chemicals is strong, and there is mounting evidence for effects on other endocrine systems, including thyroid, neuroendocrine, obesity and metabolism, and insulin and glucose homeostasis.

The WHO list about 800 possible hormone disruptors, most of whom have never been studied for their possible human effects. Avoiding exposure to the extent you can is important in protecting our children and their children. 

As a follow up, my daughter Sara recently posted a reasoned discussion on why all consumers need to be concerned about hormone disruptors on our company blog (click here to read). She presented a persuasive argument on why a prudent person would try to reduce their exposure to these chemicals that now intersect with our daily lives. She is a new mother, and I take comfort from knowing that our precious new person will have little or no exposure to the permanent, serious, and even transgenerational adverse effects of these chemicals. As parents and grandparents, we will be vigilant and do our utmost to prevent her having any exposure.  She also blogged about sunscreen use in her pregnancy (click here to read).

Clear and Present Dangers of Skin Cancer

Photo Credit: Canadian Skin Cancer Foundation

The average consumer will likely be bored by raw statistics. However, this first post will deal with some essential numbers to illustrate why skin cancer is an important public health problem that affects most Canadians. Later information will focus Canadians and Americans on the clear and present risks from UVB-biased sunscreens and potentially harmful ingredients in personal care products.

Skin cancer is the most common form of human cancer equal to 50% of all cancers in N. America. Over the past 30 years, more patients had skin cancer than the combined total of all other cancers. There are no exact figures as recording of cases is incomplete. Up to 4 million Americans and 120,000 Canadians will develop a skin cancer this year. One in six Canadians and one in five Americans will develop a skin cancer within their lifetime. More alarming, is the rising rate for all skin cancer but particularly the rate for melanoma. There has been an 8X or 800% increase in melanoma in young females and a 4-fold or 400% increase in young males over the past 30 years. Melanoma is the most common form of cancer for young adults 25-29 years old and the second most common form of cancer for young people age 15-25.

Up to 90%of non-melanoma skin cancer (NMSC) and 60% of melanoma is potentially preventable. The Lewin Group report direct and indirect costs for skin cancer care in the USA at 5.5 billion and climbing. The Canadian Partnership Against Cancer Report (February 2010) estimates that we now spend more than $ 600 million annually. In Canada up to 1/4 million cases of skin cancer could cost over a $ billion by 2030.

The use of scarce health care dollars to treat a potentially preventable disease mandates a new direction. There is an effective hierarchy of skin cancer prevention. It starts with educating all people on simple sun safety behavior. Later postings will deal with this in detail. The final step in the hierarchy is the use of effective sunscreens. Australian doctors have shown that daily use of a sunscreen to exposed areas reduced the incidence of melanoma by about 50%. Their sunscreens were older formulations and new innovations with modern sunscreens bring greater promise to further reduce all types of skin cancer.

The potential of balanced sunscreens that give as much UVA protection as UVB is exciting, compared to the limitations and dangers of unbalanced UVB-biased sunscreens, with minimal UVA protection presently dominating the market in N. America. A few UV filters are able to achieve a balanced UVB to UVA protection approaching unity. More about this subject in my next post.

Denis K. Dudley, M.D.