The Null Hypothesis.: No. Sunscreen will not give you cancer!

The sun is shining again, summer is here, and that means with some certainty posts will start appearing on social media espousing the benefits of forgoing sunscreen and suncream or alternatively warning that such measures can damage health. That includes irresponsibly warning that sunscreens themselves can cause cancer. And indeed pose more of a cancer risk than the sun itself.

This week brought one such article to my attention. Published in February of 2017 on the site Collective Evolution, a well-spring for awful science reporting, the article 'HOW SUNSCREEN COULD BE CAUSING SKIN CANCER, NOT THE SUN' (1) proposes to show evidence from 'peer-reviewed' studies to prove sunscreens could be doing more harm than good. Let's examine the veracity of the claims made in the article.

The piece begins with a troubling picture of a severely sunburned back. It's an odd image choice to head an article that suggests avoiding sunscreen and promotes the natural benefits of the sun. This lady's back clearly wouldn't have been so badly damaged had she avoided sun-exposure or used sunscreen!

Ouch! An odd image to choose to front your article about avoiding suncream!

The first paragraph strongly highlights the severe lack of knowledge the author is going to display and the propensity to drop scientific claims without citing supportive literature. It begins:

"Yet, while we do indeed need protection to prevent sunburns, blocking out the sun entirely is not ideal. Rich in vitamin D, it offers a number of other health benefits, including, oddly enough, cancer prevention."

Firstly, a minor gripe. Sunlight is not "rich in vitamin D" as the article laughably suggests. There are no chemicals in sunlight. The connection between sunlight and vitamin D as ultraviolet B light on the skin triggers its production in the body. Even articles such as the one provided by the NHS which I read (3) whilst advising on the benefits of vitamin D also advise the use of at least a spf15 sunscreen and exposure to the sun for short periods only.

There is some evidence that vitamin D deficiency is linked to some cancers but it's an extremely relationship to quantify, as an estimated 40% of the population in the US and UK are vitamin D deficient (4). Studies conducted thus far, like the one I've referenced, have struggled from the fact that they are simply observational, with subjects continuing with established cancer-causing behaviours such as smoking, the eating of fatty foods and drinking alcohol... and exposure to the sun.

The Classic Bait and Switch

"We’ve been made to fear the sun, and, as a result, adults and children are choosing to drench themselves in a bath of toxic, hormone-disrupting chemicals."

The claim that sunscreens contain "toxic, hormone-disrupting chemicals" is unsupported by any evidence in any form. This claim is subject to an interesting bait and switch which underpins the deceptive nature of the article. Whilst not supporting this claim, the author does provide support for the claim that chemicals in sunscreens have been found to penetrate the skin and enter the body to some extent.

"Multiple studies from across the world have examined sunscreen in particular, evaluating its ingredients and how it penetrates and absorbs into the skin after application... Results demonstrated a significant penetration of all sunscreen agents into the skin, meaning all of these chemicals are entering multiple tissues within the body,"

Checking the study cited (5) in support of this reveals that chemicals from sunscreens do indeed penetrate the skin, and research has been suggested to limit his absorption. But what the study liked does not state is that these chemicals are responsible for the type of tissue damage associated with causing cancers. Further studies have established that despite these chemicals leaching across the skin, there is no sign of associated tissue damage (6).

Another thing that should be noted about the study cited in support of the claim above is that it's badly dated. The study cited is now 14 years old and thus won't take into account changes in sunscreen ingredients in this intervening time. Later research involving sunscreens has shown no skin penetration of constituent nanoparticles (7). The article doesn't mention any of these more recent findings.

So as many articles of this type do, we have seen two distinct claims made:

1. Chemicals in sunscreens are toxic and harmful, potentially cancer-causing.

2. Chemicals in sunscreens penetrate the skin.

The author provides evidence, albeit extremely flawed, of the second claim and hopes the reader will not notice (or bother to check) that the first claim is also supported. Classic bait and switch.

Poisoning the Well; Corporations are evil!

Another common theme with articles of this nature are the claims that big-businesses are corrupt and will quite willingly harm their customers and clients. In this article that extends to not trusting the results of studies that have been funded by corporate bodies.

"The science given to us by the corporations who profit from the sale of sunscreen says no, but I think by now we have established how trustworthy such corporately-funded ‘science’ is."

How has this been established exactly? I'm no fan of big business and I too am suspicious of results from corporate-funded studies. That's why it's important to go over these studies with a fine-tooth comb. The source of funding shouldn't immediately invalidate research. To say otherwise is simply throwing the baby out with the bath water.

Of course, the author of this article is choosy in how they apply their suspicion of corporations. If they weren't they may well have questioned the veracity of the study they cited to support their earlier claim. Hill Top Research Inc, who part-funded the study, is a company which works closely with the pharmaceutical, food and cosmetics industry. Exactly the kind of company that Collective Evolution would likely warn its readership not to trust!

The article then makes a specific claim about company Johnson & Johnson intentionally marketing a baby powder it allegedly knew to be "cancer-causing"

"It wasn’t long ago that Johnson & Johnson, for example, was found guilty of knowingly putting a cancer-causing baby powder on the market. You can read more about that here."

The link leads to another article on Collective Evolution written by the same author as this one (8). The article is well-worth exploring in more detail, but in short, it documents a successful legal challenge against Johnson and Johnson in regards to a case of ovarian cancer which was allegedly brought about by use of baby powder. The decision was made by a judge and does not reflect the current scientific understanding of baby powder ingredients as being carcinogenic. There is no strong evidence that baby powders lead to ovarian cancer, so to suggest that a company 'knew' that this was the case is completely untrue. Scientific consensus is not reached in courtrooms. Judges are not scientists, opinion is not evidence and trials are not clinical trials. Whilst the author mentions this successful case, they omit the cases against Johnson & Johnson that have been dismissed or overturned (9).

And in any case... even if Johnson & Johnson are as guilty as the author suggests, what does this tell us about their sunscreens? What does it tell us about other company's sunscreens?

If you said 'nothing' give yourself a biscuit.

A complete absence of self-awareness

Prepare yourself for perhaps the most ironic statement ever committed to screen or page, so completely lacking in self-awareness that you yourself may lose your own self-identity after reading it:

"(Referencing a Huffington Post article) Sarah Kallies shares how exhausted she feels trying to navigate today’s world and do the best for her children when everything, everywhere, seems to be killing us. For every purchase she makes for her children, there is science telling her it’s great on the one hand and toxic on the other, and so she highlights how confusing the consumer marketplace has become. We are dished a wealth of information that differs from source to source, on a variety of different topics, making it difficult to make even the simplest of choices without second-guessing ourselves."

But it's this author and this site creating that confusion in this case. By performing a completely disingenuous bait and switch, this piece indicates that sunscreens are unsafe, in complete opposition to the scientific consensus on the same. Articles like this are creating the confusion. It's not science to blame here it's the misrepresentation of science that is the enemy of the general public. To imply that you are adding clarity to the issue after purposefully obscuring the issue is absolutely disgusting.

The author again reiterates:

"Yet we know the various chemicals found within sunscreens are toxic, and we know that our skin absorbs whatever we put onto it."

A statement that is in complete denial of the fact that the author has made no effort to prove the most relevant element claim. They haven't cited a single study that shows the toxicity of sunscreen constituents. But wait... the author ends the article by discussing specific compounds. Could these the scary toxic chemicals they have been discussing in the article.

Scary Chemicals!

As usual with an article of this nature, it eventually descends into a demonstration of chemophobia.

Are any of the compounds the article mentions as dangerous as it implies:

Oxybenzone.

Collective Evolution says:

"This could in fact be the most troublesome ingredient found in the majority of popular sunscreens. Used because it effectively absorbs ultraviolet light, it’s also believed to cause hormone disruption and cell damage, which could promote cancer... one study done by the Department of Clinical and Experimental Endocrinology at the University of Gottingen in Germany observed regulatory effects on receptor expression for oxybenzone that indicate endocrine (hormone) disruption."

The article doesn't link to the study, so I had to search for it, thus I can only guess that the study referred to is this one (10). The first thing that is abundantly clear is that the study shows the effects of oxybenzone-2 and oxybenzone-3 on ovaries removed from rats. We can't extrapolate this result to humans for a variety of reasons.

Firstly rats have a different morphology to humans, even though there are similarities we cannot assume that a compound that has one effect in rats will have the same effects in humans. Secondly, the compound, in this case, is delivered directly to an organ. It isn't leeched through the skin and diluted in the blood. as such, the dosage delivered is much higher than that expected to be received via sunscreen.

None of this supports the declaration of oxybenzone as 'toxic' in regards to humans. The study doesn't conclusively demonstrate oxybenzone is toxic to rats even!

Retinyl Palmitate (Vitamin A Palmitate)

Again with the above compound, the linked 'study' involves animal cohorts and as such should be treated cautiously when extrapolated to humans. The link isn't a study at all but rather a governmental executive report requesting further investigations and human trials.

With regards to the idea that Retinyl Palmitate causes tumours in conjunction with UV radiation, Steven Q Wang, a dermatological surgeon highlighted the problem with studies in this area (11): "It is important to note that the mice in the NTP study are highly susceptible to the effects of UV radiation and can develop skin cancer or other skin abnormalities within weeks of UV exposure, even in the absence of retinyl palmitate," said Dr. Wang. "That is why extreme caution is needed when extrapolating these animal study results to humans."

The hypocrisy at the heart of this article and alternative medicine as a whole

The only other source offered in support of the toxicity of Retinyl Palmitate is one Dr Joseph Mercola, who may be familiar to readers of the Null Hypothesis.

The link leads, not to a study of any kind, but to Mercola's website where the dangers of sunscreens are reiterated with no evidence what-so-ever (12). At the bottom of this linked page, there is a striking example of the hypocrisy that is inherent in this report and others that support alternative medicine. After a long spiel about the dangers of sunscreen, Mercola's website attempts to sell visitors a vitamin D testing kit for $65 (13).

So the author of this post warns us not to trust companies that simply want our money Their profit-driven attitude implies they don't care about our health. But the sources they trust don't offer their services for free do they? It's somehow acceptable when Mercola wants to make a profit, but other companies are monsters, driven by the almighty dollar.

Don't take health advice from such blatant fucking hypocrites. Exposure to the sun is a well-established cause of cancer. Compounds in sunscreens are not.