Have you seen this article by Paul Fassa that has been all over Facebook about skin cancer and sunscreen?

When you see things like this do you ever become curious and wonder if its true?  In this case, I couldn’t resist. Is there really some new piece of research out there that turns everything I know about skin cancer and sunscreen on its head? In my world, this would be a big deal.

So I took a look at the article and the actual research article it purports to cite: joim12251.  The study involved following about 30,000 Swedish women, recruited from 1990-1992.  When first enrolled in the study, a variety of demographic details were collected, including answers to these questions about sunbathing:

1. How often do you sunbathe during the summertime? never, 1-14 times, 15-30 times, >30 times
2. Do you sunbathe during the winter, such as on holiday in the mountains? no, 1-3 days, 4-10 days, >10 days
3. Do you use tanning beds? never, 1-3 times per year, 4-10 times, >10 times per year
4. Do you go abroad on holiday to swim and sunbathe? never, once per 1-2 years, once per year, 2 or more times per year

Then, they looked at deaths in this group.  Of the 30,000 women, there were 1721 who answered no to all 4 questions about sunbathing.  When compared to the rest of the women who answered yes to at least one of the other questions, the women who answered no had a higher death rate (they were also twice as likely to have <9 years of education, have low disposable income, have other comorbidities, and have a BMI greater than 30, although somehow the study authors were able to dismiss these differences as insignificant).  From this, the authors conclude that their is observational evidence that avoiding the sun is a risk factor for death.  From this, they suggest that following very restrictive sun exposure habits in a country with little sun (Sweden) may be harmful to women’s health.

Somehow, Paul Fassa took this to mean that sunscreen causes cancer, you shouldn’t use it, and that protecting yourself from the sun is some giant myth that scientists just blew the lid off.

A Letter to Paul Fassa

Dear Paul Fassa,

Your article is factually wrong nearly from start to end and the conclusions you make are ridiculous.  Here are a few highlights:

Paul Fassa’s world:

That’s because overall sun avoidance combined with wearing sunscreen effectively blocks the body’s ability to produce vitamin D3 from the sun’s UVB rays, which is by far the best form of vitamin D.

Reality

Vitamin D is Vitamin D.  Vitamin D synthesized in the skin following exposure to ultraviolet radiation is the exact same as Vitamin D from a pill.  Our body does not care at all where it comes from.  I would argue that the best form of Vitamin D is one that you can get without exposing yourself to a carcinogen.  Mr Fassa, if I told you that the most awesome form of Vitamin D in the world came in arsenic coated pills or involved walking into nuclear reactor, would you take that instead of the perfectly safe form in fish or in bottles at any pharmacy?

Moreover, there have been studies showing that humans deficient in Vitamin D were unable to correct their deficiency with sun exposure, and other studies showing that taking a Vitamin D supplement is by far the most reliable way to ensure adequate Vitamin D levels.

Paul Fassa’s world:

Additionally, vitamin D protects the body from diseases like multiple sclerosis, rickets (in the young), tuberculosis, inflammatory bowel disease, type 1 diabetes, inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus and Sjogren’s syndrome.

Reality

These conclusions are dramatically overstated.  There is ok (but actually not great) evidence that Vitamin D protects against osteoporosis and rickets, but the claims you make here are based on observational studies that have been challenging to reproduce.  Conclusive data does not yet exist.  To make these claims, we need randomized controlled trials that show that Vitamin D supplementation reduces the incidence of these conditions.  Until then, this remains a big maybe and presenting it as the truth is irresponsible.

Paul Fassa’s world:

The link between melanoma and sun exposure (dermatology’s dogma) is unproven.There’s no conclusive evidence that sunburns lead to cancer.There is no real proof that sunscreens protect against melanoma.There’s no proof that increased exposure to the sun increases the risk of melanoma.

Reality

The connections between ultraviolet radiation and melanoma are well established based on a multitude of observational studies conducted in humans and well grounded in experimental animal systems.  Simply searching Pubmed for “ultraviolet melanoma risk” pulls up 1087 articles.  Data showing a connection between sun exposure and melanoma dates back over 60 years.  Every now and again there are studies that fail to show a link, but the overwhelming majority, done in countries all over the world, come to the same basic conclusion – sun exposure increases your risk of melanoma.  Most of the current research in this area has moved beyond that basic, well accepted point, and instead focuses on the nuances of patterns of sun exposure.

As for evidence that sunscreen protects against melanoma just a few years ago, a randomized controlled trial performed in Australia showed that regular use of sunscreen cuts the risk of melanoma in half.  The article is not that hard to find.  Sunscreens have also been shown to substantially decrease the risk of squamous cell carcinomas in another randomized controlled trial.  The beautiful thing about randomized controlled trials is that they give us very good insight into the effects in the real world if patients are divided into equal groups and then told to do something.  In these trials, using sunscreen led to decreased cancer.

Paul Fassa’s world:

Elizabeth Plourde, PhD, is a California-based scientist who authored the book Sunscreens – Biohazard: Treat as Hazardous Waste, which extensively documents the serious life-threatening dangers of sunscreens not only to people but to the environment as well.

Dr. Plourde provides proof that malignant melanoma and all other skin cancers increased significantly with ubiquitous sunscreen use over a 30-year period. She emphasizes that many sunscreens contain chemicals that are known carcinogens and endocrine-disrupting chemicals (EDC).

Environmentally, she notes: “In areas where there has been much exposure to ED [endocrine disrupting] chemicals, coral and other sea populations have died off and the prevalence of dual-sexed fish has risen.”

Reality

These arguments remain quite theoretical and should be taken with a grain of salt.  As an illustration, melanoma and skin cancers have increased in parallel with the number of households who own personal computers, the number of televisions in the house, and video game sales.  Clearly, staying inside and using these types of electronic devices is a major skin cancer risk along with ubiquitous sunscreen use!  If only proof of causation were so simple.

As for the safety of sunscreens, I realize that there are people out there who just will never trust the findings of all the world’s regulatory agencies that have dispelled the concerns over endocrine-disrupting chemicals in sunscreens and have found them to be completely safe over and over again.  So, let’s move past that.  There are over 1500 sunscreens on the market.  It is not difficult at all to find ones that do not have oxybenzone or nanoparticles, the things that Dr. Plourde is concerned about.  The Environmental Working Group has a very comprehensive database on sunscreens, making the chore super simple.  Suggesting that certain ingredients in sunscreens could be toxic is merely a reason to be choosy about the type of sunscreen that you use.

Summary

Everyone is entitled to an opinion, but misrepresenting science and pitching it as the truth makes you a liar.

I have two opinions here:

1. It is reasonable to be concerned about Vitamin D levels and to be concerned about the ingredients in products you use on your skin.  However, regular sunscreen usage in conjunction with other sun protection habits is the only factor in skin cancer prevention within our control.  Therefore, I recommend the regular practice of sun protective habits, daily supplementation with Vitamin D, and consideration of avoiding certain sunscreen ingredients.
2. Mr. Fassa, you are why patients can’t trust what they read on the internet. The ill-informed advice you give will cause harm to people, which makes spreading your opinion malicious.

Sincerely,

Arlo Miller, MD, PhD