What you and your patients should look out for in sun protection.
Good sun protection reduces the risk of sunburn and skin cancer. However, products that contain toxic ingredients should not be part of these preventive measures.
The American medicine supplier Valisure is known for independently checking the chemical composition of all the products and medicines it sells in its renowned laboratory. In this way, batch tests in recent years have already found carcinogenic substances such as NDMA in several metformin1 and ranitidine compounds2 or DMF in Valsartan3, which exceeded the maximum concentrations permitted according to the Medicines Agency. In such cases, the company also initiates further steps, such as product recalls or the demand for additional measures on the part of the medicines authority.
This has now also happened for a full 43 sunscreen and 8 after-sun care products that contained benzene, an industrial chemical long known to pose serious health risks and, in particular, to cause cancer.4
The FDA recognises the high hazard potential and lists benzene as a Class 1 solvent, which are substances that are generally to be avoided due to unacceptable toxicity (partly genotoxic or harmful to the environment). However, the following wording can be found on this topic: "If the use is unavoidable in order to produce a medicinal product with significant therapeutic progress, then the amount should be limited."
Some batches contained up to three times the conditional FDA concentration limit. The fact is, benzene has no place in sunscreen. Valisure is also calling for less vague regulation from the FDA. A list of all benzene-containing or benzene-free products would go beyond the scope of this article, as over 200 products were tested here alone. ConsumerLab has analysed Valisure's results and offers (behind a login barrier) such an overview, but only of the products selected for this analysis and only with regard to benzene content. The full submission to the FDA, freely accessible here, also contains such tables. The sad front-runner was Neutrogena. Currently, as many different products as possible are being investigated via "crowd sourcing" (consumers can send in their sunscreen for testing free of charge) and will find their way onto the list.
Like other body care products, sunscreen can contain many more substances for which better screening and restrictions would be appropriate. The consolation: Unlike benzene, which represents a contamination that is not visible to the end consumer, these culprits can at least be identified in the list of ingredients.
These include, for example, oxybenzone (benzophenone), homosalate, octinoxate, octocrylene, octyl salicylate or avobenzone. Many of these substances also act as endocrine disruptors, which have been shown to affect reproductive function, oestrogen balance, sperm count and thyroid function.5
Other chemicals may actually increase the risk of developing skin cancer, such as retinyl palmitate. This is a form of vitamin A that accelerates the development of tumours and lesions when exposed to sunlight. Manufacturers sometimes add it to products to slow down skin ageing. However, this is only true if you do not expose yourself to the sun with it.5
Many sunscreens also filter only UVB and not UVA radiation, which penetrates deeper into the skin and plays an important role in the development of malignant melanomas.5,7 But we will address this topic separately in a follow-up article (with figures on different types of skin cancer and the misleading feeling of safety due to high protection values that refer only to protection against UVB).
Products that advertise themselves with "valuable natural ingredients", green leaves or babies on the packaging or downright apothecary-like presentation are not necessarily an exception to this. "Greenwashing" as a marketing tactic is becoming increasingly widespread.
Another development is that manufacturers who have a bad image in this respect buy up established natural brands that already have a good base of trusting customers.6 Often the familiar-looking products then change for the worse, the bought-up brand goes out of business and the time-consuming search for alternatives begins anew.
Another challenge is the constant fluctuation: Substances that have fallen into disrepute disappear, but are not infrequently replaced by new ones that may not trigger scepticism at first glance or whose reputation you first have to look up on one of the many test websites.
Not only does the skin, as our largest organ, represent an essential uptake pathway of toxins into our bodies, but the inflationary use of such ingredients also means, conversely, that overall fewer and fewer truly valuable or useful ingredients are included in our products.
The only real solution is to eliminate harmful chemicals, but we are currently far away from that.
Codecheck is a website and app that translates the chemical gibberish in the small print into a rating that can be grasped at a glance, in the form of a pie chart of green (recommendable), light green (at least harmless), orange (questionable) and red (to be avoided) substances. If you are in a hurry when shopping, you can simply scan the barcode.
In the meantime, I have become accustomed to having an ever-growing "blacklist" of these manufacturers and ingredients at the ready in my mind, but the most annoying thing about it, in my opinion, is that most of these substances should not be contained in the products. Here the power also lies with the consumer.
The best solutions, as far as sun enjoyment is concerned, are zinc oxide-based creams, which have been shown over the years to be safe and effective for protection against UVA and UVB rays8 (and there are definitely some that don't stick or make you look like a ghost). Beware of physical sunblocks with nanoparticles, these are suspected of being toxic to the user but also to marine organisms. Besides, sun hats and sunglasses or clothing are a simple option.5
We wish you a sunny week!
References:
1. Valisure Detects High Levels of NDMA in Metformin. Valisure https://www.valisure.com/blog/valisure-news/valisure-detects-high-levels-of-ndma-in-metformin/ (2020).
2. Valisure Detects NDMA in Ranitidine. Valisure https://www.valisure.com/blog/valisure-news/detection-of-ndma-in-raniditine/ (2019).
3. Valisure Detects High Levels of DMF in Valsartan. Valisure https://www.valisure.com/blog/valisure-news/valisure-detects-high-levels-of-dmf-in-valsartan/ (2019).
4. Valisure Detects Benzene in Sunscreen. Valisure https://www.valisure.com/blog/valisure-news/valisure-detects-benzene-in-sunscreen/ (2021).
5. What You Need to Know About Sunscreen Protection. Mercola.com http://articles.mercola.com/sites/articles/archive/2016/06/08/the-truth-about-sunscreen-protection.aspx.
6. Noch ein Biomarkt schmeißt Naturkosmetik-Marken raus, weil sie von L’Oréal übernommen wurden. Utopia.de https://utopia.de/loreal-logocos-logona-sante-bio-markt-marktladen-102682/ (2018).
7. Planta, M. B. Sunscreen and Melanoma: Is Our Prevention Message Correct? J Am Board Fam Med 24, 735–739 (2011).
8. Zinc Oxide - Physical UVA+UVB sunscreen/sunblock agent. http://www.smartskincare.com/skinprotection/sunblocks/sunblock_zinc-oxide.html.