Every year with the first days of summer they come back: sun protection myths and dangerous misinformation. "Full of toxic substances", "hormonally effective", "natural alternatives", "chemical-free", "pre-tanning", "use raspberry seed oil" etc.

First a few facts:

German Dermatological Society: Around 330,000 people in Germany were newly diagnosed with skin cancer in 2022 (1).

Anyone who doesn't use sunscreen or uses less sunscreen because they 're unsure increases their risk of skin cancer. Yes, the sun is a part of life and has many positive aspects. But its radiation is definitely carcinogenic .

Federal Office for Radiation Protection: UV rays can cause numerous health damages to the skin and eyes - in the worst case, skin cancer (2).

The protection can be so varied that everyone should be able to find something they feel comfortable with. There are many variants to choose from: organic sunscreens, natural cosmetics, organic, sprays, sticks, textiles, etc. As long as the protection is proven according to ISO standards (no DIY or oils!).

Photo: by Nadine E via Unsplash

Five myths:

1. If you are already tanned, you do not need sun protection!

Oh yes! UV-induced tanning (IPF) provides a maximum protection factor of 3-4. Far too little for a long day at the beach in the blazing sun (3).

2. Coconut oil is a great alternative!

Coconut oil is particularly bad with an SPF of around 1 to 3, depending on the study. But other vegetable oils rarely achieve more than 5. Insufficient (4)!

3. In the past, people did not have skin cancer!

In the past, people died at 30 and, as people with light skin, were less likely to be able to sunbathe near the equator. Skin cancer is a sign of aging (but not exclusively!) (5).

4. SPF does not produce vitamin D!

Yes and no, sun protection reduces local vitamin D production, but in everyday life the protection is not perfect enough. In our latitudes, many people have to supplement anyway, because a sufficient amount cannot be produced in winter due to the position of the sun. Tablets, unlike the sun, are not carcinogenic (6).

5. healthy tan...

...does not exist! Any excessive sun exposure adds to the risk of skin cancer (7).

>> Click here for the blog post "Sun protection factor: how long can I stay in the sun?"

Photo: from Trnava University via Unsplash

Why are myths so successful?

How can you reflect on claims about sun protection? Here are a few mechanisms and tools that are often found in populism and science denial in general:

1. Loss aversion

Studies show that we would rather forego a large potential gain than lose a small amount. People are risk averse and like to hold on to the status quo. If damage is caused by inaction , people feel less guilty than if they could actively trigger something negative.

When flipping a coin with a stake of 100 euros, you have to offer an average of 250 euros as a win for subjects to accept the game. Even though the expected value is positive even with a smaller win, they decide against the offer, even though it would rationally be the better choice (8).

That's why we are so susceptible to "warnings". If we are unsure about ingredients, we prefer to avoid them altogether. The fact that doing without them entails a much higher risk, namely skin cancer caused by sun exposure, is ignored at that moment. No sun protection is definitely not the safer alternative!

2. Naturalistic fallacy

One aspect of the naturalistic fallacy is the belief that something that occurs in nature is basically “ good . ” This is opposed to synthetically produced substances such as UV filters (mineral filters are also manufactured industrially and are “chemicals” just like any substance that occurs in nature).

But what about our well-known fly agaric ? Many plants don't want to be eaten. Did you know that 2 teaspoons of a protein produced by bacteria could wipe out the world's population? One of the most potent poisons known: Botox

On the other hand, water can be produced synthetically using hydrogen and oxygen. Of course, it always depends on the exact substance. Neither "natural" nor "synthetic" are generally good or bad. Nature has often been deadly in the history of mankind and (medical) progress has significantly increased our life expectancy. The sun is not harmless just because there would be no life without it.

3. Cherry Picking

Cherry-picking is a technique of science denial . It involves deliberately selecting only data and studies that confirm one's own position . The fact that there is a much larger body of research that shows the opposite is ignored .

For example: If you play “Ludo” long enough, you could possibly win 5 times in a row roll a one. If you look at this moment in isolation , you might come to the conclusion that dice only produce ones. Who would still want to play the game?

It is therefore always a good idea to look at the current study situation to avoid falling for an outlier study. Reviews and meta-studies are useful for getting an overview. Just because there are toxic chemicals in principle, not every product “ containing chemicals ” is toxic.

More myths?

We should also be careful not to spread even seemingly harmless myths. Because myths propagate and multiply. Example:

Organic filters absorb the light, mineral filters reflect it.

Wrong! This view is long outdated. We now know that both types of filters mainly absorb radiation. Mineral filters reflect an additional 5-15% (9).

Why is it important to stop perpetuating this myth? It's pretty descriptive, isn't it? People often jump to conclusions based on incomplete information. They might think that mineral protection doesn't need to be added, or that organic filters are of inferior quality, or something similar.

Sun protection is regulated by several authorities. It is important and right to continue researching to make products even safer for people and the environment. Nevertheless, the current fact is:

Any uncertainty that leads to less sunscreen use does more harm than good to people.

Your Ying

Engineer, Cosmetic Scientist and Founder of Skingineered

Sources:

(1) Professional Association of German Dermatologists, Skin Cancer Month May: Join in – protect yourself!, https://derma.de/presse/uebersicht/detail/hautkrebsmonat-mai-mach-mit-schuetze-dich (Created 06.05.2024)

(2) Federal Office for Radiation Protection, Protection against UV radiation, https://www.bfs.de/DE/themen/opt/uv/schutz/schutz_node.html

(3) Sheehan JM, Potten CS, Young AR. Tanning in human skin types II and III offers modest photoprotection against erythema. Photochem Photobiol. 1998, https://pubmed.ncbi.nlm.nih.gov/9796443/

(4) Ácsová A, Hojerová J, Janotková L, Bendová H, Jedličková L, Hamranová V, Martiniaková S. The real UVB photoprotective efficacy of vegetable oils: in vitro and in vivo studies. Photochem Photobiol Sci. 2021, doi : 10.1007/s43630-020-00009-3

(5) Moan J, Grigalavicius M, Baturaite Z, Dahlback A, Juzeniene A. The relationship between UV exposure and incidence of skin cancer. Photodermatol Photoimmunol Photomed. 2015, doi : 10.1111/phpp.12139

(6) Linos E, Keizer E, Kanzler M, Sainani KL, Lee W, Vittinghoff E, Chren MM, Tang JY. Sun protective behaviors and vitamin D levels in the US population: NHANES 2003-2006. Cancer Causes Control. 2012, doi : 10.1007/s10552-011-9862-0

(7) Barbara A. Gilchrest, Molecular Aspects of Tanning, Journal of investigative dermatology, 2011, doi : 10.1038/skinbio.2011.6

(8) Gesine Heeren, Neural Basis of Loss Aversion, Dissertation, Bonn, Rheinische Friedrich-Wilhelms-University Bonn, 2018

(9) Cole C, Shyr T, Ou-Yang H. Metal oxide sunscreens protect skin by absorption, not by reflection or scattering. Photodermatol Photoimmunol Photomed. 2016, doi : 10.1111/phpp.12214