Could the cosmetic products we use be harming our health in any way? A while back, Henry neatly debunked the persistent myth that deodorants are linked to breast cancer. Today, another study comes out that turns the spotlight on another group of products – moisturising creams.
The study found that common moisturising creams can increase the risk of skin cancer in mice that had already experienced high doses of ultraviolet (UV) radiation, mimicking the effect of heavy sun exposure. Let’s take a closer look at the results.
What they found
The study, published in the Journal of Investigative Dermatology, comes from a team of American researchers led by Yao-Ping Lu, who practically stumbled across their results by accident. They were actually following up on an earlier study, where they found that applying caffeine to the skin of mice could reduce their chances of developing skin cancer, after being exposed to UV radiation.
Obviously, smearing coffee beans over your face isn’t ideal, so the team wanted to develop a ‘caffeine cream’ based on every-day skin moisturisers. But first, they thought it’d be best to be sure that the moisturisers themselves were completely safe. And to their surprise, they weren’t.
First, they shone heavy doses of UV radiation (of the type that leads to sunburn and skin cancer) on the mice twice a week for 20 weeks. After that, some of the mice were left alone, and others were treated with Dermabase moisturiser once a day, 5 times a week for 17 weeks.
They found that the moisturised mice were twice as likely to develop non-melanoma skin cancers (NSMCs) as their untreated peers, and to develop them in greater numbers. Half of the treated mice developed NMSCs, compared to one in four of the untreated ones. Other types of moisturiser, including Dermovan, Eucerin and Vanicream also had the same effect.
The team also tried treating the UV-exposed mice with water alone to see if their increased risk of cancer was just an effect of placing anything on their skin. It wasn’t – the water didn’t do anything.
A word of caution
So does this mean that moisturisers cause cancer? Not quite – but it does highlight some questions that need to be addressed with more research.
For a start, non-melanoma skin cancer is more common in men, even though women are more likely to use moisturisers. The rates of NMSC in the UK population have effectively provided us with a ‘natural experiment’, which shows that even if moisturisers can boost the effects of UV damage, they don’t play a major role in this type of skin cancer.
It’s also important to note that the study was done in mice and, for the moment, we have no idea if the same thing would happen to humans. Mouse skin is very different to human skin, and we’re not just talking about the fur; mouse hide is thinner than ours and absorbs chemicals more readily. So making any assumptions about the effects of moisturisers on human skin is extremely premature.
Also, these mice already had a naturally high risk of skin cancer, and they were bombarded with so much UV radiation that even a quarter of the unmoisturised mice developed NMSC. In fact, six in seven of them developed some sort of skin tumour.
So it’s unlikely that the moisturisers directly cause cancer. It’s much more likely that they’re just aggravating the effects of UV radiation, which we know can cause skin cancer by damaging the DNA of skin cells.
In fact, the authors of the paper speculate that these products could have worsened the effects of existing DNA damage by causing inflammation, and encouraging the damaged cells to start dividing.
Playing it safe
So if (and it’s a big if) moisturisers and UV radiation interact in the same way on human skin, there is a way of preventing this from happening – avoid heavy exposures to UV radiation. Indeed, our SunSmart campaign already advises people to do this, while enjoying the sun sensibly..
In the meantime, the study raises a few questions that are worth answering:
- This is the first study to look at the combined effects of moisturiser use and heavy UV exposure. The results are interesting, and need to be repeated in other experiments.
- We need to see if the results apply to human skin.
- NMSC is very common but the vast majority are effectively removed through surgery. We need to see if these products could affect the development of melanoma, a rarer but more dangerous type of skin cancer.
- The researchers looked at the ingredient lists of the moisturisers and identified two ingredients that they thought may have been responsible for the problems: sodium lauryl sulphate and mineral oil. Without these ingredients, the moisturisers no longer had any effect on the mice. These ingredients are commonly used in cosmetic products, so it’s important to understand exactly how these chemicals interacted with heavy UV radiation exposure to affect the risk of skin cancer.
It’s far too early to come to any conclusions about these chemicals, or to worry if you use products that contain them.
If you are concerned about NMSC, the best thing to do is to stay safe in the sun, and avoid the type of heavy exposures that lead to reddening or burning. If you follow this advice, there is no reason to believe that these products would do you any harm.
selene March 22, 2010
thanks for the information. these articles are very clear, i was staring to get really woried about moisturising creams and deodorants, ive heard a lot about the harming of aluminum, it is a relief to know there is no proven link between cancer and these chemicals. i am not gonna stop using this chemicals, but im going to try use use them less often
shelley kramer February 28, 2009
Obviously the people responding to the information on my website, have no clue about the facts what they are saying. I have been researching this area of cancer for over 25 years. I research the research and do not put up anything on my website that is not factual. Read Dr. Samuel Epstein’s books and website (he is from the UK) http://www.preventcancer.com. Read http://www.safecosmetics.org, read, http://www.ewg.org. These are third party organizations that tell about the dangers of these chemicals in daily used products. It is up to us as consumers to know this information. I am only the messenger and a cancer survivor and only want the public to be able to make healthy choices, once they know the information. I am not out to “scare people” as stated above. Again I guess this person did not do their own research to find out the truth of the matter. The EU is much stricter on chemicals used in products than the US, and long ago stated that cocoamide DEA, diethanolamine, TEA, triethanolamine, sls, mineral oil, petrolatum, propylene glycol (from petrol) are harmful ingredients.
uvb light February 20, 2009
I thing the most imporatand and prominent cause of skin cancer is uvb light from sun.
blake December 8, 2008
because it will help find cancer before we know its there and help cure cancer
Raffaella December 3, 2008
In the same way as it dissolves the grease on car engines, sodium lauryl sulfate also dissolves the oils on your skin, which can cause a drying effect. It is also well documented that it denatures skin proteins, which causes not only irritation, but also allows environmental contaminants easier access to the lower, sensitive layers of the skin.
Perhaps most worryingly, SLS is also absorbed into the body from skin application. Once it has been absorbed, one of the main effects of sodium lauryl sulfate is to mimic the activity of the hormone Oestrogen. This has many health implications and may be responsible for a variety of health problems from PMS and Menopausal symptoms to dropping male fertility and increasing female cancers such as breast cancer, where oestrogen levels are known to be involved.
Kat Arney August 27, 2008
Thanks for the comments – sorry it’s taken us a while to get to this one.
The safety of cosmetics is obviously an important area of concern for many people, and in the EU there are strict regulations about what can and can’t be included in them. Cosmetics ingredients are also tested for potential cancer-causing effects.
With regard to Shelley’s comment, there is little solid scientific evidence to support the claims that she is making.
We are surrounded by chemicals – both natural and unnatural – that do us harm and good. Water is a chemical, oxygen is a chemical, the food we eat is full of naturally occurring chemicals. Looking at the example of mineral oil, it has been shown by IARC (the International Agency for Research on Cancer) that there is sufficient scientific evidence that untreated and mildly treated mineral oils can cause cancer in humans, yet there is inadequate evidence that highly-treated oils (the kind mainly used in cosmetics) can cause cancer. http://www.inchem.org/documents/iarc/suppl7/mineraloils.html
Statements like this “Sodium lauryl sulfate could be from the contaminated coconut ingredients and combines with other chemicals, like propylene glycol, for form nitrosamines, cancer causing ingredients” are simply not supported by scientific evidence, and there’s nothing to show that these chemicals (in the context of cosmetic usage) pose any kind of significant cancer risk to humans.
Finally, it’s important to focus on the cancer risks that are supported by large, consistent scientific studies. We know from plenty of solid research that excessive exposure to UV radiation, either from sunlight or sunbeds, is the major cause of both melanoma and non-melanoma skin cancers. As Ed pointed out in his post, the main “take home message’ from this story should be that exposure to excessive UV is the real baddie here, not necessarily the moisturiser.
Rather than focusing on unsupported inferences and conjecture about what may or may not be present in cosmetics – which are regulated and tested – it’s best to take care of your skin in the sun, and avoid sunburn and sunbeds.
anon August 22, 2008
please delete the above comment- it has no factual basis and may confuse cancer sufferers and individuals with no scientific background.
Shellley Kramer August 17, 2008
Finally the truth is coming out although they left out some of the most important parts. Mineral Oil is from gasoline, no question about it, which is a known carcinogen, and reported on the governments Dept of Toxicology Report on Carcinogens. Mineral oil and cocoamide DEA (which was on NBC news not ABC back in 1998) has been banned from European products for many years, as is cocoamide DEA, which is from the coconut plant, However, they are usually 99% sprayed with pesticides and contain dioxans, which are carcinogens. The public has to wake up to the facts, truths and avoid many of the chemicals that are in the daily used personal care and beauty cosmetics. Read Campaign for Safe Cosmetics, Environmental Working Group. The companies that provided the products make so much money off consumers, and because there are no new laws, they produce what they want. Do they really care about humans or corporate profit? Sodium lauryl sulfate could be from the contaminated coconut ingredients and combines with other chemicals, like propylene glycol, for form nitrosamines, cancer causing ingredients. The Public Deserves the right to know what they are putting in and on their bodies and know that safe alternatives are available. I am a cancer survivor myself, from basal, and squamous cell tumors removed from my lip, eyelid, nose. I have been studying the whys of cancer for over 26 years. Finally the truth is being told about the chemicals in our products. If there is any doubt a chemical could be harmfull, why would anyone want to use it when alternatives are available? http://www.healthy-communications.com
[Edited by Kat to add – Cancer Research UK is not responsible for the content of external websites. We will be responding to this comment shortly]