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.

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.

Kat