Certain antibacterial products containing triclosan that are found everywhere in everyday life are associated with a marked increase in the proliferation of liver cells, the appearance of fibrosis and strong oxidative stress. Without being directly carcinogenic at current doses of use, these antibacterial products nevertheless promote the appearance of liver cancer.
Triclosan is a phenolic compound with antibacterial, antifungal and antiviral properties. Marketed in 1972 as an antibacterial agent for washing hands during surgical operations, its use has gradually expanded to a wide range of common hygiene products, whether liquid soaps, cosmetics, shampoos, toothpastes , deodorants, mouthwash or other so-called “antibacterial” or “anti-odour” products.
Although triclosan is considered safe at the amounts present in these products, daily exposure to this molecule has greatly increased over the past 20 years.
There must be around 1600 products that contain triclosan and that more than 80% of the population is exposed to this molecule, as shown by its presence in standard urine tests.
The omnipresence of this molecule in our daily lives and its increasingly significant accumulation in the environment, in particular in aquatic ecosystems, therefore raises several questions about its longer-term impact on health.
Fibrosis and liver cancer
A team of Californian scientists recently published the results of a study on the impact of prolonged exposure to triclosan on liver function. They first observed that repeated administration of the molecule to mice over a period of 8 months (the equivalent of approximately 20 human years) was associated with a marked increase in the proliferation of liver cells, the appearance of fibrosis as well as strong oxidative stress.
These results are of concern, as they suggest that the presence of triclosan could promote the creation of an inflammatory microenvironment conducive to the progression of cancer cells.
In fact, animals treated with triclosan become much more likely to develop liver cancer in response to a carcinogenic molecule (80% incidence versus 25% for the carcinogen alone) and these tumors are much more numerous and larger.
Therefore, without being a carcinogen as such, triclosan could create favorable conditions for the development of microscopic hepatic tumours, for example those induced by substances in the environment or in our diet (benzopyrene and heterocyclic amines ).
It is always difficult to extrapolate toxicology data acquired in animals to humans, but these observations nevertheless suggest that it may be appropriate to re-evaluate the large-scale use of products containing triclosan.
Antibacterial soap does no better than regular soap
Caution in the face of antibacterial products is all the more justified as these products are not necessarily superior to conventional products. For example, studies to date indicate that washing hands with “antibacterial” soap does not kill more bacteria than regular soap: it’s not the soap that counts, it’s how you wash your hands. scrub! For perfect hygiene, the hands must be soaped for at least 20 seconds, making sure to wash all the places in contact with surfaces in our environment, including between the fingers and under the nails.
Choose hydro-alcoholic solutions instead
When water is not available, a hydro-alcoholic solution containing at least 60% alcohol should be preferred, whether in liquid, gel or foam form. These solutions are very practical when you are on the move, but it must be remembered that they are ineffective if the hands are very dirty (food, soil). Nothing better than rubbing them with a good old soap!
Yueh MF et al. The commonly used antimicrobial additive triclosan is a liver tumor promoter. Proc Natl Acad Sci USA, 111:17200-5.