Would antiperspirant deodorants promote breast cancer? The question has been debated for several years in the scientific community. A new study, published in the journal International Journal of Molecular Sciences in September, comes to bring elements pointing out the probable harmfulness of aluminum salts, present in many deodorants.
A group of researchers from the Fondation des Grangettes, the Hirslanden Oncology and Hematology Center at the Clinique des Grangettes, and the University of Oxford, led by the Swiss André-Pascal Sappino and Stefano Mandriota, exhibited in hamster cells – including mammary gland cells – to aluminum salts in vitro. Their results show that, not only does the metal enter cells, but also quickly causes genomic instability in these cells.
“The research carried out makes it possible to show that aluminum alters the DNA of cells by methods equivalent to those of recognized carcinogenic substances and thus confirms its carcinogenic potential”, affirms the Fondation des Grangettes in his press release on the subject.
Difficult to transpose the results to humans
Biologist Stefano Mandriota and oncologist André-Pascal Sappino had already shown in 2012 that human breast cells cultured and exposed to aluminum in vitro underwent a genetic modification. In 2016, their studies showed that mouse mammary gland cells cultured in the presence of aluminum concentrations at a level comparable to that found in the human breast caused, when injected into mice, very aggressive metastatic tumors. Their latest study helps explain the mechanism by which aluminum enters cells and confirms that genetic modification can be the cause of genomic instability. However, the latter is typical of that found in almost all human tumors.
For researchers, the link between the use of antiperspirant deodorants and the increase in the number of breast cancers observed over the past fifty years must be taken seriously. “More than 80% of tumors occur in the outer part of the gland, the one near the armpit”, explained André-Pascal Sappino on France Inter Tuesday 12 October.
However, explains Franceinfo, the researchers themselves admit that extrapolating the results is not straightforward. To establish a true causal link between the use of deodorants containing aluminum salts and the appearance of breast cancer in humans, it would be necessary to conduct large long-term studies including groups of users. of these products. The results would not be known for several years.
Precautionary principle
In the meantime, the results of Swiss researchers are debating. The Scientific Committee for Consumer Safety (CSSC), an advisory committee of the European Union, has estimated in a report published in March 2020 that deodorants did not present a health hazard if their aluminum concentration was less than 10.60% for sprays, and 6.25% for others. These figures are higher than the concentrations observed in the products on the market. The CSSC also claimed that “Systemic exposure to aluminum via daily cosmetic applications does not add significantly to the body burden of aluminum from other sources.”
In 2011, the National Agency for the Safety of Medicines and Health Products (ANSM) concluded that there was no evidence of the link between exposure to aluminum through the skin and the appearance of cancer. The ANSM, however, recommended to limit the aluminum concentration in cosmetics at 0.6%, and not to use products containing aluminum just after shaving or on damaged skin, as absorption is stronger in these cases.
But, for the Fondation des Grangettes, the latest studies carried out by Stefano Mandriota and André-Pascal Sappino “ draw for [l’aluminium], a path similar to that already seen for carcinogenic agents now proven such as tobacco or asbestos ”. These scientists call on the authorities to restrict, as a precaution, the use of aluminum by the cosmetics industry.