What if endocrine disruptors damage teeth too? It is known that these substances, which can inhibit the action of hormones in the human body, can be responsible for developmental diseases or cancer. They could also weaken teeth, according to the work of Sylvie Babajko, head of research at Inserm.
She and her team are publishing an article in the magazine this Wednesday Environmental Health Perspectives, on the effects of DEHP on tooth enamel in mice. DEHP belongs to the phthalate family. It is used to soften plastics and can be found in food wrap or bottles, but also in blood bags or dialysis and IV machines in hospitals. The researcher explains: publication the importance of studying the effects of endocrine disruptors on teeth.
What does your article published today show?
The originality of our work is to show that teeth are also sensitive to the environment. This is a relatively new concept. We often talk about fertility problems, obesity or cancer related to environmental stress. But we show that the teeth react sensitively to environmental substances even at low doses.
Specifically, you studied the condition of the teeth of mice depending on the DEHP dose to which they were exposed. For what results?
We used two low exposure doses. One, 5 micrograms DEHP/kg/day, is the estimated daily DEHP exposure of a child. The other, 50 micrograms DEHP/kg/day, corresponds to the exposure level of hospital patients on perfusion or dialysis, for example.
Effects are observed in two cases. But the number of animals affected and the severity of the damage are greater at the highest dose. Teeth are dull, discolored, chipped, or chipped. In addition, men are affected more often than women.
What do you deduce from this?
The defects of these teeth are due to a defect in the enamel that is not sufficiently mineralized. It is therefore less hard and more fragile. Our study made it possible to identify the cells attacked by DEHP. These results can be linked to a hypomineralizing pathology of the enamel of the incisors and molars, which today affects 14 to 15% of children worldwide. And their prevalence is increasing. So, exposure to endocrine disruptors like DEHP is believed to contribute. However, the enamel of incisors and molars is formed very early in life, around birth, according to a well-defined chronology. The premolars and canines are less affected. Your enamel will form later. So there is a more critical exposure window.
Are these results consistent with your previous items on this topic?
Yes, we’ve had similar results investigating the effects of another endocrine disruptor, bisphenol A [présent dans les biberons avant son interdiction en 2010, ndlr]. We started this research in 2012-2013 because colleagues studying the effects of endocrine disruptors found their animals had bad teeth.
These kinds of results on endocrine disruptors are always scary, aren’t they?
That’s the whole problem with endocrine disruptors. They can have effects at very low doses, which is why it’s important to conduct research to identify and protect yourself from these molecules. In humans, epidemiological studies show that chronic exposure to mixtures of substances, even at low doses, leads to an increased risk of developing certain pathologies. But research on this topic has yet to be refined to understand the mechanisms involved, and it is difficult. In our case, we don’t have access to the cells that make up the enamel of the teeth because they disappear very quickly in young children when the teeth erupt. However, our experimental approach could make it possible to characterize the exposure to certain substances at the key moment of the child’s first thousand days. [de la fécondation aux deux ans]. If we track the populations with these dental problems over time, we could potentially identify previous other pathologies associated with the same exposures. Our work and that of other teams around the world is designed to provide answers.