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Researchers from the National Institute for Agronomic Research (INRAE) warn of the dangerousness of an additive present in toothpaste, the additive E171. The nanoparticles that compose it pass directly through the oral mucous membranes to then reach the bloodstream.
An additive banned in food but not in toothpaste!
E171 is an additive used in food. It is a white and opacifying dye used until recently in pastries, sweets, sauces or even ice creams. Its use was banned in France from 2020 and then in Europe in 2022 because it contains nanoparticles of titanium dioxide (TiO2) which can cause the appearance of precancerous cells in the colon (among other harmful effects).
But it is still used in toothpastes. This would be a problem for INRAE researchers who discovered that these nanoparticles would be quickly absorbed by the oral mucous membranes and then pass into the blood.
Nanoparticles that damage the DNA of oral cells
INRAE scientists, in collaboration with the LNE (National Metrology and Testing Laboratory in Paris) studied the absorption of E171 by the mucous membranes of the oral cavity. For this, they first analyzed the passage of this additive in the mouths of pigs (whose tissue structure is similar to that of humans) and then studied the effect of its nanoparticles on human oral cells in culture.
The two experiments (in vivo and in vitro) showed that the nanoparticles of the additive were indeed rapidly absorbed. Once absorbed, these nanoparticles damage the DNA of cells because they cause oxidative stress. This has the effect of affecting the survival of growing cells, an effect that could harm the renewal of the mucous membrane that covers the inner lining of the lips and the oral cavity.
When will there be a ban on cosmetics and pharmaceutical products?
This study not only shows that these nanoparticles pass through the oral mucous membranes and then pass into the blood, well before their absorption by the intestine, but also that they can harm cell regeneration within the mouth itself.
The authors of this work emphasize the urgency of taking into account direct exposure of the oral cavity to the food additive E171 when assessing the risks in humans.
When will the additive E171 be banned in cosmetics and pharmaceutical products?