HomeSafetyNew study on the risks of titanium dioxide present in toothpastes and...

New study on the risks of titanium dioxide present in toothpastes and medicines

Titanium dioxide (E 171), a dangerous whitening and matting additive, is also absorbed through the mucous membranes of the oral cavity. This is demonstrated by a French study (Vignard et al., 2023) published on Nanotoxicology, which shows the dangers of toothpastes, drugs and cosmetics containing this substance. (1)

The danger of the additive E 171

Authorized in 1969 As a food additive, E 171 has been widely used in candy, chewing gum, ice cream, soft drinks, sauces, as well as in almost all food supplements. (2)

The scientific community has repeatedly indicated that the nanoparticles of which the titanium dioxide additive is composed, once ingested, accumulate in the liver and spleen after their absorption from the intestine, but also in the placenta, until they contaminate the fetus. Experiments in animal models have also shown that they can cause precancerous cells to appear in the colon.

In the light of so much evidence, the use of titanium dioxide in food and supplements has been banned in France since 2020 and in the whole European Union only in 2022. (3,4) However, this dangerous additive remains authorized today in cosmetics, toothpastes and drugs.

Titanium dioxide, the new study

Research so far he had demonstrated the dangers of E 171 following the intestinal absorption of the molecule in experiments with rodents, whose keratinized mouths do not absorb the nanoparticles.

The new study instead he concentrated on the absorption by the mucous membranes of the oral cavity of pigs, whose tissue is very close to the human one, from a histological point of view.

French scientists of INRAE ​​(Institut national de recherche pour l'agriculture, l'alimentation et l'environnement) in collaboration with the LNE laboratory (National Metrology and Testing Laboratory, Paris) have thus studied the risk in vivo e vitro:

– first they evaluated the passage of E 171 nanoparticles through the oral mucosa of pigs,

– then they observed the effect of the nanoparticles on cultured human oral cells vitro.

The test results

In tests, in vivo e vitro, titanium dioxide nanoparticles have

– quickly crossed the oral mucosa to reach the bloodstream,

– damaged the DNA of the epithelial cells that cover the hollow organs (the inside of the mouth, the wall of the intestine, etc.) and act as a biological barrier against what we ingest.

The results of the study therefore indicate that the ban on the use of E 171 in foods and supplements is insufficient. Human exposure also occurs through all products that come into contact with the oral mucosa, therefore toothpastes, lipsticks and other cosmetics, even in powder form if inhaled.

The expectation of a ban on drugs

Drugs are another large field of population exposure to titanium dioxide nanoparticles. The dangerous additive is in fact widely used as an opacifier useful for stabilizing the active ingredients.

The decision of the European Commission on titanium dioxide in medicines is expected in 2025 and will take into account the evaluation report commissioned from the EMA (European Medicines Agency) for April 2024.

Marta Strinati


(1) Julien Vignard, Aurelie Pettes-Duler, Eric Gaultier, Christel Cartier, Laurent Weingarten, Antje Biesemeier, Tatjana Taubitz, Philippe Pinton, Cecilia Bebeacua, Laurent Devoille, Jacques Dupuy, Elisa Boutet-Robinet, Nicolas Feltin, Isabelle P. Oswald , Fabrice H. Pierre, Bruno Lamas, Gladys Mirey & Eric Houdeau (2023) Food-grade titanium dioxide translocates across the buccal mucosa in pigs and induces genotoxicity in an in vitro model of human oral epithelium. Nanotoxicology, 17:4, 289-309,

(2) Marta Strinati. Titanium dioxide in food. GIFT (Great Italian Food Trade).

(3) Marta Strinati. Stop to titanium dioxide, interview with Francesco Cubadda, ISS expert. GIFT (Great Italian Food Trade).

(4) Dario Dongo. Titanium dioxide in food and supplements, stop from 7.2.22. GIFT (Great Italian Food Trade).

Marta Strinati

Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".

Related Articles

Latest Articles

Recent Commenti

Translate »