In its latest analysis, AVICENN, a French specialist association that monitors nanomaterials, examined the nanomaterial content of everyday products, foodstuffs, cosmetics, textiles and hygiene products available on French shelves.Nanoparticles were detected in 20 out of 23 products, including infant milk, but also ham, vitamins and dog food. Without being listed in the ingredients list, nano silica was found in food products, and nano titanium dioxide was found in the blotting cloth under the cutlet of chicken.

According to the authors, this raises the question of the extent of use of nanoparticles in our everyday products. A consumer group (Que Choisir) highlighted the shortcomings of the regulation, as none of the products were marked as containing nanoparticles, even though it is mandatory for food and cosmetic products.

Que Choisir conducted a similar survey on the nanomaterial content of the products 5 years earlier, and it has now commented that the situation had not improved much since then.

Evidence on the health effects of nanomaterials is insufficient to draw conclusions. According to some research, their dietary intake can lead to inflammation of the intestinal tract, damage to DNA and cells, and their inhalation can lead to inflammation of the lungs and heart problems.

According to new research, by passing through the placenta and entering the breast milk, they can make the baby more vulnerable to allergies by accumulating in the intestine instead of being absorbed and causing changes in the intestinal microbiome.

The review studied the findings of effects of nanoparticles in the development of food allergies. Food allergy (FA) is an inappropriate immune response against dietary antigens. Various environmental factors during perinatal life may alter the establishment of intestinal homeostasis, thereby predisposing individuals to the development of such immune-related diseases. Among these factors, recent studies have emphasized the chronic dietary exposure of the mother to foodborne inorganic nanoparticles (NP) such as nano-sized silicon dioxide (SiO2), titanium dioxide (TiO2) or silver (Ag). Indeed, there is growing evidence that these inorganic agents, used as food additives in various products, as processing aids during food manufacturing or in food contact materials, can cross the placental barrier and reach the developing fetus. Excretion in milk is also suggested, hence continuing to expose the neonate during a critical window of susceptibility. Due to their immunotoxical and biocidal properties, such exposure may disrupt the host-intestinal microbiota's beneficial exchanges and may interfere with intestinal barrier and gut-associated immune system development in fetuses then the neonates. The resulting dysregulated intestinal homeostasis in the infant may significantly impede the induction of oral tolerance, a crucial process of immune unresponsiveness to food antigens.

In light of the ban on titanium dioxide, French authorities have cautioned against the use of nanomaterials in food, stressing the unknown factors.