Nanotechnologies have revolutionized food technology with changes to food production, manufacturing, and processing that are intended to make our food safer and healthier.

Phytosanitary products, processing aids, food additives, and surfaces that touch food in storage can all transfer nanoparticles that might be consumed by humans. 

In a review published in Frontiers in Allergy today, Mohammad Issa, at the Universite Paris-Saclay, and colleagues pointed out that such a significant change to food production could have unforeseen health consequences.

 The team presented evidence suggesting that nanoparticles cross the placenta to reach developing fetuses and leave them at greater risk of potentially life-threatening food allergies.

“Due to the immunotoxic and biocidal properties of nanoparticles, exposure may disrupt the host-intestinal microbiota’s beneficial exchanges and may interfere with intestinal barrier and gut-associated immune system development in fetus and neonate,” said Dr Karine Adel-Patient, corresponding author of the study. 

“This may be linked to the epidemic of immune-related disorders in children, such as food allergies – a major public health concern.”

Allergies on the rise Food allergies occur when the immune system overreacts to proteins found in food. Children should usually develop oral tolerance, which allows them to eat without their bodies treating dietary proteins as a threat, but if the immune system or the intestinal barrier are compromised, they may instead become sensitized and develop an allergic reaction.

Food allergies affect between 2-5% of adults and 6-8% of children, and prevalence has risen sharply in recent decades. We know that environmental factors play a significant role in allergy development, and the higher prevalence in children suggests that early life environmental factors are likely key.

Dietary practices and the environment affect gut health in young children, and the deprivation of gut microbiota and a wide range of dietary proteins can affect the development of oral tolerance. Nanoparticles passed on

To understand how nanoparticles can disrupt this delicate balance, the team focused on three nanoparticle-bearing additives which are regularly found in food.