GIF-SUR-YVETTE, France — Nanotechnology has rapidly transformed food production, manufacturing, and processing in recent years, with the goal of enhancing food safety and health. However, new research suggests that their use in making foods safer could have unexpected health consequences for babies. An international team has found evidence that nanoparticles can cross the placenta during pregnancy and reach the fetus, putting infants at higher risk of developing potentially life-threatening food allergies after birth.
“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,” says corresponding author Dr. Karine Adel-Patient, in a media release. “This may be linked to the epidemic of immune-related disorders in children, such as food allergies – a major public health concern.”
Food allergies generally impact between two and five percent of adults and even more children (6-8%), with their prevalence continuously on the rise in recent decades. So far, researchers say environmental factors play a key role in allergy development, but the higher prevalence in children suggests that environmental factors during the earliest stages of life are of particular importance. Dietary practices in addition to environment impact gut health in young children, which may ultimately affect food tolerance.
To better understand how nanoparticles in the food additives that mothers-to-be consume disrupts this link, a team from Université Paris-Saclay examined three nanoparticle-bearing additives that are common ingredients in food.
“Such agents can cross the placental barrier and then reach the developing fetus,” explained Adel-Patient. “Excretion in milk is also suggested, continuing to expose the neonate.”
Although there’s more substantial evidence showing that nanoparticles can cross this barrier in mice, there is evidence showing that this also occurs in humans. The nanoparticles are not absorbed by the gut. Instead, they accumulate and affect the surrounding bacterial environment within the eater’s microbiome. Given that the gut is heavily involved with immune function, this becomes a concern with allergies. Additionally, nanoparticles impact the epithelium intestinal barrier, which may also explain poor reactions to dietary proteins.
Despite it being difficult to gather data on immunotoxicity in humans, the team was able to show that nanoparticles negatively affect gut-associated lymph tissue. This suggests an even greater impact on the immune system than previously known and the results are consistent with animal studies.
The researchers do note that their study had limitations, including that the nanoparticle exposure among animals was much higher than humans usually receive while eating. Still, the team’s work encourages researchers and scientists to consider the effects of food additives on allergy development.
“The impact of such exposure on the development of food allergy has not been assessed to date,” Adel-Patient warns. “Our review highlights the urgent need for researchers to assess the risk related to exposure to foodborne inorganic nanoparticles during a critical window of susceptibility and its impact on children health.”
The findings are published in the journal Frontiers in Allergy.