Junk food and bacteria implicated in food allergy epidemic

Many theories have been posed to explain the rise in childhood food allergies in western countries. Recent studies point to an impaired skin barrier – which has long been linked to the development of eczema, allergic rhinitis, asthma, and food allergy; and the increasing consumption of ‘junk food’ diets.

Using data collected during the Learning Early About Peanut Allergy (LEAP) study, British researchers have expanded on previous research to show that patients with eczema whose skin was colonized with Staphylococcus aureus were more likely to have food allergies, particularly to peanut, compared to those who didn’t have an infection with this bacteria. The connection appears independent of the severity of eczema, and of whether or not the child was fed peanut from a young age.

Just how the bacterial colonisation of eczema-impaired skin leads to food allergy has yet to be elucidated. While still too early to say, these findings may suggest that control of S. aureus skin infection in children with eczema could help to prevent the development of food allergy.

The link between junk food and development of food allergies has recently focussed on advanced glycation endproducts, or ‘AGEs’, that are found in high levels in highly processed foods, as well as other sources such as cooked meats. High levels of AGEs in the body, which may possibly result from consuming AGE-rich foods, have previously been linked to a number of inflammatory conditions including diabetes and rheumatoid arthritis.

Researchers in Italy have now shown that children with food allergies have higher levels of AGEs in their bodies than healthy children without allergies. Children with respiratory allergies showed no such differences. The team also found that children with higher levels of AGEs consumed more food containing these substances.

Possible explanations for the link include direct interaction of the AGEs with immune cells, or the AGEs having a detrimental effect on the gut barrier.

Caution is advised in interpreting these results study due to the small study size which involved only 23 children with food allergies, 16 with respiratory allergies and 22 healthy children without allergies.

References:

  1. Tsilochristou et al. 2019. “Association of Staphylococcus aureus colonization with food allergy occurs independently of eczema severity”. Journal of Allergy and Clinical Immunology, DOI. j.jaci.2019.04.025.
  2. Canani et al. 2019. “How junk food can contribute to the food allergy epidemic: the potential role of advanced glycation endproducts”. Presented at the 52nd Annual Meeting of ESPGHAN.