Genetics, Lifestyle & Environment Influence Food Allergy Risk

Genetics, lifestyle, and environment influence the risk of food allergies in early life. A review article published in Annals of Allergy, Asthma, and Immunology conducted a literature review of all scientific articles on food allergy and food sensitization published after 2015 and explored the following topics:

• the genetic risks for food allergy
• links between atopic dermatitis (AD) and food allergy
• dietary allergen exposures in early life
• maternal antigen (substance that induces an immune response) consumption during pregnancy and lactation
• breastfeeding and formula feeding
• introduction to solid foods
• lifestyle and environmental exposures
• the gut microbiome and metabolome in food allergy
• early immune biomarkers of food allergy

One of the most significant findings in the study was that adopting a Western lifestyle (one that’s more industrialized with low microbial diversity) may contribute to an increased incidence of food allergies due to the hygiene hypotheses – the idea that the lack of exposure to a diverse array of microbes at an early age leads to a weakened immune system and in turn, more illness later in life. The researchers found that larger family size, exposure to pets, vaginal deliveries, and farming are all associated with lower rates of atopic dermatitis and hay fever and result in a lower risk for allergic diseases. Scientists also found that microbiomes with less diverse and abundant bacterial populations have a higher risk of developing food allergies and sensitivities.

Many studies show that breastfeeding protects against food allergies through its role in shaping the gut microbiome and immune system in early life, but maternal variations in milk composition also play a meaningful role and can modify those benefits.

Other important findings in the review study included:

• The early introduction of solid foods, such as peanuts, can significantly decrease the risk of developing a food allergy or sensitivity
• Genetic characteristics associated with food allergies and sensitivities include the number of immediate family with allergic diseases, and the major histocompatibility complex genes, which can increase the risk of peanut, cow’s milk, and egg allergies
• One in every three children with atopic dermatitis is at risk for food allergies. Scientists hypothesize this increased risk could be due to an impaired skin barrier, which creates skin sensitization to foods before ingestion.