In particular, kids in big cities are more than twice as likely to have peanut and shellfish allergies compared to rural communities. "We have found for the first time that higher population density corresponds with a greater likelihood of food allergies in children," said Doctor Ruchi Gupta of Northwestern University. "This shows that environment has an impact on developing food allergies."
"Similar trends have been seen for related conditions like asthma. The big question is – what in the environment is triggering them? A better understanding of environmental factors will help us with prevention efforts." Gupta said some of her future research will focus on trying to identify the environmental causes.
The study included 38,465 children, 18 years and under, who comprised a representative sample of U.S. households. Their food allergies were mapped by ZIP code. The key findings of the study: In urban centres 9.8 percent of children have food allergies, compared to 6.2 percent in rural communities, almost a 3.5 percent difference.
Peanut allergies are twice as prevalent in urban centres as in rural communities, with 2.8 percent of children having the allergy in urban centres compared to 1.3 percent in rural communities. Shellfish allergies are more than double the prevalence in urban versus rural areas; 2.4 percent of children have shellfish allergies in urban centres compared to 0.8 percent in rural communities.
Food allergies are equally severe regardless of where a child lives, the study found. Nearly 40 percent of food-allergic children in the study had already experienced a severe, life-threatening reaction to food.
The study controlled for household income, race, ethnicity, gender and age. It tracked food allergy prevalence in urban centres, metropolitan cities, urban outskirts, suburban areas, small towns and rural areas.
MEDICA.de; Source: Northwestern University