Inner-city kids, who are already known to have higher rates of asthma and certain allergies, may also be more likely than kids in the general population to have at least some food allergies, according to a recent study.

The study researchers reviewed data on 516 inner-city children from birth through age 5 in Boston, Baltimore, St. Louis and New York City. Each year, the study measured the children’s exposure to household allergens, did physical examinations, reviewed the children’s diets and health histories and took blood samples at ages 1, 2, 3 and 5 years to measure antibodies to milk, eggs and peanuts.

More than half of the kids in the study were classified as sensitive to milk, eggs or peanuts and nearly ten percent had a full blown food allergy, with the most common peanuts (6 percent) followed by eggs (4.3 percent) and milk (2.7 percent). The rate was higher than the national average, which is six percent, according to data from the National Institutes of Health.

An additional 17 percent were termed “possibly allergic,” based on antibody levels and twenty nine percent were termed “sensitive but tolerant.

“Our findings are a wake-up call, signaling an urgent need to unravel the causes, contributors and mechanisms that drive the high prevalence of food allergies among an already vulnerable group known for its high risk of asthma and environmental allergies,” said Robert Wood, M.D., director of pediatric allergy and immunology at Johns Hopkins and the senior investigator of the study.

The researchers were surprised to find that breastfed children seemed more likely to have food allergies, while children living in houses with higher levels of endotoxin, a molecule that’s released by certain types of bacteria, were less likely to have food allergies. And children with food allergies were also more likely to develop environmental allergies, wheezing and eczema.

The researchers say that it is possible that earlier lower estimates of food allergies among inner-city children was a result of under diagnosis and under treatment and recommend additional studies.

The study was published in Journal of Allergy and Clinical Immunology.