An unidentified food allergy can be life threatening for some children, but it is not always clear when screening is appropriate. A new study has found that self-reported black race and African ancestry, determined by genetic analysis, were associated with a high number of sensitizations to food, most notably peanuts. See what researchers have to say about the possible relationships between ethnic background and food sensitization.
Black children are more likely to have some common food allergies and are especially likely to have reactions to peanuts, according to a new study that sought to determine whether allergic antibodies are associated with genetic ancestry.
The study looked at 1,104 children (mean age, 2.7 years) in an urban, multiethnic area. It defined food sensitization as specific immunoglobulin E (sIgE) levels of at least 0.35 kilo units of allergen (kUA)/L for any of 8 common food allergens. Food sensitization was exhibited by 35.5% of participants in the study group, which was 60.9% black and 22.5% Hispanic.
Researchers found that self-reported black race and African ancestry, determined by genetic analysis, were associated with a high number of sensitizations to food, most notably peanuts. Egg and milk allergies also showed similar associations, although the results were not statistically significant for milk.
“National studies show there are higher rates of allergic antibodies to food in African American individuals,” said lead researcher Rajesh Kumar, MD, MS, associate professor of pediatrics at Northwestern University Feinberg School of Medicine and a pediatric allergist at Children’s Memorial Hospital. “We found similar results but we also found that an individual’s genetic ancestry [the proportion of one’s ancestors which came from each continental group determined by genetic analysis] increased the risk of a person having allergic antibodies to peanut above a level which is often associated with peanut allergy.”
Self-identified race did not seem to hold the same risk with peanuts, although it was associated with allergic antibodies to milk and eggs, Kumar said. That suggests that food allergy factors associated with race may be different compared with those associated with genetic ancestry. For example, dietary patterns of food introduction may differ by self-identified race and influence egg and milk allergies, but peanut allergies could be affected by other genetic or early life factors, such as vitamin D levels.
“The study underlines the need for continued follow up especially in exploring environmental and genetic factors so we can answer ‘why’ there [is] this association of peanut allergy with African ancestry,” said Kumar.