By examining a person’s genetic code, scientists found that a 10% rise of African ancestry is linked to a 25% increase in the chances of being sensitized to peanuts, i.e. having an allergic reaction to peanuts, researchers from the Children’s Memorial Hospital, Chicago, and the Boston Medical Center, Boston, reported in the journal Pediatrics.

The scientists examined the genetic profiles of 1,104 children to find out whether there might be a link between genetic ancestry and the presence of allergic antibodies to food. They concluded that African-American kids have a higher chance than other children of having allergic antibodies to food allergens.

They also found that those with an African ancestry were more likely to have allergic antibodies to peanuts at levels which usually mean the person has a clinical peanut allergy.

Team leader, Rajesh Kumar, MD, MS, said:

“National studies show there are higher rates of allergic antibodies to food in African American individuals. 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.”

However, the scientists did not detect the same risk with self-identified race which was associated with milk and egg allergic antibodies.

The authors suggest that various food allergy promoting factors linked to race may be different than the ones associated with genetic ancestry.

Egg and milk allergy, for example, may be driven by when self-identified races introduce them to a child’s diet. A peanut allergy is more impacted by genetic ancestry, and could be linked to other genetic factors, such as vitamin D levels in early life.

This study, involving 1,104 children with an average age of 2.7 years, from an urban, multi-ethnic cohort (60.9% black and 22.5% Hispanic), is ongoing.

Dr. Kumar said:

“The study underlines the need for continued follow up especially in exploring environmental and genetic factors so we can answer ‘why’ there this association of peanut allergy with African ancestry. Further rigorous research is needed to study the genetic and environmental factors which influence the rates of food allergy in U.S. urban populations.”

In an Abstract in the journal, the authors wrote:

“Black children were more likely to be sensitized to food allergens and were sensitized to more foods. African ancestry was associated with peanut sensitization.”

Written by Christian Nordqvist