New research suggests a link between early-life secondhand smoke exposure and the development of food allergies.
“There is compelling evidence to suggest that exposure to secondhand smoke could increase an individual’s risk of becoming sensitized to a food. In other words, developing antibodies against a food,” says Laura Feldman a researcher at Toronto’s Hospital for Sick Children.
Feldman visited Stockholm, Sweden to analyze data that researchers had conducted there. She looked at 3,735 infants from a birth cohort in 1994 to 1996. They were followed in the study until they were 16. Parents had been asked detailed questions about their smoking habits and if and how their child reacted to consuming certain foods at various stages of their life. Blood tests were conducted as well to measure whether the children had IgE reactivity to common food allergens.
“We found that children whose parents smoked during the child’s infancy had 44 percent higher odds of having IgE-associated symptoms to foods,” Feldman said. “We also found that, at 16 years, these children had higher odds of having IgE-associated symptoms to egg and peanut.”
It’s unclear how secondhand smoke would lead to the development of food allergies, but Feldman says there are a few theories. “It’s possible that secondhand smoke exposure in early life disrupts a child’s skin barrier, which might lead to children being exposed to food proteins through their skin which is theorized to increase children’s risk of food allergy,” she explains. She says it’s also possible that secondhand smoke exposure may interact with the child’s genes, although this has not been well-studied to date.
Feldman says a 24-year follow-up is underway. “This will allow us to look at the impact of early life factors on allergic diseases not only among children and adolescents, but young adults as well.”
An abstract describing the study findings was published in the Journal of Allergy and Clinical Immunology in February.