Health aNd Fitness Guide

Exposure to secondhand smoke in early infancy can increase a child’s risk of developing allergies, say Swedish researchers. A team in Stockholm analyzed questionnaires filled out by parents of more than 4,000 families when their children were aged two months, 12 months, two years and four years.

The researchers also collected blood samples from over 2,500 children aged four to check for presence of immunoglobin E (IgE), which is released by the immune system in response to the allergens. High levels of IgE indicate sensitization to allergens. The researchers found no evidence that smoking during pregnancy affected a child’s risk of becoming sensitized to certain allergens. Compared to children of nonsmokers, children exposed to secondhand smoke during early infancy were almost twice as likely to be allergic to inhaled allergens, and about 50 per cent more likely to have food allergies.