Nut Products Linked to Asthma in Children

"We were pretty surprised to see the adverse associations between daily versus rare nut product consumption during pregnancy and symptoms of asthma in children, because we haven't seen this in similar previous studies," said the study's lead author, Saskia M. Willers, M.Sc.

Nearly 4,000 expectant mothers from the Prevention and Incidence of Asthma and Mite Allergy study conducted by the Dutch government completed a dietary questionnaire that asked how often they consumed vegetables, fresh fruit, fish, eggs, milk, milk products, nuts and nut products during the last month. Their children's diets were also assessed at two years of age, and their asthma and allergy symptoms were assessed yearly until eight years of age. By the end of the eight years, the researchers had complete data for 2,832 children and their mothers.

"The only consistent association between the maternal intake of the investigated food groups during pregnancy and childhood asthma symptoms until eight years of age that we found was with nut products," said Willers. "Daily versus rare consumption of nut products—which we assumed was largely peanut butter—was consistently and positively associated with childhood asthma symptoms, including wheeze, dyspnea, doctor diagnosed asthma and asthma-associated steroid use."

"These findings emphasize the critical important of additional investigations into the environmental exposures for both mother and child that underlie the pathogenesis of asthma," says John E. Heffner, M.D., past president of the American Thoracic Society. "It is important, however, to emphasize that such associations do not confirm a causative linkage."

While a strict low-allergen diet is not recommended for most expectant mothers because it risks both maternal and foetal malnutrition, Willers notes that peanuts may be the exception to that general recommendation. "Peanut is a potent allergen, and peanut allergy is associated with anaphylactic shock and is less likely to be outgrown than other allergies."; Source: American Thoracic Society