New research coming in from Holland shows that expectant mothers who eat nuts (or nut products like peanut butter) daily during pregnancy increase their children’s risk of developing asthma by more than 50 percent over women who rarely or never consume nut products during their pregnancy.
“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.
The study appeared in the second July issue for July of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
Maternal consumption of allergenic foods during pregnancy may increase the risk that the fetuses they carry would become sensitized to certain allergens. Research on the topic, however, has been contradictory and often inconclusive.
Nearly 4,000 expectant mothers from the Prevention and Incidence of Asthma and 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. As studies like this go, this one is large and fairly comprehensive.
“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 the lead author. “Daily versus rare consumption of nut products—which we assumed was largely peanut butter—was consistently and positively associated with childhood asthma symptoms.”
The association remained even after controlling for the child’s diet.
Additionally, the authors noted, there was a small effect of daily maternal fruit consumption during pregnancy on reducing the risk of wheeze in children, but other factors such as health-consciousness and consumption of prenatal vitamins may have been contributing factors in ways that were undetectable in this study’s design.