Washington, July 186 : Gorging on nuts or nut products like peanut butter regularly during pregnancy may not be a good idea for expectant mothers, for this may actually make their children more prone to allergies like asthma.
This new study from the Netherlands has cited that such a regime of regular intake of nut products can actually increase their children's risk of developing asthma by more than 50 percent over women who rarely or never consume nut products during 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 Saskia M. Willers, M.Sc, the study's lead author.
Not only did Willers said that it was "too early to make recommendations of avoidance," she also noted that "it's important for pregnant women to eat healthily, and what is true for many foods is that too much is never good."
She said that maternal consumption of allergenic foods during pregnancy may increase the risk that the foetuses they carry would become sensitized to certain allergens, however the research on the topic, has been contradictory and inconclusive till date.
This Prevention and Incidence of Asthma and Mite Allergy study conducted by the Dutch government conducted a dietary questionnaire on almost 4,000 expectant mothers and asked how often they consumed vegetables, fresh fruit, fish, eggs, milk, milk products, nuts and nut products during the last month.
They also analysed their children's diets at two years of age, and their asthma and allergy symptoms were assessed yearly until eight years of age. This led the researchers to have complete data for 2,832 children and their mothers by the end of the eight years.
"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. 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," said Willers.
This association remained even after controlling for the child's diet. Besides, the authors pointed out that 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.
"These findings emphasize the critical important of additional investigations into the environmental exposures for both mother and child that underlie the pathogenesis of asthma. It is important, however, to emphasize that such associations do not confirm a causative linkage," said John E. Heffner, M.D., past president of the American Thoracic Society.
Willers said that while a strict low-allergen diet is not recommended for most expectant mothers because it risks both maternal and fetal malnutrition, 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," she added.
The study appeared in the latest issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.