A study from the American Thoracic Society has shown a link between pregnant mother’s nut consumption and a raised asthma risk in their offspring. Published in the July 15 issue of the American Journal of Respiratory and Critical Care Medicine, the study found the asthma risks rising by nearly 50%.

According to the American Academy of Allergy, Asthma & Immunology, 4 % of American children have food related allergies while 3 million or a little more than 1 percent of people in the United States are allergic to peanuts or tree nuts.

A majority of these allergies develop as a result of repeated sensitization to an allergen and with each exposure the reactions tend to increase. Children les than three years of age are not recommended any nuts as their immune systems are still developing and therefore they would be more susceptible to allergies.

According to study author Saskia Willers, a doctoral candidate at Utrecht University in the Netherlands, “consistent positive associations between maternal nut product consumption, such as peanut butter, during pregnancy and wheeze, dyspnea (shortness of breath), steroid use, doctor-diagnosed asthma and persistent wheeze in children from 1 to 8 years of age.”

Dr. Jennifer Appleyard, chief of allergy and immunology at St. John Hospital and Medical Center in Detroit said, "If you say avoid nuts in children, and for nursing mothers because peanut protein can be transferred through milk, do we need to take it a step further and limit nuts during pregnancy?"

Researchers say they don’t know why nuts eaten during pregnancy can cause a problem, but they feel that there is a possibility that allergens from nuts go into the womb and interfere with the developing baby’s immune system, which predisposes the child to asthma once it’s born.

Dr Dave Hinda feels that pregnant women should limit their nut intake but not totally avoid them. "I don't want someone to think peanut butter is poison," Hinda said. "A small amount seems fine. It's the several days a week moms who had children with problems."