The mysterious world of allergies got a little stranger yesterday as a new study concluded that nut allergies in children can be greatly reduced if their mothers (if they are themselves not allergic to nuts) eat tree nuts and peanuts while they are pregnant.
It is not an urban myth that peanut allergies in children have increased in recent years. It is not only real, but the magnitude of the change is astounding. Indeed, during the period from 1997 to 2010, the prevalence of peanut allergies has risen by 3.5-fold: From 0.4 percent in 1997 to 1.4 percent in 2010.
ACSH s Dr. Gilbert Ross says, This is a large increase over a very short period of time. While no one may understand exactly what is going on, it certainly seems to be real, and the magnitude of the change is unusual.
Just published in JAMA Pediatrics, researchers at Dana-Farber Children s Cancer Center in Boston, examined the relationship between the association between pregnant mothers eating peanuts or tree nuts (there is commonly an overlap between peanut and tree nut allergies) and the risk of their children subsequently developing nut allergies later on.
The study involved more than 8,000 children, and identified 308 cases of food allergies, of which 140 were nut related. Non-allergic mothers who ate the most nuts (five or more times per week) gave birth to children with the lowest risk of developing nut allergies. This trend did not hold true for mothers who themselves had nut allergies. In fact, these mothers tended to have children who were more likely to have nut allergies. but this trend was not statistically significant and should be interpreted with caution.
Lead author, A. Lindsay Frazier, M.D. said, Our study supports the hypothesis that early allergen exposure increases the likelihood of tolerance and thereby lowers the risk of childhood food allergy. Additional prospective studies are needed to replicate this finding. In the meantime, our data support the recent decisions to rescind recommendations that all mothers avoid [peanuts and tree nuts] during pregnancy and breastfeeding.
In an accompanying editorial entitled To Eat or Not to Eat. What Foods Are Safe to Consume During Pregnancy? Ruchi Gupta, MD, of the Center for Healthcare Studies at Northwestern University commented For now, though, guidelines stand: pregnant women should not eliminate nuts from their diet as peanuts are a good source of protein and also provide folic acid, which could potentially prevent both neural tube defects and nut sensitization. So, to provide guidance in how to respond to the age-old question To eat or not to eat? mothers-to-be should feel free to curb their cravings with a dollop of peanut butter!