Does Early Exposure to Nuts Lower a Child’s Allergy Risk?

ImageAre children more likely to develop a peanut or tree nut allergy if their mothers eat nuts during pregnancy or while nursing? Over the years, a number of studies have attempted to answer this question, but the results have been inconclusive. According to a new FARE-funded study, eating nuts during pregnancy does not cause food allergies in children. Further, although more studies are needed, it is possible that eating nuts may prevent a child from developing a food allergy.

In an article published online by JAMA Pediatrics on December 23, a research team affiliated with Harvard Medical School reported on their study, which suggests that mothers who do not have allergies and who eat nuts during pregnancy may lower their children’s risk of developing a peanut or tree nut allergy. The study, which was funded by FARE, received considerable media coverage.

The team, led by Dr. A. Lindsay Frazier, looked at the history of 8,205 participants in the Growing Up Today Study 2 (GUTS2) – children who were born between 1990 and 1994. The researchers reviewed records of the mothers’ diet immediately before and during pregnancy, and shortly after the infants’ birth. Of this group, 308 children had a food allergy, including 140 cases of peanut or tree nut allergy.

The incidence of peanut or nut allergies was significantly lower among the children of mothers who did not have food allergies themselves and who ate nuts at least five times per month compared to those who ate these foods less than once per month. “Our study supports the hypothesis that early allergen exposure increases the likelihood of tolerance and thereby lowers the risk of childhood food allergy,” the researchers concluded. They noted, however, that additional studies are needed. “The data are not strong enough to prove a cause-and-effect relationship,” commented one of the authors, Dr. Michael Young. “Therefore, we can’t say with certainty that eating more peanuts during pregnancy will prevent allergy in children. But we can say that peanut consumption during pregnancy doesn’t cause peanut allergy in children.”

A study that should shed more light on this issue is currently underway. The LEAP (for “Learning Early About Peanut Allergy”) Study, conducted by Dr. Gideon Lack and colleagues at King’s College London, has been following 640 children since infancy to determine whether or not exposure to peanuts early in life can prevent the development of peanut allergy. This study, which is co-funded by the National Institutes of Health and FARE, should be completed in 2014.