Peanut (and other nut) allergies are common in children, and are on the rise, with an estimate of 3 per 100 children affected in Australia. Although 20% will outgrow their allergy, exposure to peanuts can result in severe anaphylaxis for other sufferers. One of the questions we often get asked is whether it is safe to eat peanuts during pregnancy and if this will increase the risk of peanut allergies for the baby.
Advice on this topic has changed from one extreme to the other over decades, with the American Association of Pediatrics stating in 2000 that women should completely refrain from exposure to peanuts while pregnant, breastfeeding and for their babies up until the age of 3. There was no evidence of a reduction in the growing number of allergies following this recommendation, and in 2008 the recommendation was abandoned.
The theory of sensitisation is that babies who are exposed in utero are more likely to develop allergies than those who were not exposed. Current thinking is changing to the theory of tolerance, where in utero exposure actually increases the tolerance of the baby to the substance meaning that they are less likely to develop life-threatening allergies.
Current recommendations state that there is no evidence of increased nut allergies in women who eat nuts during their pregnancy. In fact, a study from December 2013 (JAMA paediatrics) showed an association between a reduction in nut allergies for children of women who consumed nuts while pregnant. This study of over 8000 children found that women who had higher levels of nut consumption (5 times per month) were one third less likely to have a child with a peanut allergy compared with women who ate peanuts less than once per month.
The exception to this was women who have a nut allergy themselves, where eating nuts may increase the risk. So as long as you don’t have a nut allergy yourself, don’t feel guilty about the peanut butter sandwich you just ate, it may in fact be helping to protect your little one.