Breast milk linked to nut allergies

An Australian study has linked the rise in nut allergies amongst Australian school aged children to breast feeding in the first six months of life, suggesting that breast feeding provides no protection against nut allergy.

Recent studies have noted a rise in allergies, now affecting around 10% of children. The recommendation infants be breast fed exclusively till 6 months and that solids be delayed till then  has been put forward as a reason for this increase.The Australian Society for Clinical Immunology and Allergy (ASCIA) now recommends that infants be introduced to solids foods between 4-6 months of age, while continuing to be breast fed, for protection against allergy. 

Thes study was undertaken in the Australian Capital Territory (ACT) between 2006 and 2009. Over 15,000 parents completed the ACT Kindergarten Health Check which asked, amongst other things, whether their child had ever had an allergic reaction to peanut or nut products. Parents were also asked about how long their child was breast fed and whether the child was fed any other foods or fluids during the first 6 months of breast feeding.

The study found:-

• Overall 3.9% of children were reported by their parents to have a nut allergy. The prevalence of peanut allergy was 3.2%.
• The mean duration of breastfeeding was 9.9 months with 90% of children breast fed. Over 4% had a nut allergy. Of the 10% of children not breast fed, 2.7% had a nut allergy
• 65.4% of children were fed foods and fluids other than breast milk during the first 6 months of life. These included infant cereal, infant formula, vegetables and fruit juices.
• Children who were exclusively breast fed in the first 6 months were more likely to have a nut allergy than those that weren't.
• Protection against nut allergy occurred in children who were fed foods and fluids other than breast milk in the first 6 months

The evidence suggests that children can become sensitized to nuts through breast milk. Sensitization can occur not only through food, but also through the use of creams/ lotions etc that contain peanut products. While a direct cause and effect relationship cannot be concluded from this study because of its design, it does add to the argument that breast feeding  may not be protective against nut allergy.

Reference:

Paton J et al. Infant feeding practices and nut allergy over time in Australian school entrant children. International Journal of Pediatrics Vol 2012 doi:10.1155/2012/675724