Breastfeeding Benefits & Barriers: Prevention of Allergies & Asthma

Businco evaluated the prophylactic effect of exclusive breastfeeding until 6 months of age on the development of atopic disease in 101 newborns with a strong family history of allergic disease. This study further confirmed that prolonged breastfeeding or breastfeeding supplemented with soy milk decreased the incidence of atopic disease by 2 years of age ( Businco, 1983 ).

A Finnish study showed a significant decrease in substantial atopic disease at age 17 years for children breastfed for more than 6 months compared to not breastfed or breastfed for less than one month ( Saarinen, 1995 ).

A meta-analysis of full term infants in 18 prospective cohort studies showed that children with a family history of atopic disease who were exclusively breastfed for at least 3 months had a 42% reduction in the risk of atopic dermatitis compared to those breastfed for less then 3 months ( AHRQ, 2007 ). There is no good data supporting limiting a breastfeeding mother's diet to prevent allergic dermatitis in their infants ( AAP Nutrition/Atopic Disease, 2008 ).

Exclusive breastfeeding up to 4 months of age was associated with a reduced risk of asthma diagnosed by a physician (with an odds ratio of 1.25); a reduced risk of wheezing at 5 years of age (OR: 1.31); and a reduced risk of sleep disturbance due to wheezing at 5 years of age (OR: 1.42) ( Oddy, 1999 ).

In the PROBIT study, a large randomized trial of breastfeeding promotion in Belarus (See The Growth of Breastfed Infants in the Developed World for more information on this study), they studied the effect of prolonged and exclusive breastfeeding on the risk of allergy and asthma in over 13,000 children with no specific tendency or family history of allergies or asthma. At 3 months of age, the prevalence of exclusive breastfeeding was 43% in the experimental group compared to 6% in the control group. At 6 years of age, there was no difference in the percentage of children with wheezing at any time, or diagnoses of asthma, hayfever or eczema between the 2 groups. There was also no difference in the prevalence of positive skin tests to 5 inhaled allergens between the groups ( Kramer, 2007-2 ).

A meta-analysis of the association of breastfeeding and asthma in 12 prospective studies that met inclusion criteria found a summary odds ratio of 0.7 (95% CI 0.6, 0.81) for the protective effect of breastfeeding. These studies all evaluated exclusive breastfeeding for at least 3 months ( Gdalevich, 2001 ).

Breastfeeding is not a guarantee that a child will not develope allergies, eczema or asthma. However, particularly in families with a strong family history of these problems, exclusive breastfeeding for 4-6 months may help reduce the risk of allergic disease.