Introduction of solids and the development of food allergy

introduction of solids and the development of food allergies

There is a great deal of debate and conflicting information out there on when the right time to introduce solids is. Pediatric dietician, Kath Megaw to present the latest research-based evidence for when to introduce solids.

Complementary Feeding

The World Health Organization (WHO) now recommends the term weaning be replaced with the term complementary feeding. Complementary feeding incorporates any nutrient-containing food or liquid other than breastmilk.

There is universal consensus that breastmilk remains unchallenged as the milk of choice for all infants. There is however conflicting advice with respect to the age at which complementary feeding should occur. Most allergy and gastrointestinal opinion leaders suggest that complementary feeding may occur from 4 months of age onwards. (References – 1- 4) WHO however recommends that complimentary feeding should occur only after 6 months of age. (5)

How does complimentary feeding affect the development of food allergy?

Kramer and Kukuma (6) looked at all the available evidence concerning the effects of exclusive breastfeeding for 6 months vs exclusive breastfeeding for 3 to 4 months followed by complementary feeding. They looked at 20 independent studies. They were unable to establish evidence for a significant reduction in the risk of allergies for exclusively breastfed infants up to 6 months of age and those exclusively breastfed for only 3 – 4 months followed by mixed feeding.

Observational studies suggest that complementary feeding with 4 or more solid foods in the first 4 months of life may increase the risk of developing allergic disease (but not food allergy). There is no evidence that delaying the introduction of solid foods beyond 4 months of age is protective, and some evidence suggests that the delayed introduction of solids may promote allergies (7).

There is a significant body of evidence with respect to oral tolerance that in Africa, Asia and middle Eastern countries where peanuts are consumed throughout pregnancy and early childhood have low rates of Peanut allergy compared with western industrialized societies such as the UK and USA, where Peanut Allergy is high despite the low consumption in pregnancy, infancy and childhood. (8)

There are studies in humans to suggest that early introduction of food such as peanut, cereal grains and egg, is not associated with an increased prevalence of allergy to these foods and may possibly serve as a means of inducing oral tolerance to that protein. More studies are needed to guide public health strategies.

In summary, international consensus does not support allergen avoidance as a strategy for the primary prevention of food allergy. Starting solids at 6 months of age alongside breastfeeding will not put an infant of increased allergy risk.

References

  1. Greer FR et al: Effects of early nutritional interventions on the development of atopic disease in infants….aediatrics 2008;121:183-91
  2. Infant feeding advice:Australasian Society of Allergy and Immunology
  3. Agostoni C et al. Complementary feeding: a commentary by the ESPHGHAN Committee on Nutrition. J Pediatr Gastoenterol Nutr 2008;46:99-110
  4. Boyce JA et al. Guidelines for the diagnosis and management of food allergy in the United States. J Allergy Clin Immunol 2010: 126:S1-58
  5. World Health Organization, Breastfeeding Recommendations, 2010
  6. Kramer MS, Kakuma R. The optimal duration of exclusive breastfeeding: a systematic review. Adv Exp Med Biol 2004;554:63-77
  7. Du Toit G et al: Can food allergy be prevented? The current evidence; Food Allergy in Children: Paediatric Clinics of North America 2011;58:(2): 492
  8. Shek LP, et al. A population based questionnaire survey on the prevalence of peanut, tree nut and shellfish allergy in 2 Asian populations. J Allergy Clin Immunol 2010;126:324-31, 331

By Kath Megaw