Introducing solid foods while continuing to breast feed could prevent child allergies

Introducing solid food with breast milk after the 17th week of birth could reduce food allergies in babies, according to University of Southampton research.

The research, led by Dr Kate Grimshaw, dietitian and senior research fellow at the University, say that giving the baby solid food beside breast feeding helps it develop a better, stronger immune system to fight food allergies.

"Introducing solid foods alongside breastfeeding can benefit the immune system," Dr Grimshaw explains. "It appears the immune system becomes educated when there is an overlap of solids and breast milk because the milk promotes tolerogenic mechanisms against the solids.

"Additionally, our findings suggest 17 weeks is a crucial time point, with solid food introduction before this time appearing to promote allergic disease whereas solid food introduction after that time point seems to promote tolerance."

Infants are largely intolerant of solid food before four to six months of age. This is thought to be due to the infant gut being relatively immature, which may cause symptoms of food allergy.

The study, funded by the UK Food Standards Agency and published in Pediatrics, recruited 1140 infants at birth from the Hampshire area in a study known as 'PIFA'. 41 of these children went onto to develop a food allergy by the time they were two years of age. The diet of these infants was compared with the diet of 82 infants who did not develop food allergy by the time they were two.

Which infants are at risk of developing allergic disease? A number of factors appear to increase the risk of developing allergic disorders. We have no control over some risk factors such as family history, whilst there are other environmental factors that we might be able to influence. Identified risk factors for developing allergic disease include:

Family history of allergic disease in a parent or sibling (family history of allergic disease in both parents OR a parent and a sibling is associated with a further increased risk)
Introduction of cow's milk or soy milk formula before 3 - 4 months of age (an increased risk for eczema and food allergy)
Introduction of solid foods before 3-4 months of age (an increased risk for eczema and food allergy)
Birth in Spring - a risk for hay fever (seasonal allergic rhinitis)
Passive exposure to cigarette smoke (a risk for increased respiratory symptoms)

The team found that children who had developed allergies began eating solid food earlier than children with no allergies - roughly, at age 16 weeks or earlier. Children with allergies were also more likely to not be being breastfed when the mother introduced cow's milk protein, from any source. Women who are not breastfeeding are encouraged to introduce solids after 17 weeks of age, Dr Grimshaw says.