The prevalence of allergies and asthma has greatly increased in the Western world over the past few decades. Several hypotheses have been put forth to explain this situation, but we still do not have a clear explanation for it. The Canadian Paediatric Society (CPS) and many other authorities recommend delaying the introduction of cow’s milk, nuts, and other common allergens, in the hopes of preventing the onset of allergies. A new study, however, has found that doing so does not seem to have an influence on the development of wheezing or eczema later on.
Many recent studies do not support the recommendation to delay introducing foods such as eggs, nuts and cow’s milk. As part of the latest study on the subject, researchers tracked eczema and asthma symptoms in nearly 7,000 infants until the children were four years old.
At the age of two, 31 percent of the toddlers showed symptoms of wheezing, but this prevalence dropped by half over the next year. Eczema was present in 38 percent of two-year-olds, but that number fell to 18 percent two years later.
Initially, it seemed that the children who had eaten nuts before they were six months old exhibited more wheezing. But after considering smoking among the mothers, and other asthma risk factors, there was no longer any sign that eating nuts was linked to a higher risk of allergies. Giving young babies cow’s milk or eggs also does not appear to increase their risk of developing asthma or eczema later on. However, if the child shows signs of an allergic reaction, such as breaking out in hives or having trouble breathing, parents should talk to their doctor.
The CPS recommends that mothers exclusively breastfeed their babies until they are six months old. If for any reason the mother can't breastfeed and the child has a high risk of developing allergies, so-called “hypoallergenic” infant formula might be appropriate. The CPS still recommends that parents wait until their child is between 9 and 12 months old before they introduce whole cow’s milk, that they avoid giving their child egg whites before the age of one, and in cases where there is a family history of allergies, that they wait until the child is three years old before introducing peanuts, other nuts and seafood.