Lawrence also reports that the incidence of allergies has increased tenfold over the last 20 years. The increase may be due to better recognition of allergic symptoms as well as the increased incidence of exposure to known allergens. Increased longevity has helped us recognize the connection between allergy and many chronic illnesses. Narrowing food choices in this way increases exposure to these foods and predisposes people to allergies. The earlier and more often a food is ingested, the greater likelihood it has of becoming an allergen.
Babies tend to be most allergic to the first foods they have been offered.
A study by Saarinen and Kajosaari showed that breastfeeding reduces food allergies-at least through adolescence. Protection from allergic disorders and resistance to infection are the most often cited immunologic benefits of breastfeeding. Symptoms of cow's milk allergies are up to seven times more common in babies who are fed manufactured baby milk instead of human milk, according to Lawrence. By about six weeks of age, Peyer's Patches in the intestines begin operating, assisting baby's immunities by producing immunoglobulins. Mature milk continues this protective help.