There is no clear evidence that allergen avoidance or delayed introduction of foods has any beneficial effect. A recent study was conducted to assess relationship between food diversity and other allergic diseases. The study included 856 children and included information on feeding during the first year of life from parental diaries. Follow-up questionnaires were used to collect data on the development of asthma, allergic rhinitis, food allergies and atopy up to 6 years of age. Based on a score consisting of six food items, children with a more diverse diet during the first year of life were at lower risk of allergic diseases. This score was inversely associated with asthma risk and food allergy.
There was an increased expression of forkhead box protein 3, a transcription factor for regulatory T cells which led to a decreased expression of IgE. There is a protective effect from a Th1/Th2 balance shift from the induction of regulatory T cells.