European researchers have looked at the feeding practices of parents in Austria, Finland, Greece, Germany and Switzerland to measure the diversity of diets in children during their early years of development.
These diets were compared to diagnosis of asthma, food allergies and allergic rhinitis. It's the first time a study of this type has shown a correlation between increased food exposure and lower rates of allergies.
The study began with expectant mothers and followed them through birth to 12 months. The new mothers kept a monthly diary of food given to their children from the age of 3 months to 1 year.
Questionnaires and blood tests were conducted after that point until the children were six years of age. A "food diversity score" was assigned to each child according to the number of different foods fed in that first year. This score was then compared to rates of allergy diagnosis. 865 infants were included in the study.
Results showed that the higher the child's food diversity score, the lower the risk of allergic diseases. In particular, milk and fish were seen to correspond to lower rates of asthma and food allergies respectively.
In addition, the children who had lower food diversity scores were seen to have higher levels of the antibody IgE, known to be associated with heavy immune responses which are what define an allergy.
Finally, the study also found that children with two allergic parents were more likely to have allergies, but at the same time, they were also more likely to have a lower food diversity score. This makes genetic causes inconclusive.