Fruits and vegetables do not seem to offer protection against allergic disease if diet modifications are considered
Recent studies have suggested that a diet that includes fruits and vegetables can have a protective effect against allergic disease in children. Fruits and vegetables are rich sources of antioxidants which are thought to reduce airway inflammation. However, some fruits, like apples and pears, or vegetables such as carrots contain proteins that can cross-react with major pollen allergens. In children allergic to these pollens, this can result in an allergic reaction; therefore, allergic children may follow a modified diet to avoid certain fruits and vegetables. This could confuse research findings, falsely suggesting that diets with fewer fruits and vegetables result in more allergic disease.
In a study published in the February 2011 issue of The Journal of Allergy and Clinical Immunology (JACI), Rosenlund et al investigated the associations between fruit or vegetable consumption and allergic disease in 8-year-old Swedish children. The authors collected information on the children’s fruit and vegetable consumption, their allergy and asthma symptoms and IgE antibodies in their blood to various food and airborne pollen allergens.
The authors observed an inverse relationship between total fruit consumption and rhinitis, while no association was observed for total vegetable intake. Moreover, when individual fruits and vegetables were analyzed, apples/pears, carrots and legumes showed protective effects on allergic disease. When the researchers excluded children who reported food-related allergic symptoms from their analysis, most of the observed inverse associations became non-significant.
The authors’ findings suggest not only that fruit and vegetable consumption could have a protective effect against allergic disease, but also that in this Swedish population, disease-related modification of diet contributed to this effect. Future studies should investigate fruit and vegetable consumption in other geographical areas, and disease-related modification of dietary consumption should be taken into account when studying fruit and vegetable intake in relation to allergic diseases.
The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.