Fruit intake reduces the onset of respiratory allergic symptoms in schoolchildren
Because the prevalence of allergic diseases has recently been on the rise,1 early intervention strategies to prevent the onset of allergic symptoms should be considered. Several previous studies have shown that dietary pattern is associated with allergy prevention. For example, the Mediterranean diet, which involves relatively high consumption of fruit, vegetables, beans, and fish, and relatively low consumption of meat and dairy products, has been shown to help prevent asthmatic symptoms in children.2 The cause of this effect is considered to be the abundance of antioxidants, such as vitamins C and E, polyphenols, and carotenoid, as well as high n–3 and low n–6 unsaturated fatty acids, in such diets,4 as diets high in antioxidants have been shown to prevent allergy symptoms through their anti‐inflammatory effects.5 In addition, such diets have been reported to affect the intestinal microflora, which may indirectly lead to the suppression of allergic diseases.6 Several reports have shown that dietary patterns, as opposed to individual ingredients, are important for allergy prevention.7 Dietary intervention might therefore be important from early infancy or even during pregnancy.10
Only a few previous investigations have been conducted using longitudinal surveys,5 and a causal relationship between diet and allergy has yet to be confirmed. Moreover, several studies have reported finding no allergy‐preventive effects as a result of diet.15 To prospectively investigate the association between diet and allergic symptoms, we used data collected in our recently performed 4‐year longitudinal survey investigating the effect of various lifestyle factors on allergic symptoms, the Lifestyle and Allergy among Kids in Elementary school (LAKE) study17 to examine the effects of four supposedly allergy‐suppressive foods2—fruits, vegetables, fish, and beans—on allergic symptoms in schoolchildren.