Diet plays key role in severe childhood allergic disorders
medwireNews: Study findings suggest that children and adolescents who eat fast food three times a week or more have a greater risk for severe asthma, rhinoconjunctivitis, and eczema than those who do not.
Conversely, consumption of fruit three times a week or more seemed to have a protective effect against severe asthma.
In total, 319,196 adolescents aged 13-14 years from 51 countries and 181,631 children aged 6-7 years from 31 countries participated in phase three of the International Study of Asthma and Allergies in Childhood.
Questionnaires on the prevalence of asthma, rhinoconjunctivitis, and eczema symptoms
and types and frequency of food intake over the past year were completed by the adolescents and the parents or guardians of the younger children.
Philippa Ellwood (The University of Auckland, New Zealand) and team found that the risk for symptoms of severe asthma in adolescents and children who ate fruit three times per week or more was reduced by a respective 11% and 14% compared with those who ate less than one serving of fruit a week. The risk for current wheeze was also significantly reduced.
However, fruit consumption three times a week or more did not significantly reduce the risk for severe rhinoconjunctivitis or eczema in adolescents, although there was a significant 44% and 22% reduction in risk for symptoms of these conditions in children. High egg, meat, and milk consumption also showed significant protective effects against these symptoms although to a lesser extent.
By contrast, the risk for severe asthma was increased by 39% and 27% in adolescents and children, respectively, who ate fast food three times a week or more, as well as smaller but still significantly increased risk for current wheeze, compared with those who ate less than one serving per week.
Adolescents who ate fast food three times weekly or more also had a 73% and 70% increased risk for severe rhinoconjunctivitis and eczema, respectively, compared with those who ate fast food less than once a week, and children who consumed this amount had corresponding risk increases of 32% and 30% compared with those who ate less than one serving per week.
High butter, margarine, and pasta intake were also associated with increased risks for all three conditions, but to a lesser extent.
"The positive association observed here between fast food intake and the symptom prevalence of asthma, rhinoconjunctivitis and eczema in adolescents and children deserves further exploration, particularly in view of the fact that fast food is increasing in popularity around the world," write the authors in Thorax.
"Equally, the protective association between fruit and vegetables and the three conditions should be further explored at country and regional levels."
They note that "the positive association with severe disease suggests that fast foods are a predictor of disease severity rather than disease occurrence," but concede that "it is difficult to separate out the two in this study."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Helen Albert, Senior medwireNews Reporter