ABSTRACT
The prevalence of allergies and asthma varies greatly in different countries. The International Study of Asthma and Allergies in Childhood assessed the prevalence of symptoms of asthma, rhinitis and eczema in 463,801 children ages 13–14 years from 155 centers in 56. It was found that the prevalence of asthma in these children varied from 1.6% in Indonesia to 36.8% at one center in the United Kingdom. In a systematic review of 14 studies including 108,321 women and off-spring, followed from 14 months to 16 years, obesity was associated with an increased risk for present asthma or wheeze with a dose response. Low birth weight and neonatal hyperbilirubinemia have both been associated with an increased risk for asthma. Delivery by Caesarean section is a risk for asthma. A questionnaire-based evaluation of 1,784 school children found that following a Mediterranean diet was associated with a reduced risk of wheeze at 4 years.
