Nutrition and children's respiratory health in Guangzhou, China

Objective: To investigate the role of nutrition in children's respiratory health in subjects participating in a study on air pollution and respiratory health.

Study design: Cross-sectional survey.

Methods: The relationships between consumption of fresh fruit, vegetables and milk and pulmonary function (forced expiratory volume in 1 s, FEV1) and respiratory symptoms (phlegm with cold, phlegm without cold, cough with cold, and cough without cold) were examined in 2228 children (age 10.07 ± 0.86 years) in Guangzhou, China.

Results: A positive association was found between consumption of leafy vegetables and lung function in children. Subjects with the highest consumption of leafy vegetables had significant higher FEV1 values than subjects who ate leafy vegetables less than once per week (1.68 l vs 1.56 l; P = 0.047). Children with high consumption of fresh fruit and milk had higher lung function values than children with low consumption, although the differences were not statistically significant. Milk consumption was a protective factor for phlegm with cold, cough with cold, and cough without cold [odds ratio (OR) 0.62, 95% confidence interval (CI) 0.39–0.97; OR 0.53, 95% CI 0.36–0.79; OR 0.43, 95% CI 0.21–0.92, respectively, in the highest intake group]. Consumption of vegetables was a protective factor for cough with cold (P for trend = 0.003) and cough without cold (P for trend = 0.028). Consumption of fresh fruit was marginally associated with reduced prevalence of respiratory symptoms.

Conclusions: This study suggests that dietary nutrients are important protective factors for children's respiratory health. Following-up these children may provide more evidence to confirm these associations.