Several studies have examined the effects of diet on respiratory health of children and adults, but few have focused on adolescents.1,–3 The accrued data indicate that a diet rich in fruit, antioxidants, and omega-3 fatty acids may contribute to optimal respiratory health. Poor dietary habits and rapid physical growth might make adolescents particularly vulnerable to the effects of low dietary nutrient intake on lung function and pulmonary symptoms. Investigators from Harvard Medical School, the National Health Research Laboratory, and the Environmental Protection Agency in the US and Safe Environments in Canada explored such associations in a cohort of 2,112 12th-grade students (age range 16–19 years) from the US and Canada during the 1998–1999 school year (the Teen Lung Study).
Students completed a standardized respiratory questionnaire and underwent pulmonary function testing. Each student also completed a food frequency questionnaire, which included vitamin supplements and focused on antioxidant foods (fruits, vegetables), micronutrients (vitamins C, E, and beta-carotene), and nutrients with effects on cell function and inflammatory processes (retinol and n−3 fatty acids). Exclusion criteria included a history of a chest operation, heart disease, or a debilitating health condition that limited physical activity, and those reporting extremes of caloric intake. Linear mixed models were used to evaluate the associations between dietary factors and pulmonary function. Associations between dietary intakes and respiratory symptoms were analyzed using logistic regression.
Of the 2,112 students for whom complete data were available, 89% were white, 45% were males, 30% were overweight, 24% were smokers, and 11% consumed a daily multivitamin. (3.9L Low dietary fruit intake was associated with a lower FEV1 vs 3.96L, −1.3% difference from those with higher fruit intake; 95% CI, −2.4 to −0.2% difference) and increased odds of chronic bronchitic symptoms (OR, 1.36; 95% CI, 1.03–1.73) compared with higher intake. Low dietary n−3 fatty acid intake was associated with a similar significant increase in odds of chronic bronchitic symptoms, wheezing, and asthma compared with higher intake. Smokers with lower dietary vitamin C intake had higher ORs for respiratory symptoms compared with smokers with higher intake.
The authors conclude that adolescents with the lowest intakes of antioxidants and anti-inflammatory micronutrients had lower pulmonary function and increased respiratory symptoms, especially among smokers. They recommend promoting fruit and fish consumption in addition to vitamin supplementation as potentially important adjuncts to protect respiratory health in adolescents, especially among those who smoke.
Dr. Dubik has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. Dr. Barton has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
The results of the present study are modest but statistically significant and consistent with previous observations,1,–4 including the reported benefit of...