Diet, interleukin-17, and childhood asthma in Puerto Ricans.

BACKGROUND

Dietary patterns might influence the pathogenesis of asthma in Puerto Ricans, the ethnic group most affected by this disease in the United States.

OBJECTIVE

To examine the association among diet, T-helper cell type 17 cytokines, and asthma in Puerto Rican children.

METHODS

As part of a case-control study of 678 Puerto Rican children 6 to 14 years old in San Juan, participants completed a 75-item questionnaire on the child's food consumption in the prior week. Foods were aggregated into 7 groups: fruits, vegetables, grains, protein foods, dairy, fats, and sweets. Logistic regression was used to evaluate consumption frequency of each group, plasma T-helper cell type 17 cytokine levels, and asthma. Based on this analysis, a food score (range -2 [unhealthy diet: high consumption of dairy products and sweets, low consumption of vegetables and grains] to +2 [healthy diet: high consumption of grains and vegetables, low consumption of dairy and sweets]) was created to identify dietary patterns.

RESULTS

High consumption of grains was associated with lower odds of asthma (adjusted odds ratio [aOR] 0.52, 95% confidence interval [CI] 0.33-0.82), whereas frequent consumption of dairy products (aOR 1.93, 95% CI 1.32-2.84) or sweets (aOR 1.82, 95% CI 1.08-2.72) was associated with higher odds of asthma. A healthier diet (each 1-point increment in food score) was associated with lower levels of interleukin-17F (β = -1.48 pg/mL, 95% CI -1.78 to -1.20) and with 36% decreased odds of asthma (aOR 0.64, 95% CI 0.53-0.77).

CONCLUSION

A healthy diet, with frequent consumption of vegetables and grains and low consumption of dairy products and sweets, was associated with lower levels of interleulin-17F and decreased odds of childhood asthma in Puerto Ricans.