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

Abstract

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.

Figure 1. Dietary pattern, IL-17F plasma levels, and proportion of children with current asthma (n=578)

† Individuals who had high consumption of vegetables or grains were assigned a score of +1 for each. Individuals who had higher consumption of dairy products or sweets were assigned a score of −1 for each. The overall dietary pattern is represented by the sum of the four individual scores (range −2 for the most “unhealthy diet” to +2 for the most “healthy diet”) *P-trend < 0.01. **P-trend = 0.01