What Is the Relationship Between Dairy Intake and Blood Pressure in Black and White Children and Adolescents Enrolled in a Weight Management Program?

BACKGROUND: The DASH (Dietary Approaches to Stop Hypertension) clinical trials and other studies have demonstrated a relationship between diet and cardiovascular outcomes in adults, yet little is known of this relationship in children. Childhood obesity has reached epidemic proportions in the United States, with similar increases in hypertension among this population. The purpose of our study was to examine the association between dairy intake and blood pressure (BP) in a cohort of children and adolescents (aged 4-17 years) enrolled in a weight management program. METHODS AND RESULTS: Dietary intake was assessed using the Block Kids 2004 food frequency questionnaire in a cross-sectional sample of participants enrolled in the Pediatric Metabolic Syndrome Study at the Children's Hospital (Charleston, SC). BP and other anthropometrics were obtained at baseline. Only children with complete baseline data and food frequency questionnaires were included in this analysis (n=117). Associations between food group/nutrient intake and BP were examined across race and sex using ANOVA and Pearson correlations. Linear regression models were controlled for body mass index and age. In the total sample, a significant inverse relationship was found between the intake of dairy and systolic BP (r=-0.24, P=0.009). The effect of dairy on systolic BP, however, differed by race. We observed a decrease of 11.2 mm Hg for each serving of dairy consumed by white children, and no decrease in systolic BP in black children (P=0.001 for the race-dairy serving interaction). CONCLUSIONS: Nutrition professionals must consider nonnutrition factors contributing to childhood hypertension, as current dietary recommendations appear to have differential outcomes across races.