A cross-sectional study of food group intake and C-reactive protein among children

Background: C-reactive protein (CRP), a marker of sub-clinical inflammation, is a predictor of future cardiovascular diseases. Dietary habits affect serum CRP level however the relationship between consumption of individual food groups and CRP levels has not been established. Methods: This study was designed to explore the relation between food intake and CRP levels in children using data from the cross-sectional 1999-2002 National Health and Nutrition Examination Surveys. CRP level was classified as low, average or high (<1.0, 1.0-3.0, and >3.0 mg/L, respectively). Adjusted mean daily intakes of dairy, grains, fruit, vegetables, and meat/other proteins in each CRP category were estimated using multivariate analysis of covariance modeling. The effect modification by age (5-11 years vs. 12-16 years), gender and race/ethnicity was explored. We examined whether total or central body fat (using BMI Z-scores and waist circumference) explained any of the observed associations. Results: A total of 4,010 children and adolescents had complete information on diet, CRP and all covariates of interest and were included in the analyses. Individuals with high CRP levels had significantly lower intake of grains (p < 0.001) and vegetables (p = 0.0002). Selected individual food subgroups (e.g., fluid milk and "citrus, melon and berry" consumption) were more strongly associated with lower CRP than were their respective major food groups. Consumption of meat/other proteins did not influence CRP levels. The addition of body composition variables to the models attenuated the results for all food groups to varying degrees. Conclusion: Children and adolescents with higher CRP levels had significantly lower intakes of grains and vegetables. The associations between selected childhood dietary patterns and CRP levels seem largely mediated through effects on body composition.