Background: The effects of the DASH (Dietary Approaches to Stop Hypertension) diet on inflammation in childhood metabolic syndrome (MetS) have still to be identified.
Objective: To examine the effects of the DASH diet on markers of systemic inflammation in adolescents with MetS.
Methods: In this randomized, cross-over clinical trial, 60 postpubescent girls with MetS were randomly assigned to receive either the DASH diet menu cycles or usual dietary advice (UDA) for 6 weeks. After a 4-week washout period, participants were crossed over to the alternate arm. The DASH diet was designed to maintain the current body weight. This diet contained high amounts of fruit, vegetables and low-fat dairy products and was low in saturated fats and cholesterol. UDA consisted of general oral advice and written information about healthy food choices based on the Healthy Eating Plate. Compliance to the DASH diet was assessed through quantification of plasma vitamin C levels. Fasting venous blood samples were taken 4 times from each participant: at baseline and at the end of each study arm. Circulating levels of biomarkers of systemic inflammation were quantified according to standard protocols.
Results: Mean (SD) age and weight of participants was 14.2 years (1.7) and 69 kg (14.5), respectively. Serum vitamin C levels tended to increase during the DASH phase compared with the UDA phase (16.8 ± 12.9 vs. -13.8 ± 9.7 ng/dl, respectively, p = 0.06) indicating a relatively good compliance to the DASH diet. Adherence to the DASH diet, compared to the UDA, had a significant effect on serum high-sensitivity C-reactive protein levels (p = 0.002). This effect remained significant even after adjustment for weight changes and after further controlling for changes in lipid profiles. We did not observe any significant effect of intervention on levels of serum tumor necrosis factor-alpha, interleukin (IL)-2, IL-6 and adiponectin, in either the crude or adjusted models. There were no significant group*time interactions for any dependent variable, except for IL-6; this was close to the significant level.
Conclusion: In summary, consumption of the DASH eating pattern for 6 weeks may reduce circulating levels of hs-CRP among adolescents with MetS. Other inflammatory markers were not affected by the DASH diet.