Background: Limited data are available relating intake of fruits and vegetables to inflammatory markers and risk of metabolic syndrome. The aim of this study was to evaluate the relationship between fruits and vegetables intake and C-reactive protein (CRP) and the prevalence of the metabolic syndrome.

Methods: Fruits and vegetables intake were assessed using a validated semi-quantitative food frequency questionnaire in a cross-sectional study of 486 Tehranian female teachers aged 40-60 y. Anthropometric measurements were done and blood pressure was assessed according to standard methods. Fasting blood samples were taken for biochemical measurements. The metabolic syndrome was defined according to Adult Treatment Panel III guidelines.

Results: The reported mean daily intake of fruits and vegetables were 228±79 and 186±88 g/d respectively. Both fruits and vegetables intake were inversely associated with plasma CRP concentrations. After statistically controlling for age, BMI and waist circumference, mean plasma concentrations of CRP across increasing quintile categories of fruits were 1.94, 1.79, 1.65, 1.61 and 1.56 mg/L respectively (P for trend <0.01) and of vegetables were 2.03, 1.82, 1.58, 1.52 and 1.47 mg/L respectively (P for trend<0.01). These inverse associations remained significant after additional control for other potential confounding variables and dietary factors. After controlling for potential confounders individuals in the highest quintile of fruits intake had 34% (95% CI: 20%-46%) lower and those in the highest quintile of vegetables intake had 30% (95% CI: 16%-39%) lower chance of having the metabolic syndrome compared to those in the lowest quintiles.

Conclusion: In this study higher intake of fruits and vegetables were associated with lower risk of metabolic syndrome; part of this association may be mediated through CRP. These findings support current dietary recommendations to increase the intake of fruits and vegetables as a primary preventive measure against cardiovascular disease.