The association of fruits, vegetables, antioxidant vitamins and fibre intake with high-sensitivity C-reactive protein: sex and body mass index interactions

Objective: To study the associations of fruits, vegetables, antioxidant vitamins and fibre intake with high-sensitivity C-reactive protein (hs-CRP). Existing literature on these associations is scarce and has rendered conflicting results. Methods: Cross-sectional study of 1060 individuals (675 women, 385 men), representative of the non-institutionalized population, aged >= 18 years, in Porto, Portugal (70% participation rate). Diet over the previous year was assessed with a validated food frequency questionnaire. Associations between diet and hs-CRP (categorized into <1, 1-3, >3 to <= 10 mg/l) were obtained from ordinal logistic regression models (odds ratio, 95% confidence intervals-OR, 95% CI) adjusted for sociodemographic and behavioural variables. Results: In normal weight men (body mass index (BMI) <25.0 kg/m(2)), for each 100 g increase in fruit and vegetable intake, there was 30% less probability of changing of hs-CRP category (no risk to moderate risk, or moderate to high risk). Protective associations were also observed between hs-CRP and fruits (OR = 0.73, 95% CI 0.56-0.96 per 100 g/day), vegetables (OR = 0.55, 95% CI 0.35-0.86 per 100 g/day), vitamin C (OR = 0.34, 95% CI 0.14-0.80 per 10 mg/day) and vitamin E (OR = 0.14, 95% CI 0.02-0.88 per 1000 retinol equivalents per day). Overall, associations tended to be weaker in overweight participants. In men (BMI >= 25.0 kg/m(2)), fibre was also negatively associated with hs-CRP. In women, no significant associations were found between dietary variables and hs-CRP. A significant modification effect of the evaluated associations was found by sex for fruits and vegetables, vitamin C and fibre, but not by BMI. Conclusion: Intake of fruits and vegetables, vitamin C, E and fibre were negatively associated with hs-CRP in men. European Journal of Clinical Nutrition (2009) 63, 1345-1352; doi: 10.1038/ejcn. 2009.61; published online 22 July 2009