Dietary fibre intake is inversely associated with carotid intima-media thickness: a cross-sectional assessment in the PREDIMED study

Objective: To assess the association between the intake of dietary fibre and carotid intima-media thickness (IMT) in a Mediterranean population at high cardiovascular risk. Methods: Baseline cross-sectional assessment of 457 men and women (average age 67 years) from two different Spanish centres of the PREDIMED trial. A previously validated food frequency questionnaire (137 food items) was administered by trained dieticians in a face-to-face interview. Mean common carotid IMT was measured using B-mode ultrasound imaging of the right and left carotid arteries by four certified sonographers who used a common protocol. Anthropometric and blood pressure measurements were performed and samples of fasting blood were obtained. Participants were categorized into four groups (roughly quartiles: <= 21; > 21 to <= 25; > 25 to <= 31 and > 31 g/day) of energy-adjusted intake of dietary fibre. Multiple linear regression models were used to adjust for age, sex, centre, smoking, body mass index, diabetes, blood pressure, lipid levels and statin use. Results: In the crude analyses, energy-adjusted fibre intake showed a significant inverse correlation with IMT (r = -0.27, P < 0.001). In multivariate analyses, a modest, though statistically significant (P = 0.03) inverse association between energy-adjusted fibre intake and IMT was also found. The multivariate-adjusted difference in average IMT was -0.051 mm (95% confidence interval: -0.094 to -0.009, P = 0.02) for participants whose intake was > 35 g/day, (n = 47) when compared with those whose intake was < 25 g/day (n = 224). Conclusions: Our results suggest that high fibre intake is inversely associated with carotid atherosclerosis. European Journal of Clinical Nutrition (2009) 63, 1213-1219; doi:10.1038/ejcn.2009.45; published online 24 June 2009