A diet rich in oat bran improves blood lipids and hemostatic factors, and reduces apparent energy digestibility in young healthy volunteers

Abstract

Background/Objectives: Oat bran shows cholesterol-lowering properties, but its effects on other cardiovascular risk markers are less frequently investigated. This study examined the effects of oat bran on blood lipids, hemostatic factors and energy utilization. Subjects/Methods: A double-blind, randomized crossover study in 24 adults (age 25.2±2.7 years; body mass index: 24.9±2.9 kg/m 2), who completed two 2-week dietary intervention periods: low-fiber diet (control) or an oat bran (control +102 g oat bran/day) diet. Fasting blood samples were drawn before and after each period, and 3-day fecal samples were collected during the last week of each period. Results: Total cholesterol decreased by 14% during the oat bran period compared with 4% during the control period (P<0.001). Non-high-density lipoprotein (HDL) cholesterol decreased by 16% in the oat bran period compared with 3% in the control period (P<0.01), as did total triacylglycerol (21 vs 10%, P<0.05) and very-low-density lipoprotein triacylglycerol 33 vs 9%, P<0.01). Plasminogen activator inhibitor-1 (PAI-1) and factor VII (fVII) levels decreased more during consumption of oat bran compared with the control period (PAI-1: 30 vs 2.3%, P<0.01; fVII: 15 vs 7.6%, <0.001). Fecal volume and dry matter were greater when consuming the oat bran diet compared with the control (P<0.001), and energy excretion was increased by 37% (1014 vs 638 kJ/day, P<0.001); however, changes in body weight did not differ (oat bran: -0.3±0.5 kg; control: 0.0±0.7 kg). Conclusions: Addition of oat bran (6 g soluble fiber/day) to a low-fiber diet lowered total and non-HDL cholesterol, as well as hemostatic factors, and may affect energy balance through reduced energy utilization. © 2011 Macmillan Publishers Limited All rights reserved.