Randomized controlled crossover study of the effect of a highly β-glucan-enriched barley on cardiovascular disease risk factors in mildly hypercholesterolemic men

Abstract

Background: Soluble-fiber β-glucan derived from oats can reduce cardiovascular disease (CVD) risk through reductions in total and LDL cholesterol. Barley-derived β-glucan may also improve serum cholesterol, but large quantities are required for clinical significance. Objective: This trial investigated whether a β-glucan-enriched form of barley can favorably modify cholesterol and other markers of CVD and diabetes risk. Design: Eighteen mildly hyperlipidemic (x̄ ± SD: 4.0 ± 0.6 mmol LDL cholesterol/L) men with a mean (± SD) body mass index (in kg/m 2) of 27.4 ± 4.6 were randomly assigned in this single-blind, 2 X 4-wk trial to either the treatment arm [8.1-11.9 g β-glucan/d (scaled to body weight)] or the control arm (isoenergetic dose of 6.5-9.2 g glucose/d). After a washout period of 4 wk, dietary regimens were crossed over. The trial took place in a long-stay metabolic facility, and all foods were provided (38% of energy from fat). Fasted blood samples were collected on days 0, 1, 7, 14, 21, 28, and 29 in both study arms. An oral-glucose-tolerance test was carried out on days 0 and 29. Results: There was no significant change (Δ) in total (Δ = -0.08 mmol/L, -1.3%), LDL (Δ = -0.15 mmol/L, -3.8%), or HDL (Δ = 0 mmol/L) cholesterol or in triacylglycerol (Δ = 0.18 mmol/L), fasting glucose (Δ = -0.05 mmol/L), or post-prandial glucose when analyzed between treatments (P > 0.05; ANOVA). Conclusion: The effect of β-glucan-enriched barley on lipid profile was highly variable between subjects, and there was no evidence of a clinically significant improvement in CVD risk across this group of mildly hyperlipidemic men.