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

BACKGROUND

Soluble-fiber beta-glucan derived from oats can reduce cardiovascular disease (CVD) risk through reductions in total and LDL cholesterol. Barley-derived beta-glucan may also improve serum cholesterol, but large quantities are required for clinical significance.

OBJECTIVE

This trial investigated whether a beta-glucan-enriched form of barley can favorably modify cholesterol and other markers of CVD and diabetes risk.

DESIGN

Eighteen mildly hyperlipidemic ( +/- 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 beta-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 (Delta) in total (Delta = -0.08 mmol/L, -1.3%), LDL (Delta = -0.15 mmol/L, -3.8%), or HDL (Delta = 0 mmol/L) cholesterol or in triacylglycerol (Delta = 0.18 mmol/L), fasting glucose (Delta = -0.05 mmol/L), or postprandial glucose when analyzed between treatments (P > 0.05; ANOVA).

CONCLUSION

The effect of beta-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.