Effects of high β-glucan barley on visceral fat obesity in Japanese individuals: A randomized, double-blind study.

Objective: The aim of this study was to investigate whether a diet in which high β-glucan barley was substituted for rice would reduce visceral fat obesity in Japanese individuals.

Methods: A randomized, double-blind, placebo-controlled intervention study was conducted with 100 Japanese individuals with waist circumference (WC) ≥85 cm for men or ≥90 cm for women and body mass index (BMI) ≥24 kg/m. Participants were randomly assigned to consume a mixture of rice and either high β-glucan barley (test group, 4.4 g/d) or β-glucan-free barley (placebo group) for 12 wk. Blood samples and computed tomography scans were obtained before and after the trial.

Results: Both groups showed decreases in body weight and BMI, and these changes were significantly greater in the test group. WC and visceral fat area (VFA) significantly decreased in both groups (VFA: -10.7 cm in the test group; -6.8 cm in the placebo group). These changes did not differ significantly between the groups. However, a subgroup analysis of participants with VFA ≥100 cm showed a significant decrease in the test group, and this decrease was significantly greater than in the placebo group.

Conclusions: The intake of high β-glucan barley led to significant and safe reductions in VFA, body weight, BMI, and WC in individuals with visceral fat obesity with VFA ≥100 cm. Barley high in β-glucan may contribute to preventing visceral fat obesity.