Background & aims: A recent study reported that isohumulones, the bitter component of beer, activate peroxisome proliferator-activated receptor alpha (PPARalpha) and PPARgamma in vitro and decrease plasma glucose and lipid levels in diabetic mice. This study was to investigate the efficacy and safety of isohumulones for subjects with prediabetes.
Methods: Ninety-four subjects with prediabetes were randomly divided into four groups. A 12-week double-blind dose-finding study was performed in which subjects ingested placebo capsules or test capsules containing 16 mg, 32 mg or 48 mg of isohumulones per day.
Result: After treatment, fasting blood glucose was decreased in the 32 mg and 48 mg groups after 4 weeks, but did not change in the placebo group. HbA1c was also significantly decreased after 4 weeks in the 16 mg group and after 8 weeks in the 32 mg and 48 mg groups. Body mass index (BMI) was significantly decreased in the 48 mg group as compared with the placebo group at 12 weeks. The decrease in total fat area was also significantly greater in the 48 mg group than in the placebo group at 12 weeks.
Conclusion: The present study suggests that ingestion of isohumulones has beneficial effects in diabetes and obesity.