薬理と治療

Abstract

Objectives We developed a black tea beverage supplemented with indigestible dextrin. In this study, we investigated whether the beverage would suppress the postprandial elevation of blood glucose level of volunteers. We also evaluated the safety of the beverage. Methods Human trial 1. We conducted a double−blinded crossover trial. 24 volunteers （48.0±13.3 years old）ingested a test meal and a 350 mL of black tea beverage supplemented with 5 g of indigestible dextrin or a placebo. The blood glucose level and insulin level were measured after meal. Human trial 2. We conducted two open−label trials to evaluate safety of the beverage. For each trial, 16 volunteers, including four volunteers with impaired glucose regulation（110≦FGP＜126 and／or 5.8≦HbA1C＜6.5）, were enrolled（45.4±15.7 and 44.6±15.5 years old, respectively）. In the first trial, volunteers consumed the test beverage three times a day for 12 weeks. In the second trial, volunteers consumed another test beverage supplemented with an excess amount of indigestible dextrin three times a day for four weeks. They had health interviews, blood tests and urine tests during the test period. Results Human trial 1. Concurrent ingestion of the test beverage with the test meal significantly lowered the blood glucose level and insulin level at 30 minutes after meal compared to concurrent ingestion of the placebo. Human trial 2. No harmful effect caused by the test beverages was observed throughout the study periods. Conclusions The data obtained through these trials suggested that the black tea beverage supplemented with indigestible dextrin suppresses the elevation of the postprandial blood glucose level and that the beverage is safe when it is consumed continuously at the recommended dose.（Jpn Pharmacol Ther 2008；36：613−22）KEY WORDS Indigestible dextrin, Black tea, Blood glucose level, Safety