Safety evaluation of a beverage containing mulberry leaf extract

Mulberry leaf extract (MLE) has known as inhibits elevated postprandial blood glucose level in human. Then, we conducted a randomized, double-blind placebo-controlled parallel-group trial to evaluate safety when a green tea containing MLE is consumed 3 times a day, every day for 4 weeks. The participants (n = 48) were randomly allocated into 2 groups, an MLE beverage group and a control beverage group. The subjects were instructed to drink either a 500 mL green tea containing 550 mg MLE or a 500 mL green tea not containing MLE, 3 times a day, every day, for 4 weeks. No adverse reactions were observed over the 4 weeks trial, and no difference in the incidence of adverse events between the groups. These findings demonstrate that the consumption of a green tea containing 550 mg MLE 3 times a day for 4 weeks is safe for healthy adults.