Black tea may serve as a promising antidiabetic agent for glycemic control.
The consumption of black tea significantly reduced incremental blood glucose following sucrose intake, according to a study published in theAsia Pacific Journal of Clinical Nutrition.
For the study, the investigators sought to examine the effect of black tea consumption on postprandial blood glucose and insulin response following sucrose loading in normal and prediabetes individuals, since few clinical studies have been done.
Initially the investigators recruited 72 participants aged 20 to 60 years from the Department of Nutrition, Faculty of Public Health, Mahidol University. Inclusion criteria for the normal group was fasting blood glucose level of 70 to 100 mg/dL, and the prediabetic group was 100 to 125 mg/dL.
In the end, a total of 24 subjects were randomly assigned into 2 major groups: normal and prediabetic (13 participants and 11 participants, respectively).
For the double-blind, placebo-controlled crossover study, the participants were randomized to receive either a drink containing low dose (110 mg black tea polymerized polyphenol [BTPP]), a high dose (220 mg BTPP), or a placebo (0 g BBTP). The drinks were consumed with a 50 g sucrose solution (200 mL), which was prepared separately on each study day.
Blood samples were collected at 0, 30, 60, 90, and 120 minutes from commencement of drink ingestion to measuring of blood glucose and insulin levels.
The results of the study showed that following the ingestion of sucrose, the black tea drink containing low- and high-dose BTPP significantly decreased incremental blood glucose area under the curve (AUC) compared with placebo in the normal andprediabeticgroups.
Furthermore, there were no statistically significant difference of changes in insulin levels between the placebo and black tea groups.
Adverse events were found to be rare and had no significant differences between the placebo, low-dose, and high-dose BTPP groups.
Overall, the findings demonstrated the ability of black tea consumption to decrease postprandial blood glucose after sucrose intake in both normal and prediabetes subjects.
“[The findings suggest] that black tea may be a promising antidiabetic agent for glycemic control,” the authors concluded.