Black Tea drinks with inulin and dextrin reduced postprandial plasma glucose fluctuations in patients with type 2 diabetes: an acute, randomized, placebo-controlled, single-blind crossover study.

Background: This study evaluated the effects of black tea drinks with inulin and dextrin (BTID) on postprandial plasma glucose (PG) in patients with type 2 diabetes mellitus (T2DM).

Methods: An acute, randomized, double-blind, placebo-controlled, crossover clinical trial was carried out on T2DM patients. The subjects were randomly assigned to groups consuming placebo black tea powder or BTID (identically packaged) followed by a mixed meal tolerance test (MMTT). Afterwards, individuals who initially consumed BTID were given the placebo and those who initially consumed the placebo were given BTID.

Results: A total of 35 patients were included in the study, and 32 completed the study. Compared to placebo, BTID significantly reduced the change in glycaemia at 30 min, 1, 2, and 3 h during the MMTT. In the analysis of PG fluctuations at 2 h during the MMTT, the proportion of patients with minor PG fluctuations (< 2.8 mmol/L) in the BTID group was 53.1%, significantly higher than the 28.1% in the placebo group. Binary logistic regression analysis revealed that the risk of significant PG fluctuations decreased by 65.5% after consuming BTID, with a corresponding odds ratio of 0.345 (P = 0.044, 95% CI 0.122-0.974). In addition, the areas under the curve for PG and insulin secretion after BTID administration were significantly smaller than that for placebo.

Conclusions: Compared to placebo, BTID significantly reduced the change in PG levels during the MMTT and decreased the risk of large PG fluctuations by 65.5%. These effects were associated to a significant reduction in postprandial insulin secretion and may help to improved insulin sensitivity and a lower β-cell burden.