Effect of Powdered Beverages Containing Pu-erh Tea Extract on Postprandial Blood Glucose Levels

Objective: The current study aimed to examine the effect of a single ingestion of a beverage containing Pu-erh tea extract (Pu-erh tea polyphenol 32.48mg, eq. gallic acid) on postprandial blood glucose levels through a comparison using a crossover test. Method: A total of 20 participants, of which 10 were men and 10 were women, aged between 29 and 64 years were instructed to ingest beverages containing Pu-erh tea extract or placebo beverages at the same time as load food (in addition to cooked rice). Their blood glucose levels were measured before and 30, 60, 90, and 120 min after ingestion. Results: In phases I and II of the trial, three participants who had large differences in the quantity of the ingested food on the day before the trial were removed from the study. Finally, the analysis was conducted on 17 participants. Result showed that the group who ingested the beverage containing Pu-erh tea extract had significantly lower blood glucose levels than the group who consumed the placebo beverage 60, 90, and 120 min after ingestion. In terms of the amount of variation before ingestion, the group who ingested beverages with Pu-erh tea extracts had significantly lower blood glucose levels than the group who consumed the placebo beverage 60, 90, and 120 min after ingestion. In terms of area under the curve (AUC) and increase in the area under the curve (IAUC) for blood glucose levels with some variations, the time it took for the participants to consume the trial beverage compared with the placebo beverage was significantl lower. Conclusion: Beverages containing Pu-erh tea extract were found to be effective in suppressing the increase in postprandial blood glucose levels after being loaded with cooked rice. Keywords: Pu-erh tea, postprandial blood glucose, cooked rice, type 2 diabetes