scholarly journals Black tea decreases postprandial blood glucose levels in healthy humans and contains high-molecular-weight polyphenols that inhibit α-glucosidase and α-amylase in vitro: a randomized, double blind, placebo-controlled, crossover trial

2021 ◽  
Vol 11 (5) ◽  
pp. 222
Author(s):  
Yoshikazu Isono ◽  
Hisako Watanabe ◽  
Masafumi Kumada ◽  
Tsuyoshi Takara ◽  
Shin-ichiro Iio
Keyword(s):  
Molecular Weight ◽  
Blood Glucose ◽  
High Molecular Weight ◽  
Area Under The Curve ◽  
Black Tea ◽  
Postprandial Blood Glucose ◽  
Double Blind ◽  
Glucose Levels ◽  
Healthy Humans ◽  
Blood Glucose Levels

Background: To prevent diabetes, it is important to control postprandial glycemic levels. Studies have suggested that consuming black tea decreases the risk of type 2 diabetes; however, only a few studies have examined the effects of black tea on postprandial glycemic control after consuming starch-rich foods. In addition, the mechanism underlying the suppression of postprandial glucose levels remains unclear.Objective: To investigate the effects of black tea on postprandial blood glucose levels in healthy humans and to identify the components of black tea that inhibit digestive enzymes.Methods: The inhibitory activity of black tea on digestive enzymes was measured, and the inhibitory components were fractionated. Healthy Japanese adults ingested 200 ml of black tea, and its effect on postprandial blood glucose and insulin levels were investigated. Results: Black tea dose-dependently inhibited α-glucosidase, sucrase, and α-amylase activity. The major components responsible for this inhibition were high–molecular-weight polyphenols. The galloyl moieties present in these compounds play an important role in their inhibitory activities. Two randomized, double-blind, placebo-controlled, crossover studies of healthy human subjects (total n = 46) were conducted to investigate the effect of black tea on blood glucose and insulin levels. Combined data from the two studies showed that black tea ingestion (200 mL) after cooked rice intake (200 g) significantly reduced the incremental area under the curve of glucose (P =.024) and insulin (P =.014) compared to placebo drink.Conclusions: The high–molecular-weight polyphenols in black tea inhibited α-glucosidase, sucrase, and α-amylase activity in a dose-dependent manner. Furthermore, black tea ingestion after eating cooked rice significantly reduced the incremental area under the curve of glucose and insulin. These effects of black tea could be attributed to the inhibition of digestive enzymes by high–molecular-weight polyphenols containing galloyl groups.Keywords: black tea, blood glucose, α-glucosidase, α-amylase, polyphenol

scholarly journals The Possibility of Suppression of Increased Postprandial Blood Glucose Levels by Gamma-Polyglutamic Acid-Rich Natto in the Early Phase after Eating: A Randomized Crossover Pilot Study

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 915 ◽  
Author(s):  
Risa Araki ◽  
Keiko Fujie ◽  
Nanako Yuine ◽  
Yuta Watabe ◽  
Kazushi Maruo ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Early Phase ◽  
Area Under The Curve ◽  
Postprandial Blood Glucose ◽  
Polyglutamic Acid ◽  
Meal Test ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Test Study ◽  
Significant Difference

The natto containing high levels of gamma-polyglutamic acid (γ-PGA) was recently developed. We investigated the effect of γ-PGA-rich natto consumption on postprandial glycemic excursion in humans. A randomized crossover meal test study was performed on healthy volunteers aged 20–64 years using the following test meals: (1) white rice (WR), (2) low-γ-PGA natto meal (WR + low-γ-PGA natto), and (3) high-γ-PGA natto meal (WR + high-γ-PGA natto). Blood samples were obtained at each visit before and for 120 min after loading. The incremental area under the curve (IAUC) of blood glucose and insulin levels was calculated and compared among the test meals. The blood glucose’s IAUC at 0–120 min, the primary endpoint, was 20.1% and 15.4% lower for the high- and low-γ-PGA natto meal than for the WR, with a significant difference only between the high-γ-PGA natto meal and WR (p < 0.05). The blood glucose’s IAUC at 0–15, 0–30, and 0–45 min was lower for the high-γ-PGA natto meal than for the low-γ-PGA natto meal (all p < 0.05). The possibility that high-γ-PGA natto might suppress blood glucose elevations in the early phase after eating is indicated.

scholarly journals Single-Dose Pinitol Ingestion Suppresses Post-Prandial Glucose Levels: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial

2019 ◽  
Vol 14 (12) ◽  
pp. 1934578X1989081
Author(s):  
Yoshio Suzuki ◽  
Keishoku Sakuraba ◽  
Takuya Wada ◽  
Naoya Watabane ◽  
Seijiro Wada ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Single Dose ◽  
Blood Glucose ◽  
Crossover Trial ◽  
Postprandial Blood Glucose ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Glucose Levels ◽  
Blood Glucose Levels

Limited studies have demonstrated that chronic consumption of pinitol improved glucose tolerance, and single-dose ingestion (0.6 g) 60 minutes prior to meals suppressed postprandial glucose levels in patients with type 2 diabetes mellitus. However, higher doses (6 g) were required in healthy people who ingested pinitol with a meal. This randomized, double-blind, placebo-controlled, crossover trial was conducted to clarify the effect of 0.6 g of pinitol with a meal on postprandial blood glucose levels in healthy adults. Twenty volunteers aged 18 to 25 years participated in this study. Participants visited the laboratory after an overnight fast. After measuring fasting blood glucose levels (FBG), they consumed test food (0.6 g of pinitol or placebo) and then ate breakfast (577 kcal; protein 14.0 g; fat 5.6 g; and carbohydrate 117.7 g). Blood glucose levels were measured immediately after eating and at 30, 60, 90, and 120 minutes after breakfast. Participants’ mean FBG level was 102.6 ± 8.2 mg/dL. Participants were categorized by their FBG as normal ( n = 5; ≤99 mg/dL) or impaired glucose tolerance (IGT) ( n = 15; 100-125 mg/dL). The incremental area under the curve of blood glucose over 120 minutes after the meal was significantly suppressed by pinitol in the IGT group ( P < 0.05), but not in the normal group. Therefore, pinitol was considered to maintain postprandial blood glucose levels in healthy people with IGT, and may contribute to the prevention of type 2 diabetes.

scholarly journals Effect of low-sugar and High-dietary Fiber Noodles on Glycemic Response in Healthy Humans: A Cross-over Trial

2020 ◽  
Author(s):  
Kazunari Kadokura ◽  
Tsuyoshi Tomita ◽  
Sachiyo Hata ◽  
Kazuhiko Kamata ◽  
Kohei Suruga
Keyword(s):  
Blood Glucose ◽  
Dietary Fiber ◽  
Postprandial Blood Glucose ◽  
Glycemic Response ◽  
Insulin Levels ◽  
Glucose Levels ◽  
Healthy Humans ◽  
Blood Glucose Levels ◽  
Restriction Method ◽  
Diet Intake

Abstract Background: Low-carbohydrate diets are popular nutritional therapeutics based on recommendations of the American Diabetes Association (2013). In previous reports, we suggested a new diet-intake restriction method using low-sugar, high-dietary fiber noodles containing okara and konjac and reported their effect on blood glucose levels in healthy animals and animal models of type 2 diabetes. This study aimed to compare the effect of low-sugar, high-dietary fiber noodles with that of normal wheat noodles on glycemic response in healthy adult men.Methods: The study was a randomized, cross-over design to investigate the effects of normal wheat noodles versus low-sugar, high-dietary fiber noodles on glucose and insulin responses at 120 min. Plasma glucose and insulin levels were measured at 0, 15, 30, 45, 60, and 120 min after intake of normal wheat noodles or low-sugar, high-dietary fiber noodles.Results: No abnormalities and side effects were observed in the low-sugar, high-dietary fiber noodles group. Additionally, in men who consumed low-sugar, high-dietary fiber noodles, the increase in postprandial blood glucose levels and insulin levels was significantly suppressed compared with that in men who consumed normal wheat noodles. Conclusions: To the best of our knowledge, this is the first report on the effectiveness of low-sugar, high-dietary fiber noodles on postprandial blood glucose levels in healthy humans; our findings also suggest that such type of noodles might be beneficial for patients with diabetes or celiac disease who consume noodles.Trial registration: UMIN000023986

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

2019 ◽  
Vol 9 (8) ◽  
pp. 532
Author(s):  
Ryuji Takeda ◽  
Yumiko Furuno ◽  
Shigeru Imai ◽  
Yumiko Ide ◽  
Danyong Wu ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Area Under The Curve ◽  
Postprandial Blood Glucose ◽  
Lower Blood Glucose ◽  
Glucose Levels ◽  
Cooked Rice ◽  
Blood Glucose Levels ◽  
Lower Blood ◽  
Tea Extract

Objective: The current study aimed to examine the effect of a single ingestion of a beveragecontaining Pu-erh tea extract (Pu-erh tea polyphenol 32.48mg, eq. gallic acid) on postprandialblood 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 suppressingthe increase in postprandial blood glucose levels after being loaded with cooked rice.Keywords: Pu-erh tea, postprandial blood glucose, cooked rice, type 2 diabetes

scholarly journals Evaluation of the impact of orally administered carbohydrates on postprandial blood glucose levels in different pre-clinical models

2016 ◽  
Vol 52 (4) ◽  
pp. 761-769 ◽  
Author(s):  
Any de Castro Ruiz Marques ◽  
Fabiana Percinoto Monteiro Schiavon ◽  
Patricia Batista Travassos ◽  
Vanessa Fontana Eik ◽  
Guilherme Godoy ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Postprandial Blood Glucose ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Clinical Models ◽  
The Impact
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