A Catechin‐rich Beverage Improves Obesity and Blood Glucose Control in Patients With Type 2 Diabetes

Abstract

We investigated the effects of continuous ingestion of a catechin‐rich beverage in patients with type 2 diabetes who were not receiving insulin (Ins) therapy in a double‐blind controlled study. The participants ingested green tea containing either 582.8 mg of catechins (catechin group; n = 23) or 96.3 mg of catechins (control group; n = 20) per day for 12 weeks. At week 12, the decrease in waist circumference was significantly greater in the catechin group than in the control group. Adiponectin, which is negatively correlated with visceral adiposity, increased significantly only in the catechin group. Although the increase in Ins at week 12 was significantly greater in the catechin group than in the control group, no apparent difference was noted between the two groups in glucose and hemoglobin A1c. In patients treated with insulinotropic agents, the increase in Ins at week 12 was significantly greater in the catechin group than in the control group. This significant increase in Ins levels was observed only in the catechin group. In the catechin group receiving other treatments, Ins levels remained unchanged. In addition, in patients treated with insulinotropic agents, the decrease in hemoglobin A1c at week 12 was significantly greater in the catechin group than in the control group. These results suggest that a catechin‐rich beverage might have several therapeutic uses: in the prevention of obesity; in the recovery of Ins‐secretory ability; and, as a way to maintain low hemoglobin A1c levels in type 2 diabetic patients who do not yet require Ins therapy.

The Effect of Dietary Supplementation of Green Tea Catechins on Cardiovascular Disease Risk Markers in Humans: A Systematic Review of Clinical Trials

“…It was beyond the scope of this review to include and examine sources from 'grey' literature. Despite the variability of effect, with some studies finding conflicting outcomes [28][29][30], the majority of the current literature appears to support the positive therapeutic effect derived from GT consumption [1,[9][10][11][12][13][14][15][31][32][33][34]. Furthermore, as tea consumption is high globally, it could be proposed that even modest health effects in humans may have major beneficial implications for global population health and reduction in CVD risk [21,35].…”

“…Of which, 30 were excluded on the basis of: study design (n = 16), missing outcome data (n = 14), and absence of placebo group (n = 1). The seven remaining studies [9][10][11][12][13][14][15] met the inclusion criteria (Table 1), with a cumulative total of 466 participants aged from 16 to 65, with an average age of 47.7˘9.2 years (mean˘SD). Five of the chosen studies [9][10][11][12][13][14][15] included participants of both gender, whilst the remaining three [10,11,13] examined the effects of GT extract supplementation in females only.…”

“…The seven remaining studies [9][10][11][12][13][14][15] met the inclusion criteria (Table 1), with a cumulative total of 466 participants aged from 16 to 65, with an average age of 47.7˘9.2 years (mean˘SD). Five of the chosen studies [9][10][11][12][13][14][15] included participants of both gender, whilst the remaining three [10,11,13] examined the effects of GT extract supplementation in females only. Furthermore, five of the chosen studies [9][10][11][12][13] investigated the effect of interventions on obese participants, two examined people with type 2 diabetes [14,15], and one studied healthy individuals ( Table 1).…”

Green Tea Modulation of Obesity and Breast Cancer Risk

“…2 Green tea consumption has been shown to be related with decreased body weight and it is thought that it may also reduce inflammation. [3][4][5][6] The goal of this training grant is to study changes in the obesity and energy-related hormones as well as inflammatory markers in healthy postmenopausal women at high risk of breast cancer due to dense breast tissue who consume green tea supplements containing 800 mg epigallocatechin-3-gallate (EGCG) daily for 12 months. Major milestones of this study include recruiting and randomizing all of the training grant study participants, and completing the study for 90% of the target sample size.…”

“…Among proposed mechanisms, reduction in body weight and/or body fat mass as well as inflammation has drawn a great deal of attention within the cancer research community. [3][4][5][6] This training grant aims at evaluating the effects of green tea extract intake on the circulating levels of the energy and obesity-related hormones and inflammatory biomarkers in healthy postmenopausal women, and whether any observed changes vary by the catechol-O-methyltransferase (COMT) genotype. Abovementioned measurements will be performed from the baseline and 12-month visits of a randomized, double-blind, placebo-controlled prevention trial in a population of overweight and obese participants at high risk of breast cancer due to dense breast tissue.…”