A catechin-rich beverage improves obesity and blood glucose control in patients with type 2 diabetes.

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 A(1c). 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 A(1c) 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 A(1c) levels in type 2 diabetic patients who do not yet require Ins therapy.

Catechin safely improved higher levels of fatness, blood pressure, and cholesterol in children.

OBJECTIVE: The purpose of this study was to evaluate the effects of a catechin-rich beverage on body fat and cardiovascular disease risk factors in obese children and to verify the safety of its use. METHODS AND PROCEDURES: Obese or near-obese Japanese children were recruited for this study. A double-blind, randomized, controlled study was performed with a 4-week lead-in, a 24-week beverage ingestion period and a 12-week follow-up. Subjects ingested green tea containing 576 mg catechins (catechin group) or 75 mg catechins (control group) once per day for 24 weeks. Randomization was stratified by gender, age, and BMI. Subjects were instructed to maintain their usual lifestyles during the study period. RESULTS: Data were analyzed using samples from 40 subjects (catechin group; n = 21, control group; n = 19). There were no significant differences in major outcome variables, such as body fat mass, between the catechin and the control groups. When, however, the analysis was stratified using the median of the week-0 values, the decrease at week 24 in waist circumference, systolic blood pressure, and low-density lipoprotein cholesterol in the catechin group was significantly greater than that in the control group for the above-median category. Ingestion of the catechin-rich beverage was not associated with any adverse effects. DISCUSSION: These findings suggest that ingestion of a catechin-rich beverage ameliorates serious obesity and cardiovascular disease risk factors without raising any safety concerns in Japanese children.

A green tea extract high in catechins reduces body fat and cardiovascular risks in humans.

OBJECTIVE: The body fat reducing effect and reduction of risks for cardiovascular disease by a green tea extract (GTE) high in catechins was investigated in humans with typical lifestyles. RESEARCH METHODS AND PROCEDURES: Japanese women and men with visceral fat-type obesity were recruited for the trial. After a 2-week diet run-in period, a 12-week double-blind parallel multicenter trial was performed, in which the subjects ingested green tea containing 583 mg of catechins (catechin group) or 96 mg of catechins (control group) per day. Randomization was stratified by gender and body mass index at each medical institution. The subjects were instructed to maintain their usual dietary intake and normal physical activity. RESULTS: Data were analyzed using per-protocol samples of 240 subjects (catechin group; n = 123, control group; n = 117). Decreases in body weight, body mass index, body fat ratio, body fat mass, waist circumference, hip circumference, visceral fat area, and subcutaneous fat area were found to be greater in the catechin group than in the control group. A greater decrease in systolic blood pressure (SBP) was found in the catechin group compared with the control group for subjects whose initial SBP was 130 mm Hg or higher. Low-density lipoprotein (LDL) cholesterol was also decreased to a greater extent in the catechin group. No adverse effect was found. DISCUSSION: The continuous ingestion of a GTE high in catechins led to a reduction in body fat, SBP, and LDL cholesterol, suggesting that the ingestion of such an extract contributes to a decrease in obesity and cardiovascular disease risks.

Effects of diacylglycerol oil on adiposity in obese children: initial communication.

Several studies have shown that diacylglycerol (DAG) oil may suppress accumulation of body fat in adults compared to triacylglycerol (TAG) oil. In this study, we investigated the effect of DAG oil as part of dietetic therapy in obese children. The participants were 11 male and female obese children who were under treatment at the outpatient clinic (four boys, seven girls, age: 7-17 years old). Daily-use cooking oil was changed to DAG oil, and the effects on abdominal fat areas, adipocytokines, and serum lipids were investigated. The total and subcutaneous fat areas significantly decreased in the 5th month after ingestion of DAG oil. Leptin was significantly lower than the initial level after ingestion of DAG oil. The ingestion of DAG oil decreased both the abdominal fat area and leptin in obese children, suggesting that DAG oil prevents obesity in children as well as in adults.

Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men.

BACKGROUND: Catechins, the major component of green tea extract, have various physiologic effects. There are few studies, however, on the effects of catechins on body fat reduction in humans. It has been reported that the body mass index (BMI) correlates with the amount of malondialdehyde and thiobarbituric acid-reactive substances in the blood. OBJECTIVE: We investigated the effect of catechins on body fat reduction and the relation between oxidized LDL and body fat variables. DESIGN: After a 2-wk diet run-in period, healthy Japanese men were divided into 2 groups with similar BMI and waist circumference distributions. A 12-wk double-blind study was performed in which the subjects ingested 1 bottle oolong tea/d containing 690 mg catechins (green tea extract group; n = 17) or 1 bottle oolong tea/d containing 22 mg catechins (control group; n = 18). RESULTS: Body weight, BMI, waist circumference, body fat mass, and subcutaneous fat area were significantly lower in the green tea extract group than in the control group. Changes in the concentrations of malondialdehyde-modified LDL were positively associated with changes in body fat mass and total fat area in the green tea extract group. CONCLUSION: Daily consumption of tea containing 690 mg catechins for 12 wk reduced body fat, which suggests that the ingestion of catechins might be useful in the prevention and improvement of lifestyle-related diseases, mainly obesity.

Dietary diacylglycerol suppresses high fat diet-induced hepatic fat accumulation and microsomal triacylglycerol transfer protein activity in rats.

We have recently shown that the long-term ingestion of dietary diacylglycerol (DAG) mainly containing 1,3-isoform reduces body fat accumulation in humans as compared to triacylglycerol (TAG) with the same fatty acid composition. The fat reduction in this human experiment was most pronounced in visceral fat and hepatic fat. Recent animal studies have also indicated that dietary DAG induces alteration of lipid metabolism in the rat liver. In the present study, the dietary effects of DAG on high fat diet-induced hepatic fat accumulation and hepatic microsomal triglyceride transfer protein (MTP) activity were examined in comparison with those of TAG diet in rats. When the TAG oil content was increased from 10 to 30 g/100 g diet, hepatic TAG concentration, hepatic MTP activity and MTP large subunit mRNA levels were significantly increased after 21 days. However, when the dietary TAG oil (30 g/100 g diet) was replaced with the same concentration of DAG oil with the same fatty acid composition, the increase of the TAG concentration and the MTP activity in the liver were significantly less and the mRNA levels remained unchanged. The MTP activity levels correlated significantly with hepatic TAG concentration.These results showed that dietary DAG may suppress high fat diet-induced MTP activity in the liver, and indicated the possibility that hepatic TAG concentration may regulate hepatic MTP activity.