著者

Tadashi HASE Yumiko KOMINE Shinichi MEGURO Yoko TAKEDA Hidekazu TAKAHASHI Yuji MATSUI Setsujiro INAOKA Yoshihisa KATSURAGI Ichiro TOKIMITSU Hiroyuki SHIMASAKI Hiroshige ITAKURA

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.50, no.7, pp.599-605, 2001 (Released:2002-06-28)

参考文献数

41

被引用文献数

60 65

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To examine the anti-obesity effects of tea catechins in humans, a trial study using healthy male subjects (27-47 years). Comprising in equal number a low dose catechin (LDC) group (n=11) and high dose catechin (HDC) group (n=12). The groups were administered catechins at 118.5 mg and 483.0 mg a day for 12 weeks, respectively. At 4 and 12 weeks, effect evaluation was made based on change in weight, body mass index (BMI), waist circumference, body fat ratio and abdominal fat as determined by computed tomography (CT) and triacylglycerol, total cholesterol, free fatty acid, glucose, insulin and total plasminogen activator inhibitor-1 (PAI-1) in serum. In the HDC group, at 12 weeks, weight, BMI, waist circumference, body fat ratio, abdominal fat and total cholesterol, glucose, insulin, PAI-1 in serum were noted to have significantly decreased from values at 0 week. In the LDC group, only weight, BMI and insulin had changed. In the HDC group, BMI had decreased significantly in 25≤BMI subjects compared to 25>BMI subjects. In the 25≤BMI subjects, BMI decreased significantly more in the HDC group. Tea catechins are thus shown here for the first time to have the anti-obesity effects in humans.

著者

Jun-ichi Oyama Toyoki Maeda Makoto Sasaki Kazuya Kozuma Ryuji Ochiai Ichiro Tokimitsu Sachiyo Taguchi Yoshihiro Higuchi Naoki Makino

出版者

The Japanese Society of Internal Medicine

雑誌

Internal Medicine (ISSN:09182918)

巻号頁・発行日

vol.49, no.23, pp.2553-2559, 2010 (Released:2010-12-01)

参考文献数

37

被引用文献数

13 32

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Objective Several epidemiological investigations have reported that green tea reduces cardiovascular and cerebral vascular risks. Green tea catechins may improve peripheral endothelial dysfunction in smokers. The purpose of this study was to elucidate the beneficial effect of green tea catechins on the repair of endothelial dysfunction in smokers. Methods Thirty healthy male smokers divided into three groups ingested a green tea beverage containing 0 mg (control group), 80 mg (middle dose group) or 580 mg (high dose group) of green tea catechins (GTC) daily for two weeks, and endothelial-dependent vasodilatation was investigated by measuring forearm blood flow (FBF) response to reactive hyperemia (RH) by venous occlusion strain-gauge plethysmography. Results An acute effect was that the FBF response to RH significantly increased 2 hr after GTC intake in the high dose group. However, no increase was observed in the other groups. The chronic administration of GTC for one or two weeks ameliorated the FBF responses to RH in the high dose group. On the other hand, no significant increase was observed in the FBF responses to RH in the other groups. Moreover, the plasma concentration of 8-OHdG, IL-6, TNF-alpha, and soluble Fas decreased significantly for two weeks in the high dose group, however, the level of IL-1 beta remained unchanged over this period. Conclusion Green tea consumption over short and long periods appears to ameliorate endothelial dysfunction by scavenging free radicals with anti-inflammatory and anti-apoptotic properties in healthy male smokers.

著者

Shinichi MEGURO Tomohito MIZUNO Kouji ONIZAWA Keiko KAWASAKI Hideaki NAKAGIRI Yumiko KOMINE Junko SUZUKI Yuji MATSUI Tadashi HASE Ichiro TOKIMITSU Hiroyuki SHIMASAKI Hiroshige ITAKURA

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.50, no.7, pp.593-598, 2001 (Released:2002-06-28)

参考文献数

29

被引用文献数

14 16 17

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Examination was made of the effects of tea catechins (TC) on diet-induced obesity. Exposure to high-fat-diet (30% fat) in C57BL/6J mice for 4 weeks induced significant increase in body weight, visceral fat (epididymal, mesenteric, retroperitoneal, perinephric) weight and plasma concentrations of glucose, triacylglycerol and leptin, compared to low-fat diet (5% fat). Treatment with 0.1%TC (high-fat diet +0.1%TC group) had little effect on diet-induced obesity. Relative to high-fat diet and 0.1%TC treatment, 0.5%TC treatment (high-fat diet +0.5%TC group) was noted to bring about significant decrease in body weight, visceral, fat weights and plasma leptin. Lipid absorption rate was the same with the high fat diet and 0.5%TC treatment. An oral soluble starch and sucrose (SS-S) tolerance test was conducted on C57BL/6J mice to evaluate the effects of TC to sugar absorption. When the ratio of TC to sum of SS-S was the same as that in the diet composition for the 0.5%TC treatment, the plasma glucose level showed no response. These results demonstrate for the first time TC to have antiobesity effects on diet-induced obesity in mice, and suggest these effects to be exerted through a mechanism that would not involve inhibition of intestinal absorption of sugar and lipid.

著者

Tomonori NAGAO Shinichi MEGURO Satoko SOGA Atsuko OTSUKA Kazuichi TOMONOBU Shinichi FUMOTO Akiro CHIKAMA Kenta MORI Masayuki YUZAWA Hiroyuki WATANABE Tadashi HASE Yukitaka TANAKA Ichiro TOKIMITSU Hiroyuki SHIMASAKI Hiroshige ITAKURA

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.50, no.9, pp.717-728, 2001 (Released:2002-06-28)

参考文献数

34

被引用文献数

33 36

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The body fat reducing effect of tea catechins was previously confirmed in humans. The effects of tea catechins for reducing body fat were thus studied as basis for actual application. Three experiments on healthy male adults (n=82) were conducted to determine the effects of long-term tea catechins administration on body fat and biochemical blood parameters. First experiment: tea catechins were given as oolong tea-like beverage for 12 weeks. In 600 and 900 mg groups, visceral fat was significantly loss than in the control (600 mg group p=0.0317, 900 mg group p=0.0098). The effects were more pronounced at greater of tea catechins administration. No significant changes in biochemical blood parameters including fat-soluble vitamins were detected. Second experiment : oolong tea-like beverage containing tea catechins at nearly same amounts on in the 600 mg group was given for 20 weeks. Abdominal fat, including visceral fat, was significantly loss than in the control (total fat area p<0.0001, visceral fat area p=0.0004, subcutaneous fat area p=0.0001). Plasma PAI-1 was also significantly decreased (p=0.0080). Third experiment : green tea-like (GT group) and oolong tea-like (OT group) beverages containing approximately 540 mg tea catechins were given for 12 weeks. In the two groups, visceral fat was significantly loss than in the control (GT group p=0.0284, OT group p=0.0095) and the effects of two beverages were similar. Long-term tea catechins administration at 500 to 600 mg/day in humans would thus appear to reduce body fat without influencing fat-soluble vitamins, of which the absorption may be inhibited, and various serum and plasma indices regardless of the kind of beverages.