Effect of green tea extract on obese women: A randomized, double-blind, placebo-controlled clinical trial

ArticleinClinical nutrition (Edinburgh, Scotland) 27(3):363-70 · June 2008with122 Reads
DOI: 10.1016/j.clnu.2008.03.007 · Source: PubMed
To examine the effect of green tea extract (GTE) on obese women and to explore the relationship between GTE and obesity-related hormone peptides. A randomized, double-blind, placebo-controlled clinical trial was conducted from July 2006 to June 2007 in Taipei Hospital, Taiwan. Seventy-eight of 100 obese women aged between 16 and 60 years with BMI>27 kg/m(2) and who had not received any other weight control maneuvers within the last 3 months completed this study. The subjects were randomly divided into Groups A and B. Group A (n=41) received GTE while Group B (n=37) took cellulose as a placebo, one capsule (400mg) three times each day for 12 weeks. The body weight (BW), body mass index (BMI) and waist circumflex (WC) were measured at the beginning of the study and after 12 weeks of treatment with GTE. The data were compared and expressed as % reduction. There was only a 0.3% reduction in BW (0.15 kg) after 12 weeks of treatment with GTE. There was no statistical difference in % reduction in BW, BMI and WC between the GTE and placebo groups. Within group comparison revealed that the GTE group had significant reduction in LDL-cholesterol and triglyceride, and marked increase in the level of HDL-cholesterol, adiponectin and ghrelin. On the other hand, the placebo group showed significant reduction in triglyceride only, and a marked increase in the level of ghrelin alone. This study showed no statistical difference in % reduction in BW, BMI and WC between the GTE and placebo groups after 12 weeks of treatment. The intake of GTE (491 mg catechins containing 302 mg EGCG) for 12 weeks is considered safe as shown by the results.
    • "The mechanism underlying this response is undetermined. With regard to blood lipids Hsu et al. [10] reported a significant reduction in TG and LDL and a significant increase in HDL following 12 weeks of green tea consumption in overweight women. Participants in the present study possessed lower resting levels of TG, LDL, and glucose and higher levels of HDL. "
    [Show abstract] [Hide abstract] ABSTRACT: The combined effect of green tea ingestion and interval sprinting exercise on body and abdominal fat of overweight males was investigated. Participants were randomly assigned into control (C), green tea (GT), interval sprinting exercise (ISE), and green tea and ISE (GT + ISE) groups. The GT, GT + ISE, and C groups consumed three GT capsules daily. The ISE and GT + ISE groups completed 36 ISE sessions over 12 weeks. Forty eight overweight males with a mean BMI of 28.5 ± 0.92 kg/m² and age of 26 ± 0.7 years acted as participants. There was a significant reduction in total and abdominal fat mass for the ISE and GT + ISE groups, p < 0.05, however, total and abdominal fat mass did not significantly change in the GT and C groups. There was a significant increase in total lean mass, p < 0.05, after the intervention for the ISE and GT + ISE groups only. There was a significant increase in fat oxidation during submaximal aerobic exercise, p < 0.05, after the intervention for the ISE, GT + ISE, and GT groups with no change for the C group. Following the 12-week intervention the ISE and GT + ISE groups, compared to C, recorded a significantly greater decrease in body and abdominal fat, and a significant increase in total lean mass. Ingestion of green tea by itself, however, did not result in a significant decrease in body or abdominal fat, but increased fat utilization during submaximal exercise. The combination of 12 weeks of GT ingestion and ISE did not result in greater total and abdominal fat reduction compared to 12 weeks of ISE alone.
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    • "Unfortunately, a clear comparison was not presented between the two arms of the study, thus, it remains unclear whether the GTE was better/worse or similar to the placebo in terms of weight loss and metabolic parameters in addition to the typical low-energy diet plus placebo. A study by Hsu et al. (2008) [13] investigated the effects of a 12-week GTE dietary supplementation in 78 obese, but otherwise healthy, females who visited an outpatient clinic in Taipei. There were no significant changes revealed in outcome measures (anthropometric characteristics, fasting biomarkers related to CVD, and hormones related to glucose metabolism) between the intervention and the placebo group after 12 weeks. "
    [Show abstract] [Hide abstract] ABSTRACT: Green tea catechins (GTCs) are secondary plant metabolites that have been associated with health benefits in human trials. As such, they have the potential to reduce cardiovascular disease (CVD) risk; however, results are not consistent. This systematic review of the published data assessed the putative effect of GTCs supplementation on anthropometric, blood pressure, and biochemical measures associated with CVD risk. It was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines exploring four major electronic databases (MEDLINE, Cochrane Library, Web of Science, and Scopus). Studies were included if they were published in peer-reviewed journals in English from 1990 until October 2015, and were human double-blind randomized and placebo-controlled trials (RCTs). From 122,428 articles initially identified, after two levels of screening, seven studies met the inclusion criteria. The review revealed consistent and significant (p ď 0.05) reductions in body mass index (BMI), blood pressure and plasma lipids; however, this effect would have been less if between-group effects had been considered. The current evidence base also has considerable methodological limitations due to suboptimal statistical methods used in data analyses. Future research efforts must aim to rectify this paucity of evidence with well-designed and well-reported prospective studies.
    Full-text · Article · Jun 2016
    • "Similarly, Hill et al. observed that there was no significant difference in body weight, BMI, waist circumference, abdominal fat and intra-abdominal adipose tissue between the placebo group and the EGCGsupplemented group in overweight/obese postmenopausal women [42] . In addition, a randomized, double-blinded, placebo-controlled trial in Taiwan reported that there was no statistical difference in % reduction in body weight, BMI and waist circumference in the green tea catechinssupplemented (491 mg catechins) group after 12 weeks of treatment compared to the placebo group [43] . The association between 3 flavonoid subgroups and BMI over a 14-year period in 4280 men and women aged 55-69 years in a prospective cohort study was assessed in the Netherlands. "
    [Show abstract] [Hide abstract] ABSTRACT: Obesity is a major public health concern all over the world. It is considered as a risk factor for the development of diseases like type 2 diabetes and cardiovascular diseases. Because of the high cost of medications used in obesity treatment and possible side effects, the use of alternative forms from natural products is considered as a promising tool in management and treatment of obesity. Flavonoids are group of phenolic compounds that have been extensively studied for their biological activity against many diseases. Evidences from literature suggest the potential role of flavonoids in the fight against obesity. In this Chapter, evidences reported from in vitro, animal and human studies have been discussed. In addition, possible mechanisms of action responsible for their anti-obesity effect is discussed in detail.
    Full-text · Chapter · Feb 2016 · Nutrients
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