Dostal Allison M, Arikawa Andrea, Espejo Luis, Kurzer Mindy S
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN; and.
Department of Nutrition and Dietetics, University of North Florida, Jacksonville, FL.
J Nutr. 2016 Feb;146(2):256-64. doi: 10.3945/jn.115.219238. Epub 2015 Dec 23.
Green tea extract (GTE) consumption has been linked to favorable changes in adiposity and bone mineral density (BMD), although it is unknown if these effects are due to green tea catechins or caffeine. The catechol-O-methyltransferase (COMT) genotype may also modify these associations.
We examined the impact of decaffeinated GTE on body composition (using dual-energy X-ray absorptiometry) and obesity-associated hormones.
The Minnesota Green Tea Trial was a 12-mo randomized, double-blind, placebo-controlled clinical trial in 937 postmenopausal women (aged 50-70 y) assigned to receive either GTE containing 843 mg (-)-epigallocatechin-3-gallate or placebo. This substudy was conducted in 121 overweight/obese participants [body mass index (BMI) (kg/m(2)) ≥25.0].
There were no differences in changes in BMI (-0.13 ± 0.11 compared with -0.05 ± 0.11; P = 0.61), total fat mass (-0.30 ± 0.16 compared with -0.12 ± 0.15 kg; P = 0.40), percentage of body fat (-0.15% ± 0.17% compared with -0.15% ± 0.16%; P = 0.99), or BMD (-0.006 ± 0.002 compared with -0.003 ± 0.002 g/cm(2); P = 0.49) over 12 mo between women taking GTE (n = 61) and those taking a placebo (n = 60). Interactions were observed between treatment and time for gynoid percentage of fat (%fat) and tissue %fat. Gynoid %fat increased from baseline to month 12 in the placebo group as baseline BMI increased and decreased over time as baseline BMI increased in the GTE group (P-interaction = 0.02). Tissue %fat increased from baseline to month 12 in the placebo group as baseline BMI increased. In the GTE group, tissue %fat decreased during the intervention as baseline BMI increased (P-interaction = 0.04). No changes were seen in circulating leptin, ghrelin, adiponectin, or insulin concentrations. COMT genotype did not modify the effect of GTE on any variable.
Decaffeinated GTE was not associated with overall reductions in adiposity or improvements in BMD in overweight/obese postmenopausal women. However, GTE may be beneficial for reduction in tissue and gynoid %fat in individuals with higher BMI. This clinical trial was registered at www.clinicaltrials.gov as NCT00917735.
饮用绿茶提取物（GTE）与肥胖及骨矿物质密度（BMD）的有益变化有关，不过尚不清楚这些影响是源于绿茶儿茶素还是咖啡因。儿茶酚-O-甲基转移酶（COMT）基因型也可能会改变这些关联。
我们研究了脱咖啡因GTE对身体成分（使用双能X线吸收法）及肥胖相关激素的影响。
明尼苏达绿茶试验是一项为期12个月的随机、双盲、安慰剂对照临床试验，937名绝经后女性（年龄50 - 70岁）被分配接受含有843毫克（-）-表没食子儿茶素-3-没食子酸酯的GTE或安慰剂。本亚组研究在121名超重/肥胖参与者[体重指数（BMI）（kg/m²）≥25.0]中进行。
服用GTE的女性（n = 61）和服用安慰剂的女性（n = 60）在12个月期间，BMI变化（-0.13 ± 0.11与-0.05 ± 0.11相比；P = 0.61）、总脂肪量（-0.30 ± 0.16与-0.12 ± 0.15千克相比；P = 0.40）、体脂百分比（-0.15% ± 0.17%与-0.15% ± 0.16%相比；P = 0.99）或骨密度（-0.006 ± 0.002与-0.003 ± 0.002克/厘米²相比；P = 0.49）均无差异。观察到治疗与时间之间对于臀部脂肪百分比（%脂肪）和组织%脂肪存在相互作用。安慰剂组中，臀部%脂肪从基线到第12个月随着基线BMI升高而增加，而在GTE组中，随着基线BMI升高，臀部%脂肪随时间下降（P相互作用 = 0.02）。安慰剂组中，组织%脂肪随着基线BMI升高从基线到第12个月增加。在GTE组中，干预期间组织%脂肪随着基线BMI升高而下降（P相互作用 = 0.04）。循环中的瘦素、胃饥饿素、脂联素或胰岛素浓度未见变化。COMT基因型未改变GTE对任何变量的影响。
脱咖啡因GTE与超重/肥胖绝经后女性的总体肥胖减轻或骨密度改善无关。然而，GTE可能有益于降低BMI较高个体的组织及臀部%脂肪。该临床试验已在www.clinicaltrials.gov注册，注册号为NCT00917735。
