Table 1 Characteristics of 31 included randomized controlled trials
Reference | Study design | No.of subjects (M/F) | Age (y) | Country or Region | Population | Duration | Tea group | Control group |
|---|---|---|---|---|---|---|---|---|
Basu 2011 [23] | P | 25(5/20) | 43.7 ± 3 | USA | Obese, | 8wk | decaffeinated GTE beverage (928 mg catechins) | Placebo (water) |
Bogdanski 2012 [24] | P | 56(28/28) | 50.4 ± 8 | Poland | Obese | 3mo | GTE capsule(208 mg EGCG) | placebo (cellulose) |
Brown 2009 [25] | P | 88(88/0) | 51.4 ± 6.4 | UK | Overweight/obese | 8wk | decaffeinated GTE capsule (800 mg EGCG) | Placebo (lactose) |
Brown 2011 [26] | C | 66(66/0) | 49.5 ± 5.6 | UK | Overweight/obese | 6wk | decaffeinated GTE capsule (800 mg catechins) | Placebo (lactose) |
Chan 2006 [27] | P | 34(0/34) | 34.8 ± 4.2 | China | obese | 3mo | GTE capsule (661.3 mg cathchins, 152.8 caffeine) | placebo |
Chen 2016 [28] | P | 77(0/77) | 44.5 ± 11.5 | Taiwan | Obese | 12wk | decaffeinated GTE capsule (1344 catechins) | placebo (cellulose) |
Diepvens 2006 [29] | P | 46(0/46) | 41.6 ± 10 | Netherlands | Overweight | 12wk | GTE capsule (1125 mg catechins, 225 mg caffeine) | placebo |
Frank 2009 [30] | P | 33(33/0) | 40.5 ± 10 | UK | Overweight | 3wk | GTE capsule (672 mg catechins, 114 mg caffeine) | Placebo (matched with caffeine) |
Freese 1999 [31] | P | 20(0/20) | 23–50 | Finland | Healthy | 4wk | GTE capsule (630 mg cathchins,150 caffeine) | Placebo (saccharose, microcrystalline, cocoa) |
Fukino 2008 [32] | C | 60(49/11) | 53.6 ± 8.2 | Japan | Diabetes, overweight | 2mo | GTE beverage (456 mg catechins, 102 mg caffeine) | No intervention |
Hsu 2008 [33] | P | 78(0/78) | 43.5 ± 12 | Taiwan | Obese | 3mo | GTE capsule (613.5 mg cathchins, 27.3 caffeine) | Placebo |
Hsu 2011 [34] | P | 68(24/44) | 51.4 ± 9.2 | Taiwan | Obese, Diabetes | 16wk | decaffeinated GTE capsule (1344 catechins) | placebo (cellulose) |
Huang 2018 [35] | C | 73(0/73) | 55 ± 9.5 | Taiwan | Overweight/obese | 6wk | decaffeinated GTE capsule (1344 catechins) | Placebo (microcrystalline cellulose) |
Kafeshani 2017 [36] | P | 32(32/0) | 21 ± 2 | Iran | Healthy | 6wk | GTE capsule (240 mg catechins) | placebo (maltodextrin) |
Lee 2016 [37] | P | 77(66/11) | 62 ± 12 | Taiwan | Chronic Stable Angina, overweight | 6wk | decaffeinated GTE capsule (600 mg polyphenol) | placebo |
Liu 2014 [38] | P | 77(32/45) | 54.3 ± 7 | Taiwan | Diabetes, obese | 16wk | decaffeinated GTE capsule (1344 catechins) | placebo (cellulose) |
Lu 2016 [39] | P | 64(0/64) | 29 ± 10 | Taiwan | Acne | 4wk | decaffeinated GTE capsule (1344 catechins) | placebo (cellulose) |
Maki 2009 [40] | P | 128(67/61) | 48 ± 9 | USA | Obese | 12w | GTE beverage (625 mg catechins, 39 mg caffeine) | Placebo (matched with caffeine) |
Maron 2003 [41] | P | 240(100/140) | 54.7 ± 11 | China | Hypercholesterolemia, overweight | 12wk | GTE capsule (150 mg cathchins) | Placebo (inertingredients) |
Mielgo-Ayuso 2014 [42] | P | 83(0/83) | 18–49 | Spain | Obese | 12wk | 300 mg EGCG | Placebo (lactose) |
Miyazaki 2013 [43] | P | 52(20/32) | 69.1 ± 5.9 | Japan | Not obese | 14wk | GTE beverage (630.9 mg catechins, 77 mg caffeine) | GTE beverage (88.7 mg catechins and 82.4 mg caffeine) |
Nagao 2007 [44] | P | 240(140/100) | 41.7 ± 9.9 | Japan | Overweight | 12wk | GTE beverage (582.8 mg catechins, 72.3 caffeine) | GTE beverage (96 mg catechins, matched with caffeine) |
Nagao 2009 [45] | P | 43(18/25) | 63.9 ± 2 | Japan | Diabetes, overweight | 12wk | GTE beverage (582.8 mg catechins, 72.3 caffeine) | GTE beverage (96 mg catechins, matched with caffeine) |
Nantz 2009 [46] | P | 111 (46/65) | 29 ± 10.9 | USA | Healthy | 3mo | decaffeinated GTE capsule (320 catechins) | Placebo (maltodextrin) |
Princen-a 1998 [47] | P | 30 | 33.5 ± 13 | Netherlands | Healthy | 4wk | GTE beverage (851.7 mg catechins) | Placebo (mineral water) |
Princen-b 1998 [47] | P | 28 | 34 ± 12 | Netherlands | Healthy | 4wk | GTE capsule (2488.7 mg catechins) | Placebo (mineral water) |
Samavat 2016 [48] | P | 936(0/936) | 60 ± 5 | USA | Healthy | 12mo | decaffeinated GTE capsule (1315 mg catechins) | Placebo (maltodextrin and cellulose) |
Sone 2011 [49] | P | 51(18/33) | 45.7 ± 13.6 | Japan | Healthy | 9wk | GTE beverage (400 mg catechins, 105 mg caffeine) | GTE beverage (100 mg catechins; 80 mg caffeine) |
Suliburska 2012 [50] | P | 46(23/23) | 50.4 ± 8.3 | Poland | Obese | 3mo | GTE capsule (208 mg EGCG) | placebo (cellulose) |
Tadayon 2018 [51] | P | 79(0/79) | 53.3 ± 4 | Iran | Overweight/ obese | 4wk | 800 mg GTE capsule (80-94polyphenol) | placebo |
Venkatakrishnan 2018 [52] | P | 40 | NA | Taiwan | Healthy | 12wk | GTE beverage (780.6 mg of catechin,106.7 caffeine) | placebo |
Wu-a 2012 [53] | P | 69(0/69) | 58.7 ± 6.4 | USA | Healthy | 8wk | decaffeinated GTE capsule (536 mg catechins) | placebo |
Wu-b 2012 [53] | P | 66(0/66) | 59.9 ± 7.9 | USA | Healthy | 8wk | decaffeinated GTE capsule (1072 mg catechins) | placebo |