2.1. Udział w utrzymaniu lub osiągnięciu prawidłowej masy ciała (ID 1107, 1112, 1544, 2716)

The claimed effects are “weight management/metabolism of lipids”, “weight management” and “control of weight”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effects refer to an increased oxidation of body fat leading to the loss of fat mass and body weight.
Weight management can be interpreted as contribution to the maintenance of a normal body weight. In this context a moderate weight loss in overweight subjects without achieving a normal body weight is considered to be a beneficial physiological effect.
The Panel considers that the contribution to the maintenance or achievement of a normal body weight is a beneficial physiological effect.

2.2. Zwiększenia beta-oksydacji kwasów tłuszczowych prowadzące do redukcji tkanki tłuszczowej (ID 1123, 1124, 3698)

The claimed effects are “resting metabolic rate and thermogenesis”, “fat metabolism” and “supports metabolism/fat oxidation”. The Panel assumes the target population is overweight individuals in the general population who wish to reduce their fat mass.
In the context of the proposed wordings, the Panel assumes that the claimed effects refer to an increased beta-oxidation of fat and fatty acids, which is a measurable outcome. An increase in fat oxidation may lead to a decrease in body fat, which might be considered a beneficial physiological effect.
The Panel considers that an increased beta-oxidation of fatty acids leading to a reduction in body fat mass is a beneficial physiological effect.

2.3. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 1115, 1545)

The claimed effects are “glucose metabolism” and “blood glucose levels”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the maintenance of normal blood glucose concentrations.
The Panel considers that long-term maintenance of normal blood glucose concentrations is a beneficial physiological effect.

3.1. Udział w utrzymaniu lub osiągnięciu prawidłowej masy ciała (ID 1107, 1112, 1544)

A total of 48 references were cited in relation to the claimed effect. Twelve references were reviews on the mechanisms by which green tea catechins (GTCs) could exert the claimed effect, but provided no original data. Three references provided information on technological and quality aspects of green tea. Other references reported on the acute effects of green tea supplements on energy expenditure
and nutrient utilisation but did not report on body weight. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Nine references provided data from human intervention studies on the effects of green tea catechins on weight management (Chan et al., 2006; Diepvens et al., 2006; Hase et al., 2001; Kovacs et al., 2004; Nagao et al., 2005, 2007; Takashi et al., 2002; Tsuchida et al., 2002; Westerterp-Plangtenga et al., 2005). The papers by Takashi et al. (2002) and Tsuchida et al. (2002) were published in the same Journal and the abstract contained the same information, so apparently referred to the same study.
All of these references with the exception of Takashi et al. (2002) have been considered in a recently published meta-analysis of randomised, double-blind, controlled trials (RCT) which investigated the effects of GTCs with or without caffeine on body weight (Phung et al., 2010).
A total of 15 trials (n=1,243) met the inclusion criteria for the meta-analysis by Phung et al. (2010). Of the 15 trials included, seven trials (n=600) evaluated GTCs with caffeine compared with a caffeine-matched control, six trials (n=524) evaluated GTCs with caffeine compared with a caffeine-free control, and two trials (n=119) evaluated caffeine-free GTCs compared with a caffeine-free control. The Panel notes that studies testing the effects of GTCs plus caffeine compared to a caffeine-free control do not allow conclusions to be drawn on the effects of GTCs alone because an interaction between GTCs and caffeine on the claimed effect cannot be excluded from the data provided. The Panel considers that no conclusions can be drawn from these studies or the meta- analysis by Phung et al. (2010) for the scientific substantiation of the claimed effect.
In a randomised, double-blind, placebo-controlled and parallel study, Takeshita et al. (2008) investigated the effects of GTCs on body weight in 81 healthy Japanese overweight and obese men (BMI≥25) who were randomly assigned to consume one bottle of sports drink per day containing decaffeinated green tea extract (548 mg GTC and 0 mg caffeine: catechin group, n=40), or one bottle of sports drink per day (0 mg of both GTCs and caffeine: placebo group, n=41) over 12 weeks. At the end of the study, body weight was significantly lower in the catechin group than in the placebo group. As only the abstract and tables in this publication were in English, and the full text was available in Japanese only, the Panel could not perform a complete evaluation of this study.
In a second randomised, double-blind, placebo-controlled and parallel study, Hill et al. (2007) randomised 42 overweight or obese post-menopausal women to consume either EGCG (300 mg/d) or placebo (lactose) twice daily for 12 weeks. Subjects were excluded if regular tea consumption exceeded three cups per day and/or habitual caffeine intake exceeded 300 mg per day. A total of 38 subjects completed the study (19 per group). Both groups were prescribed moderate physical exercise during the study (i.e. an exercise programme requiring running or walking for 45 minutes, three times per week at a heart rate which corresponded to 75 % of their age predicted maximum). No significant differences between groups were observed with respect to body weight changes
(0.08 kg 0.21 vs. -0.45 kg 0.27, in the intervention versus the placebo groups, respectively).
In weighing the evidence, the Panel took into account that the only intervention study from which sufficient information was available for a scientific evaluation found no effect of EGCG consumption on body weight.
The Panel concludes that a cause and effect relationship has not been established between the consumption of catechins (including EGCG) from green tea (Camellia sinensis (L.) Kuntze) and contribution to the maintenance or achievement of a normal body weight.

3.2. Zwiększenia beta-oksydacji kwasów tłuszczowych prowadzące do redukcji tkanki tłuszczowej (ID 1123, 1124, 3698)

The references provided for the substantiation of this claim included narrative reviews on food constituents other than tea or tea catechins; narrative reviews on the health effects of oolong tea, green tea, and/or EGCG; human intervention studies which assessed the interaction between GTCs and caffeine on different outcomes including fat oxidation, but which did not provide original data; studies on the effects of oolong tea on energy expenditure and fat oxidation but which did not report on the catechin content of the study materials; and studies and reviews on the mechanisms by which tea/EGCG could mediate different effects, including an increase in fat oxidation.
Only one one-arm, open label intervention study in humans was provided which assessed the effects of a green tea extract containing 25 % EGCG on body weight and waist circumference in moderately obese subjects for three months (Chantre and Lairon, 2002). Changes in body fat were not reported. The Panel considers that no conclusions can be drawn from this uncontrolled study for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of catechins (including EGCG) from green tea (Camellia sinensis (L.) Kuntze) and an increased beta-oxidation of fatty acids leading to a reduction in body fat mass.

3.3. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 1115, 1545)

A total of 46 publications were cited in relation to the claimed effect. Some of the references referred to animal and in vitro studies, or provided details about the metabolism and pharmacokinetics of catechins, whilst others reported on the association between dietary catechins and disease risk or disease prevention (e.g. type II diabetes, cardiovascular disease, liver disease, atherosclerosis and cancer) in observational (cohort) studies. Other references were reviews dealing with dietary sources of polyphenols and health-promoting properties of green tea unrelated to glucose metabolism. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Only five of the human studies provided examined the effect of catechins from green tea on blood glucose. However, three of the studies (Fukino et al., 2005, 2008; Hosoda et al., 2003) included insulin-dependent or non-insulin dependent diabetic subjects on either insulin or oral anti-diabetic therapy. The Panel considers that the evidence provided in these studies does not predict the occurrence of an effect of GTCs on the long-term maintenance of normal blood glucose concentrations in the general population. Also, one of the studies investigated the effect of GTCs on post-prandial glycaemic and insulinaemic responses (Tsuneki et al., 2004). The Panel considers that no conclusions can be drawn from these measures in relation to the long-term maintenance of normal blood glucose concentrations.
In the study by Ryu et al. (2006), 55 type II diabetic patients (24 women) who were not regular tea consumers drank 900 mL of water containing 9 g of green tea daily and 900 mL of water alone for four weeks each following a randomised, cross-over design. The Panel notes that whilst it is not stated whether subjects were taking blood glucose lowering medications or not, an exclusion criterion was uncontrolled diabetes. The Panel also notes that green tea was not sufficiently characterised regarding its catechin content, and that fasting blood glucose concentrations are not a reliable marker of long- term blood glucose control. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claimed effect.
The Panel concludes that a cause and effect relationship has not been established between the consumption of catechins (including EGCG) from green tea (Camellia sinensis (L.) Kuntze) and the long-term maintenance of normal blood glucose concentrations.