ID 1546 -
Galusan epigallokatechiny z herbaty
PL: Galusan epigallokatechiny z herbaty
EN: Epigallo-catechin-3-gallate (EGCG) / Green tea extract, rich in EGCG
Pdf: Camellia sinensis
1. Charakterystyka żywności / składnika
The food constituent that is the subject of the health claims is Camellia sinensis (L.) Kuntze, catechins present in green tea, and epigallo-catechin-3-gallate.
In the wording of claim ID 1105, tannins and fluoride are named as active ingredients in tea in relation to a claimed effect on oral health. The Panel refers to its previous opinion on fluoride in the context of the evaluation of Article 13 claims (EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), 2009); the effects of fluoride (irrespective of the source) on tooth mineralisation will not be considered further in this Opinion.
The plant Camellia sinensis (L.) Kuntze is an evergreen shrub of the Theaceae family. Tea is an extract of the dried leaves from Camellia sinensis (L.) Kuntze and it is usually prepared by infusing the leaves in hot water. The composition of the tea leaves depends on a variety of factors, including climate, season, horticultural practices, and the type and age of the plant. Many kinds of tea are produced, which can be classified into three major types according to the different levels of fermentation: green (un-fermented), oolong (semi-fermented) and black (fully fermented) (Wang et al., 2000).
The composition of tea beverages greatly depends on the type of leaves used, on the degree of fermentation and on the methods of preparation (Kaszkin et al., 2004; Astill et al., 2001). The level of fermentation, the production process, and the method for preparing the tea infusion have not been described in relation to the claims.
Green tea contains polyphenolic compounds, which include flavanols, flavandiols, flavonoids, and phenolic acids. Most of the polyphenols in green tea are catechins. Epigallo-catechin-3-gallate (EGCG) is the most abundant catechin in green tea. In black teas, the most abundant polyphenols are tannins, mainly theaflavin and thearubigin (Mukhtar and Ahmad, 2000). Tea extracts/infusions also contain variable amounts of potentially active food constituents, such as caffeine, theanine or theogallin.
Green tea catechins (including EGCG) and tannins in black tea (mainly theaflavin and thearubigin) can be measured in foods by established methods.
The Panel considers that whereas Camellia sinensis (L.) Kuntze (tea) is not sufficiently characterised in relation to the claimed effects, catechins in green tea (including EGCG) and tannins in black tea (for ID 1105) are sufficiently characterised.
2.6. Utrzymanie prawidłowego ciśnienia tętniczego (ID 1546)
The claimed effect is “cardiovascular health”. The Panel assumes that the target population is the general population.
In the context of the proposed wording, the Panel notes that the claimed effect relates to the maintenance of normal blood pressure.
Blood pressure (BP) is the pressure (per unit area) exerted by circulating blood on the walls of blood
vessels. Elevated BP, by convention 140 mmHg (systolic) and/or 90 mmHg (diastolic), may compromise the normal function of the arteries.
The Panel considers that maintenance of normal blood pressure is a beneficial physiological effect.
3.6. Utrzymanie prawidłowego ciśnienia tętniczego (ID 1546)
Among the references cited in relation to this claim, two referred to laboratory methods for the assessment of components in tea; three presented data from in vitro experiments, e.g. on the effects of tea on vascular smooth muscle cells; one referred to an animal study reporting on outcomes other than BP; eight reported on human epidemiological studies on the relationship between tea consumption and outcome variables other than blood pressure (e.g., markers of atherosclerosis, coronary artery disease (CAD), myocardial infarction, stroke, obesity, blood lipids, cancer); four reported on non- controlled human intervention studies and one on a randomised controlled trial investigating the effects on tea intake in relation to outcome variables other than BP (e.g. oxidative stress, blood lipids); and seven were (non-systematic) review papers that did not include original data on tea drinking and BP. The Panel considers that no scientific conclusions can be drawn from these references for the substantiation of the claim.
Four human intervention studies (Kim et al., 2006; Duffy et al., 2001; Vlachopoulos et al., 2006; Nagaya et al., 2004) and three human observational studies (Hodgson et al., 2003; Stensvold et al., 1992; Yang et al., 2004) investigating the effects of tea on measurements of BP were cited for the substantiation of the claimed effect.
The Panel notes that one of the intervention studies (Duffy et al., 2001), cited in one of the narrative reviews provided (Vita, 2003), did not address the effects of green tea (including EGCG) but rather of black tea, that a second study lacked a randomised-controlled design (Kim et al., 2006) and that the remaining two intervention studies assessed only the acute effects of green tea consumption on BP, that is green tea was administered on a single occasion (Vlachopoulos et al., 2006; Nagaya et al., 2004). In addition, none of the human intervention studies cited above report on daily intakes of the food constituent that is the subject of this health claim (i.e., EGCG in green tea). The Panel considers that no conclusions can be drawn from these studies for the substantiation of the claimed effect.
Hodgson et al. (2003) performed a cross-sectional epidemiological study in which tea intake and a biomarker of exposure (4-O-methylgallic acid in 24-h urine) were examined in relation to BP. The study included 218 women >70 years old with a mean BP of 138/74 mmHg and a mean daily tea intake of 525 mL. Tea intake comprised both black tea and green tea. A cohort study by Stensvold et al. (1992) examined the relationship between tea consumption and systolic BP. The study included ~20,000 Norwegian women aged 35-49 years with no history of cardiovascular disease or diabetes. The Panel notes that this study also focused on black tea consumption. The Panel considers that no conclusions can be drawn from these studies for the substantiation of the claim.
In a prospective epidemiological study by Yang et al. (2004), tea drinking in relation to the risk of hypertension was studied in 1,507 Taiwanese men and women aged >20 years with no history of hypertension. Detailed data on tea intake were obtained. Six hundred subjects (39.8%) were habitual tea drinkers, defined by tea consumption of 120 mL per day or more for more than one year. Of these, 96.3% were green or oolong tea drinkers and 4.8% added milk to their tea. The Panel notes that this study did not report on daily intakes of the food constituent that is the subject of the health claim (i.e., EGCG in green tea), and therefore considers that no conclusions can be drawn from this study for the substantiation of the claim.
Three animal studies on the relationship between tea consumption and blood pressure were cited (Negishi et al., 2004; Potenza et al., 2007; Ikeda et al., 2007). The Panel considers that the evidence provided in these animal studies is not sufficient to predict the occurrence of an effect of green tea (including EGCG) consumption on the maintenance of normal blood pressure in humans.
In weighing the evidence, the Panel took into account that none of the human studies presented reported on daily intakes of the food constituent that is the subject of the health claim (i.e., EGCG in green tea), and that the evidence provided in the animal studies is not sufficient to predict the occurrence of an effect of green tea (including EGCG) consumption on the maintenance of normal blood pressure in humans.
The Panel concludes that a cause and effect relationship has not been established between the consumption of EGCG in green tea (Camellia sinensis (L.) Kuntze) and the maintenance of a normal blood pressure.
Warunki i możliwe ograniczenia stosowania oświadczenia
Based on studies with green tea a daily intake of EGCG from green tea ranging from 69 to 657 mg can be regarded as adequate
