Scientific Opinion on the substantiation of health claims related to
Camellia sinensis (L.) Kuntze (tea), including catechins in green tea, and
improvement of endothelium-dependent vasodilation (ID 1106, 1310),
maintenance of normal blood pressure (ID 1310, 2657), maintenance of
normal blood glucose concentrations (ID 1108), maintenance of normal
blood LDL-cholesterol concentrations (ID 2640), protection of the skin
from UV-induced (including photo-oxidative) damage (ID 1110, 1119),
protection of DNA from oxidative damage (ID 1120, 1121), protection of
lipids from oxidative damage (ID 1275), contribution to normal cognitive
function (ID 1117, 2812), “cardiovascular system” (ID 2814), “invigoration
of the body” (ID 1274, 3280), decreasing potentially pathogenic gastro-
intestinal microorganisms (ID 1118), “immune health” (ID 1273) and
“mouth” (ID 2813) pursuant to Article 13(1) of Regulation (EC)
No 1924/2006[sup]1[/sup]
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)2, 3
European Food Safety Authority (EFSA), Parma, Italy
Słowa kluczowe:
Camellia sinensis
DNA
blood LDL-cholesterol
blood glucose concentrations
blood pressure
cardiovascular system
catechins
cognitive function
endothelium
gastro-intestinal microorganisms
health claims
immune health
invigoration of the body
lipids
mouth
oxidative damage
skin
vasodilation
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, green tea extract and epigallo-catechin-3-gallate (EGCG).
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. These teas 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 (Astill et al., 2001; Kaszkin et al., 2004). The degree 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 flavonoids, such as flavanols and flavandiols, 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 (Astill et al., 2001; Kaszkin et al., 2004). Tea extracts/infusions also contain variable amounts of potentially active food constituents, such as caffeine, theanine or theogallin. From the references provided it was not possible to characterise the specific green tea or green tea extract for which the claims are made.
Green tea catechins (including EGCG) can be measured in foods by established methods.
The Panel considers that whereas Camellia sinensis (L.) Kuntze (tea) and green tea extract are not sufficiently characterised in relation to the claimed effects, catechins in green tea (including EGCG) are sufficiently characterised.
2. Znaczenie oświadczenia dla zdrowia człowieka
2.1. Poprawa rozszerzenia naczyń krwionośnych zależnego od śródbłonka (ID 1106, 1310)
The claimed effects are “heart health” and “cardiovascular health”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings and the clarifications provided by Member States, the Panel assumes that the claimed effects refer to the improvement of endothelium-dependent vasodilation.
The Panel considers that a sustained improvement of endothelium-dependent vasodilation may be a beneficial physiological effect.
2.2. Utrzymanie prawidłowego ciśnienia tętniczego (ID 1310, 2657)
The claimed effects are “cardiovascular health” and “helps to keep elasticity of vessels”. The Panel assumes that the target population is the general population.
In the context of the proposed wording and the clarifications provided by Member States, the Panel assumes that the claimed effect refers to the maintenance of normal blood pressure.
A claim on EGCG in green tea (Camellia sinensis (L.) Kuntze) and maintenance of normal blood pressure has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010a) and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
2.3. Utrzymanie prawidłowego stężenia glukozy we krwi (ID 1108)
The claimed effect is “glucose metabolism”. The Panel assumes that the target population is the general population.
In the context of the proposed wording, the Panel assumes that the claimed effect refers to the maintenance of normal blood glucose concentrations.
A claim on catechins (including EGCG) from green tea (Camellia sinensis (L.) Kuntze) and the long-term maintenance of normal blood glucose concentrations has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010b), and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
2.4. Utrzymanie prawidłowego stężenia cholesterolu LDL we krwi (ID 2640)
The claimed effect is “helps to keep normal cholesterol levels”. The Panel assumes that the target population is the general population.
The Panel notes that the claimed effect refers to the maintenance of normal blood LDL-cholesterol concentrations.
A claim on catechins in green tea (Camellia sinensis (L.) Kuntze) and maintenance of normal blood cholesterol concentrations has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010a), and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
2.5. Ochrona skóry przed uszkodzeniem promieniami ultrafioletowymi (UV) (ID 1110, 1119)
The claimed effects are “skin health” and “skin care”. 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 protection of the skin from UV-induced damage, including photo-oxidative damage.
The Panel considers that protection of the skin from UV-induced (including photo-oxidative) damage is a beneficial physiological effect.
2.6. Ochrona DNA przed uszkodzeniem oksydacyjntm (ID 1120, 1121)
The claimed effects are “women health” and “male health/prostate health”. 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 protection of DNA (in breast, ovary and prostate cells) from oxidative damage caused by free radicals.
A claim on catechins (including EGCG) in green tea (Camellia sinensis (L.) Kuntze) and protection of DNA, proteins and lipids from oxidative damage has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010a). The references cited for this claim were in vitro, animal and human observational studies on the effects of tea, tea polyphenols and tea catechins on the prevention of carcinogenesis, and did not provide any additional scientific data which could be used to substantiate the claim.
2.7. Ochrona lipidów przed uszkodzeniem oksydacyjnym (ID 1275)
The claimed effect is “for heart health”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings and the clarifications provided by Member States, the Panel assumes that the claimed effect refers to the protection of lipids from oxidative damage caused by free radicals.
A claim on catechins (including EGCG) in green tea (Camellia sinensis (L.) Kuntze) and protection of DNA, proteins and lipids from oxidative damage has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010a), and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
2.8. Udział w prawidłowym przebiegu procesów poznawczych (ID 1117, 2812)
The claimed effects are “cognitive function”, and “mental state and performance”. The Panel assumes that the target population is the general population.
In the context of the proposed wording, the Panel assumes that the claimed effects refer to cognitive function.
Cognitive function includes memory, attention (concentration), learning, intelligence and problem solving, which are well defined constructs and can be measured by validated psychometric cognitive tests.
The Panel considers that contribution to normal cognitive function is a beneficial physiological effect.
2.9. Układ sercowo-naczyniowy (ID 2814)
The claimed effect is “cardiovascular system”. The Panel assumes that the target population is the general population.
The claimed effect is not sufficiently defined and no further details were provided in the proposed wording. No clarifications were provided by Member States.
The Panel considers that the claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
2.10. Ożywienie ciała (ID 1274, 3280)
The claimed effect is “invigoration of the body”. The Panel assumes that the target population is the general population.
The claimed effect is not sufficiently defined and no further details were provided in the proposed wording. No clarifications were provided by Member States.
The Panel considers that the claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
2.11. Zmniejszenie ilości potencjalnie patogennych mikroorganizmów przewodu pokarmowego (ID 1118)
The claimed effect is “colon health”. The Panel assumes that the target population is the general population.
In the context of the clarifications provided by Member States, the Panel assumes that the claimed effect refers to increasing the number of “beneficial” bacteria and decreasing the number of potentially pathogenic bacteria.
The numbers/proportions of bacterial groups that would constitute a “beneficial” intestinal/colon flora have not been established. Increasing the number of any groups of microorganisms is not in itself considered to be a beneficial physiological effect. The Panel considers that the evidence provided does not establish that increasing numbers of gastro-intestinal microorganisms is a beneficial physiological effect.
A claim on catechins in green tea (Camellia sinensis (L.) Kuntze) and decreasing potentially pathogenic intestinal microorganisms has already been assessed with an unfavourable outcome (EFSA Panel on Dietetic Products Nutrition and Allergies (NDA), 2010a), and the references cited for this claim did not provide any additional scientific data which could be used to substantiate the claim.
2.12. Odporność organizmu (ID 1273)
The claimed effect is “immune health”. The Panel assumes that the target population is the general population.
The claimed effect is not sufficiently defined and no further details were provided in the proposed wording or the clarifications provided by Member States. The references provided addressed several effect,s and it is not possible to establish which effect is the target for the claim. Given the multiple
roles of the immune system, the specific aspect of immune function that is the subject of the health claim needs to be specified, but it has not been indicated in the information provided.
The Panel considers that the claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
2.13. Usta (ID 2813)
The claimed effect is “mouth”. The Panel assumes that the target population is the general population.
The claimed effect is not sufficiently defined and no further details were provided in the proposed wording. No clarifications were provided by Member States.
The Panel considers that the claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka -
3.1. Poprawa rozszerzenia naczyń krwionośnych zależnego od śródbłonka (ID 1106, 1310)
The references provided for the substantiation of the claim included book chapters and narrative reviews that did not provide any original data that could be used for the scientific substantiation of the claimed effect. The references also included methodological studies on the analysis of tea polyphenols in urine and plasma, or on the determination of catechins in tea, as well as human intervention studies which assessed the effects of tea on health outcomes unrelated to the claimed effect (e.g. serum lipids, oxidative stress, hypertension and haemostasis), meta-analyses and human intervention studies on the effects of black tea or black tea flavonols (not further characterised) on different health outcomes, as well as cross-sectional and prospective cohort studies on the relationship between tea consumption (including green tea, but no further characterisation was provided) and chronic disease risk (e.g. coronary heart disease and stroke). The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
Among the human intervention studies which investigated the effects of green tea or green tea catechins on endothelium-dependent vasodilation (assessed as brachial-ankle pulse wave velocity, PWV), two were acute studies which did not address the sustained effects of chronic consumption of the food (Nagaya et al., 2004; Vlachopoulos et al., 2006), three s were uncontrolled (one arm) interventions (Kim et al., 2006; Murakami and Ohsato, 2003; Sung et al., 2005), and was a one randomised controlled trial (Ryu et al., 2006) in which green tea was not sufficiently characterised in relation to the claimed effect (e.g. amount of catechins not reported). The Panel considers that no conclusions can be drawn from these references 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) in green tea (Camellia sinensis (L.) Kuntze) and improvement of endothelium-dependent vasodilation.
3.2. Ochrona skóry przed uszkodzeniem promieniami ultrafioletowymi (UV) (ID 1110, 1119)
The references provided for the scientific substantiation of the claim included narrative reviews discussing the photoprotective effect of green tea polyphenols on human or animal skin tissues, which did not provide original data for the scientific substantiation of the claimed effect.
No human studies which addressed outcome measures related to the claimed effect following oral administration of the food which is the subject of the health claim were provided.
Animal and in vitro studies were also provided and reported on the effects of green tea catechins and other polyphenols, administered orally or topically: these studies addressed UV-radiation induced DNA damage in human leukocytes, or animal or human skin cancerogenesis, or monocytes from humans with skin cancer. The Panel considers that while effects shown in animal and in vitro studies may be used as supportive evidence, human studies are required for the substantiation of a claim, and that evidence provided in animal and in vitro studies alone is not sufficient to predict the occurrence of an effect of catechin consumption on protection of the skin from UV-induced (including photo- oxidative) damage in humans.
The Panel concludes that a cause and effect relationship has not been established between the consumption of catechins in green tea (Camellia sinensis (L.) Kuntze) and protection of the skin from UV-induced (including photo-oxidative) damage.
3.3. Udział w prawidłowym przebiegu procesów poznawczych (ID 1117, 2812)
Among the references provided to substantiate the claimed effect, a number of papers and monographs addressed the characterisation of Camellia sinensis (L.), tea infusions and tea catechins, and did not contain any primary data which could be used to substantiate the claimed effect. A number of the references cited reported on the effects of foods or food constituents other than catechins in green tea (e.g. caffeine, theanine, black tea preparations and pycnogenol). A large proportion of references reported on health outcomes other than the claimed effect (e.g. brain chemistry, brain electrical activity, subjective stress, mood, hydration status and Huntington's disease). The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
One cross-sectional study (Kuriyama et al., 2006) examined the association between green tea consumption and cognitive function in 1,003 Japanese subjects aged >70 years. The Panel notes that the catechin intake associated with green tea consumption was not reported. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
One study examined the effect of tea preparations (catechin content was not reported) on memory and brain morphology in mice (Chan et al., 2006). Two other studies in rodents examined the effects of green tea catechin administration on cognitive function measures (Haque et al., 2006; Unno et al., 2007). The Panel considers that evidence provided in animal studies is not sufficient to predict the occurrence of an effect of catechin consumption on cognitive function in humans.
The Panel concludes that a cause and effect relationship has not been established between the consumption of catechins in green tea (Camellia sinensis (L.) Kuntze) and contribution to normal cognitive function.
Wnioski
On the basis of the data presented, the Panel concludes that:
The food constituents, Camellia sinensis (L.) Kuntze (tea) and green tea extract, which are the subject of the health claims, are not sufficiently characterised in relation to the claimed effects, whereas catechins in green tea (including EGCG) are sufficiently characterised.
Improvement of endothelium-dependent vasodilation (ID 1106, 1310)
The claimed effects are “heart health” and “cardiovascular health”. The target population is assumed to be the general population. A sustained improvement of endothelium-dependent vasodilation may be a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of catechins (including EGCG) in green tea (Camellia sinensis (L.) Kuntze) and improvement of endothelium-dependent vasodilation.
Maintenance of normal blood pressure (ID 1310, 2657)
The claimed effects are “cardiovascular health” and “helps to keep elasticity of vessels”. The target population is assumed to be the general population. In the context of the proposed wording and the clarifications provided by Member States, it is assumed that the claimed effect refers to the maintenance of normal blood pressure.
A claim on EGCG in green tea (Camellia sinensis (L.) Kuntze) and maintenance of normal blood pressure has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data that could be used to substantiate the claim.
Maintenance of normal blood glucose concentrations (ID 1108)
The claimed effect is “glucose metabolism”. The target population is assumed to be the general population. In the context of the proposed wording, it is assumed that the claimed effect refers to the maintenance of normal blood glucose concentrations.
A claim on catechins (including EGCG) from green tea (Camellia sinensis (L.) Kuntze) and the long-term maintenance of normal blood glucose concentrations has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data that could be used to substantiate the claim.
Maintenance of normal blood LDL-cholesterol concentrations (ID 2640)
The claimed effect is “helps to keep normal cholesterol levels”. The target population is assumed to be the general population.
A claim on catechins in green tea (Camellia sinensis (L.) Kuntze) and maintenance of normal blood cholesterol concentrations has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data that could be used to substantiate the claim.
Protection of the skin from UV-induced (including photo-oxidative) damage (ID 1110, 1119)
The claimed effects are “skin health” and “skin care”. The target population is assumed to be the general population. In the context of the proposed wordings, it is assumed that the claimed effects refer to protection of the skin from UV-induced damage, including photo-oxidative damage. Protection of the skin from UV-induced (including photo-oxidative) damage is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of catechins in green tea (Camellia sinensis (L.) Kuntze) and protection of the skin from UV-induced (including photo-oxidative) damage.
Protection of DNA from oxidative damage (ID 1120, 1121)
The claimed effects are “women health” and “male health/prostate health”. The target population is assumed to be the general population. In the context of the proposed wordings, it is assumed that the claimed effects refer to protection of DNA (in breast, ovary and prostate cells) from oxidative damage caused by free radicals.
A claim on catechins (including EGCG) in green tea (Camellia sinensis (L.) Kuntze) and protection of DNA, proteins and lipids from oxidative damage has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data that could be used to substantiate the claim.
Protection of lipids from oxidative damage (ID 1275)
The claimed effect is “for heart health”. The target population is assumed to be the general population. In the context of the proposed wordings and the clarifications provided by Member States, it is assumed that the claimed effect refers to protection of lipids from oxidative damage caused by free radicals.
A claim on catechins (including EGCG) in green tea (Camellia sinensis (L.) Kuntze) and protection of DNA, proteins and lipids from oxidative damage has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data that could be used to substantiate the claim.
Contribution to normal cognitive function (ID 1117, 2812)
The claimed effect is “cognitive function”. The target population is assumed to be the general population. Contribution to normal cognitive function is a beneficial physiological effect.
A cause and effect relationship has not been established between the consumption of catechins in green tea (Camellia sinensis (L.) Kuntze) and contribution to normal cognitive function.
“Cardiovascular system” (ID 2814)
The claimed effect is “cardiovascular system”. The target population is assumed to be the general population.
The claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
“Invigoration of the body” (ID 1274, 3280)
The claimed effect is “invigoration of the body”. The target population is assumed to be the general population.
The claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
Decreasing potentially pathogenic gastro-intestinal microorganisms (ID 1118)
The claimed effect is “colon health”. The target population is assumed to be the general population. In the context of the clarifications provided by Member States, it is assumed that the claimed effect refers to increasing the number of “beneficial” bacteria and decreasing the
number of potentially pathogenic bacteria. The evidence provided does not establish that increasing numbers of gastro-intestinal microorganisms is a beneficial physiological effect.
A claim on catechins in green tea (Camellia sinensis (L.) Kuntze) and decreasing potentially pathogenic intestinal microorganisms has already been assessed with an unfavourable outcome, and the references cited for this claim did not provide any additional scientific data that could be used to substantiate the claim.
“Immune health” (ID 1273)
The claimed effect is “immune health”. The target population is assumed to be the general population.
The claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
“Mouth” (ID 2813)
The claimed effect is “mouth”. The target population is assumed to be the general population.
The claimed effect is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC) No 1924/2006.
