ID 1598 - Teanina z herbaty

PL: Teanina z herbaty
EN: L-theanine from Camellia sinensis (Common Name : Tea)
Pdf: L-theanine from Camellia sinensis

1. Charakterystyka żywności / składnika

The foods/food constituents that are the subject of the health claims are Camellia sinensis (L.) Kuntze (tea) and L-theanine.
Theanine ( -glutamylethylamide) is a glutamic acid analogue present mainly in the tea plant (Camellia sinensis), although its presence has also been reported in the mushroom Xerocomus basius. Theanine comprises 1-2 % of the dry weight of tea leaves. It is synthesised from glutamic acid and ethylamine in tea roots, and accounts for about 50 % of total amino acids in tea (Ekborg-Ott et al., 1997). L-theanine is a well characterised substance which can be measured by established methods.
The plant Camellia sinensis (L.) Kuntze is an evergreen shrub of the Theaceae family. Tea is an extract of the dried leaves of 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. Teas can be classified into three major types according to the different degrees of fermentation: green (un-fermented), oolong (semi-fermented) and black (fully fermented) (Wang et al., 2000).
The composition of tea drinks 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 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 or theogallin.
The Panel considers that while Camellia sinensis (L.) Kuntze (tea) is not sufficiently characterised in relation to the claimed effects, L-theanine from Camellia sinensis (L.) Kuntze (tea) is sufficiently characterised.

2.2. Łagodzenie stresu (ID 1598, 1601)

The claimed effects are “relaxation” and “neurological functions”. The Panel assumes that the target population is the general population.
In the context of the proposed wordings, clarifications from Member States and references provided, the Panel assumes that the claimed effects refer to alleviation of psychological stress.
Psychological stress can be measured by established methods.
The Panel considers that alleviation of psychological stress might be a beneficial physiological effect.

3. Naukowe uzasadnienia wpływu na zdrowie człowieka

The references provided included a report from an authoritative body on the effects of isolated L-theanine given at pharmacological doses, narrative reviews and monographs on the characterisation of the Camellia sinensis (L.) Kuntze plant and its byproducts, and a number of narrative reviews about the health effects of L-theanine. These publications did not contain original data which could be used for the scientific substantiation of the claims. A number of the references provided reported either on the effects of food constituents (e.g. caffeine and catechins) other than L-theanine, on the effects of L-theanine in combination with other food constituents (e.g. caffeine), or on health outcomes (e.g. anxiety, mood, brain chemistry, brain ischaemia, theanine bioavailability, theanine toxicity, hydration and cardiovascular health) other than the claimed effects. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claims.

3.2. Łagodzenie stresu (ID 1598, 1601)

Among the human studies provided, eight references were published in Japanese or Korean and a translation into an EU language was not available to the Panel. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claim.
Among the references provided were conference proceedings for which only the abstracts were available. The Panel notes that insufficient information was provided in these abstracts for a full scientific evaluation of the studies.
Two references investigated the effects of L-theanine consumption on brain electrical responses to cognitive tasks (Dimpfel et al., 2007; Gomez-Ramirez et al., 2007). The Panel notes that changes in brain electrical activity patterns are not considered to be a validated endpoint with respect to alleviation of psychological stress. The Panel considers that no conclusions can be drawn from these studies for the scientific substantiation of the claim.
In a randomised, double-blind, placebo-controlled, cross-over (Latin square design) intervention study, 16 healthy volunteers (age range: 18-34 years) received a benzodiazepine anxiolytic (alprazolam, 1 mg), L-theanine (200 mg) or placebo (unspecified) on three different testing days with a minimum wash-out period of seven days (Lu et al., 2004). Measures of anxiety (Beck anxiety inventory (BAI), Bond and Lader visual analogue mood scale (VAMS)) were obtained before the administration of the treatments, and 2.5 h and 5 h thereafter. The tests were undertaken at rest and also under experimentally induced anxiety conditions. The Panel notes that in the absence of direct measures of psychological stress, no conclusions can be drawn from measures of anxiety for the scientific substantiation of a claim on psychological stress. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claim.
Another randomised, double-blind, placebo-controlled, cross-over (Latin square design) study examined psychological and physiological responses to stress in 12 healthy male volunteers (age range: 20-25 years) after consumption of L-theanine (200 mg dissolved in 100 mL of water), placebo (water alone), or when receiving no treatment in four test sessions (Kimura et al., 2007). Each experimental session began with a 20 min rest period, followed by a mental arithmetic task for 20 min to induce stress, and then by two rest periods of 10 min. L-theanine was administered either at the beginning of the experiment (test 1) or immediately before the arithmetic task (test 2), whereas placebo was administered only at the beginning of the experiment (test 3). In an additional experimental session (test 4), no treatment was given and a rest period was substituted for the arithmetic task (control). At the end of each test session, subjective stress was measured using a visual analogue scale, and anxiety was evaluated with the state scale of the state-trait anxiety inventory
(STAI). Heart rate (measured continuously), heart rate variability (measured continuously) and saliva-IgA (obtained at the end of each test session) were also assessed. The Panel notes that the measure of psychological stress used in this study was unspecified, and that in the absence of direct measures of psychological stress no conclusions can be drawn from measures of anxiety for the scientific substantiation of a claim on psychological stress. The Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claim.
The Panel concludes that a cause and effect relationship has not been established between the consumption of L-theanine from Camellia Sinensis (L.) Kuntze (tea) and alleviation of psychological stress.

Warunki i możliwe ograniczenia stosowania oświadczenia

Recommended dosage: 50~250 mg JFFA approved for unlimited use in foods with the exception of infant foods. An amino acid from tea, present in the range of 4.30 mg to 24 mg per gram of tea. A cup of tea may contain 13.0 to 75.0 mg of theanine Safety studies such as 28 Day Subacute Toxicity Study, (2,000 mg/kg/day for 28 days) 78 Week Evaluation of Toxicity and Carcinogenicity Acute Toxicity/LD-50 Determination (5,000 mg/kg/day – 7 days) Ames Salmonella/Microsome Plate Test for Mutagenicity 2 week Dietary Range Finding Toxicity Study in Rats (6500 mg/kg/day) 13 week dietary toxicity and toxicokinetic study in rats (4000mg/kg/day), proved safety of L-theanine.

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