SCIENTIFIC OPINION. Black tea from Camellia sinensis and helps to focus attention

Transcription

1 The EFSA Journal (2008) 906, 1-10 SCIENTIFIC OPINION Black tea from Camellia sinensis and helps to focus attention Scientific substantiation of a health claim related to black tea from Camellia sinensis and helps to focus attention, pursuant to Article 13(5) of Regulation (EC) No 1924/ Scientific Opinion of the Panel on Dietetic Products, Nutrition and Allergies (Question No EFSA-Q ) Adopted on 4 December 2008 PANEL MEMBERS Jean-Louis Bresson, Albert Flynn, Marina Heinonen, Karin Hulshof, Hannu Korhonen, Pagona Lagiou, Martinus Løvik, Rosangela Marchelli, Ambroise Martin, Bevan Moseley, Andreu Palou, Hildegard Przyrembel, Seppo Salminen, Sean (J.J.) Strain, Stephan Strobel, Inge Tetens, Henk van den Berg, Hendrik van Loveren and Hans Verhagen. SUMMARY Following an application from Unilever PLC and Unilever NV submitted pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of The Netherlands, the Panel on Dietetic Products, Nutrition and Allergies was asked to deliver an opinion on the scientific substantiation of a health claim related to black tea from Camellia sinensis and helps to focus attention and enhances alertness. The scope of the application was proposed to fall under a health claim including a request for the protection of proprietary data. The food which is the subject of the claim is black tea from Camellia sinensis. The active constituents delivered in the tea infusion are purported to be caffeine and theanine. The Panel considers that the food which is the subject of the claim is sufficiently characterised. The health relationship as claimed by the applicant is that the consumption of black tea helps to focus attention and enhances alertness. The Panel considers that such a relationship combines 1 For citation purposes: Scientific Opinion of the Panel on Dietetic Products, Nutrition and Allergies on a request from Unilever PLC and Unilever NV on the scientific substantiation of a health claim related to black tea from Camellia sinensis and help focus attention. The EFSA Journal (2008) 906, 1-10 European Food Safety Authority, 2008

2 two separate claimed effects, i.e. attention and alertness. This opinion addresses the claimed effect related to attention. The target population is healthy adults, both men and women. The claimed effect helps you to focus attention is sufficiently defined and testable. The Panel considers that the claimed effect helps to focus attention might be beneficial for human health. Of the studies identified as pertinent by the applicant following the search of the literature, the Panel considers that 3 are of direct relevance to the claim. Two unpublished, proprietary, randomised, double-blind, placebo controlled and crossover-design experiments compared the effects of black tea to those of coloured/flavoured water. These experiments assessed attention using attention-switching and multisensory-attention tasks. While improvement in accuracy of response in both the multisensory-attention and attention-switching tasks was observed in experiment 1, there was no, or only marginal, improvement in accuracy in these tasks in experiment 2. For both tasks there was no consistent improvement in the response speed with tea compared to placebo in either experiment. The Panel notes the inconsistency in the findings between the two studies that were similar in design with only a small difference in cumulative dose for the purported active components (46 vs 36 mg theanine, 100 vs 90 mg caffeine). One proprietary study investigated the effects of drinks containing caffeine with or without theanine on behavioural measures of attention performance. These drinks tended to improve accuracy across the tasks but effects on reaction times were inconsistent. The cumulative doses of theanine and caffeine used in this study ( mg theanine, 147 mg caffeine) were higher than the cumulative doses in the conditions of use as proposed by the applicant (46 mg theanine and 100 mg caffeine from two to three typical cups of black tea). The Panel considers that this study provides only limited evidence to support the claimed effect of black tea under the conditions of use proposed by the applicant. The Panel concludes that the evidence provided is insufficient to establish a cause and effect relationship between the consumption of black tea from Camellia sinensis and helps to focus attention. Key words: black tea, caffeine, theanine, attention, alertness. The EFSA Journal (2008) 906, 2-10

3 TABLE OF CONTENTS Panel Members...1 Summary...1 Table of Contents...3 Background...4 Terms of reference...4 EFSA Disclaimer...4 Acknowledgements Information provided by the applicant Food/constituent as stated by the applicant Health relationship as claimed by the applicant Wording of the health claim as proposed by the applicant Specific conditions for use as proposed by the applicant Assessment Characterisation of food/constituent Relevance of the claimed effect to human health Scientific substantiation of the claimed effect...7 Conclusions...9 Documentation provided to EFSA...9 References...10 The EFSA Journal (2008) 906, 3-10

4 BACKGROUND Regulation (EC) No 1924/ harmonises the provisions that relate to nutrition and health claims and establishes rules governing the Community authorisation of health claims made on foods. As a rule, health claims are prohibited unless they comply with the general and specific requirements of that Regulation and are authorised in accordance with this Regulation and included in the lists of authorised claims provided for in Articles 13 and 14 thereof. In particular, Article 13(5) of that Regulation lays down provisions for addition of claims (other than those referring to the reduction of disease risk and to children s development and health), which are based on newly developed scientific evidence or include a request for the protection of proprietary data, to the Community list of permitted claims referred to in Article 13(3). According to Article 18 of that Regulation, an application for inclusion in the Community list of permitted claims referred to in Art 13(3) shall be submitted by the applicant to the national competent authority of a Member State, who will make the application and any supplementary information supplied by the applicant available to European Food Safety Authority (EFSA). Steps taken by EFSA: The application was received on 07/07/2008. The scope of the application was proposed to fall under a health claim including a request for the protection of proprietary data. The scientific evaluation procedure started on 07/07/2008. During the meeting on 4 December 2008, the NDA Panel, after having evaluated the overall data submitted, adopted an opinion on the scientific substantiation of a health claim related to black tea from Camellia sinensis and helps to focus attention. TERMS OF REFERENCE EFSA is requested to evaluate the scientific data submitted by the applicant in accordance with Article 16(3) of Regulation (EC) No 1924/2006. On the basis of that evaluation, EFSA will issue an opinion on the scientific substantiation of a health claim related to black tea from Camellia sinensis and helps to focus attention. EFSA DISCLAIMER The present opinion does not constitute, and cannot be construed as, an authorisation to the marketing of black tea from Camellia sinensis, a positive assessment of its safety, nor a decision on whether black tea from Camellia sinensis is, or is not, classified as a foodstuff. It should be noted that such an assessment is not foreseen in the framework of Regulation (EC) No 1924/2006. It should also be highlighted that the scope, the proposed wording of the claim and the conditions of use as proposed by the applicant may be subject to changes, pending the outcome of the authorisation procedure foreseen in Article 18(4) of Regulation (EC) No 1924/ European Parliament and Council (2006). Regulation (EC) No 1924/2006 of the European Parliament and of the Council of 20 December 2006 on nutrition and health claims made on foods. Official Journal of the European Union OJ L 404, Corrigendum OJ L 12, , p The EFSA Journal (2008) 906, 4-10

5 ACKNOWLEDGEMENTS The European Food Safety Authority wishes to thank Barbara Stewart-Knox and the members of the Working Group for the preparation of this opinion: Jean-Louis Bresson, Albert Flynn, Marina Heinonen, Hannu Korhonen, Ambroise Martin, Andreu Palou, Hildegard Przyrembel, Seppo Salminen, Sean (J.J.) Strain, Inge Tetens, Henk van den Berg, Hendrik van Loveren and Hans Verhagen. The EFSA Journal (2008) 906, 5-10

6 1. INFORMATION PROVIDED BY THE APPLICANT Applicant s name and address: Unilever PLC: Port Sunlight, Wirral, Merseyside, CH62 4ZD, UK. Unilever NV: Weena 455, Rotterdam, 3013 AL, The Netherlands. The application included a request for the protection of proprietary data in accordance with Article 21 of Regulation (EC) No 1924/ Food/constituent as stated by the applicant Black tea from Camellia sinensis Health relationship as claimed by the applicant Consumption of black tea is proposed to help to focus attention and enhance alertness through the action of caffeine and theanine. Focused attention is a cognitive process considered to be synonymous with concentration or mental focus and refers to the ability to select only relevant incoming sensory information Wording of the health claim as proposed by the applicant The applicant proposed the wording Black tea helps you to focus". Furthermore, the applicant proposed the following other possible examples of wording for the health claim: Black tea helps you to focus attention ; Black tea helps to clear your mind by improving concentration ; Black tea helps to clear your mind by helping you focus ; Black tea helps to clear your mind by helping you to focus your attention ; Black tea helps to gain mental clarity by helping to focus your attention ; Black tea helps you to switch attention ; Black tea helps you to be less distracted ; Black tea helps to give clarity of mind by helping you to focus attention ; Black tea helps you to feel alert ; Black tea helps you to concentrate ; Black tea helps you to be more accurate ; Black tea helps you to concentrate on the most important things ; Black tea gives the mental clarity by helping to focus attention ; Black tea may help me to think clearer because it helps me to focus on the relevant information ; Black tea helps you to focus so you have a less cluttered mind ; Black tea can help you think more clearly because it helps you focus Specific conditions for use as proposed by the applicant The target population as proposed by the applicant is healthy adults, both men and women. According to the applicant the effects of black tea on focusing attention and alertness have been observed with black tea providing a minimum cumulative dose of 46 mg L-theanine and 100 mg caffeine. Typically, these amounts of theanine and caffeine are delivered in two to three cups of tea depending on the specific characteristics of the particular tea. The EFSA Journal (2008) 906, 6-10

7 2. ASSESSMENT 2.1. Characterisation of food/constituent The food which is the subject of the claim is black tea from Camellia sinensis. The active constituents delivered in the tea infusion are purported to be caffeine and theanine (a non protein amino acid contained in tea). The applicant has provided a detailed account of the production and preparation process. Tea becomes unstable at moisture contents of 7% or above. In view of this potential problem, the production process ensures that the tea has low moisture content (< 5%) below which the product has good stability. Typically, dry tea leaves contain between 3-4% caffeine and % theanine. Assuming that a tea bag contains 2 g of tea, a 190 ml cup of black tea infused for between 3-5 minutes contains mg of caffeine and mg theanine. A controlled replicable method for preparing the tea infusion for research and claim purposes is specified. Data are presented which relate to the concentrations of caffeine and theanine in an infusion of commercial bags of black tea as used in the pertinent intervention studies. Sufficient evidence from proprietary data has also been provided for the bio-availability of caffeine and theanine. The Panel considers that the food which is the subject of the claim is sufficiently characterised Relevance of the claimed effect to human health The health relationship as claimed by the applicant is that the consumption of black tea helps to focus attention and enhances alertness. The Panel considers that such a relationship combines two separate claimed effects, i.e. attention and alertness. This opinion addresses the claimed effect related to attention. The target population is healthy adults, both men and women. The claimed effect helps you to focus attention is sufficiently defined and testable. The Panel considers that the claimed effect helps to focus attention might be beneficial for human health Scientific substantiation of the claimed effect The applicant performed a literature search using various combinations of the terms: tea, attention, alertness, cognition, and theanine, alone or in combination with caffeine, in PubMed, ERL WebSPIRS and Web of Science. A literature search on caffeine and attention was not carried out because of the well established effects of caffeine on attention and it appears that studies on the effects of caffeine (alone) on attention have not been included in the application. The Panel notes that, of the 14 studies cited by the applicant as pertinent to the claim, most of them have intervened with caffeine and/or L-theanine at concentrations which are substantially greater than those present in the commercial black tea product even if consumed at quantities of two to three cups (Bryan 2008; Gomez-Ramirez et al., in press (proprietary data) and 2007; Haskell et al., 2007; Kumagai et al., 2001; Ozeki et al., 2001; Parnell et al., 2006; Rogers et al., 2008). Three of the remaining studies were randomised cross-over studies which evaluated the effects of tea on end points that are not pertinent for a claim on attention (Hindmarch et al., 2000 and 1998; Quinlan et al., 2000). The EFSA Journal (2008) 906, 7-10

8 The Panel considers that 3 studies are of direct relevance to the claim black tea and helps to focus attention. Two unpublished, randomised, double-blind, placebo-controlled and crossover-design experiments (De Bruin et al., proprietary data, unpublished) compared the effects of black tea to those of coloured/flavoured water. All participants were in good health, non-smokers, not pregnant or breastfeeding and had a body mass index between 18 and 32 kg/m 2. They were all regular caffeine consumers (12.0 ± 5.4 and 10.7 ± 5.0 servings of tea/coffee/cola per week in experiment 1 and 2, respectively). Before starting the experiments participants consumed their normal breakfast and water, and had abstained from caffeinated and alcoholic beverages, caffeinated medications, and mushrooms since the previous night. Prior to testing participants were provided with a choice of standardised snacks and sandwiches, and were required to consume an identical meal on each visit. The experiments were designed to deliver a similar amount of caffeine and theanine; however, the cumulative amount of caffeine and theanine in the second study was slightly lower than in the first study. Each session was standardised and lasted approximately 2.5 hours in experiment 1 and 3 hours in experiment 2. The first experiment (De Bruin et al., proprietary data, unpublished) involved 26 participants (20 female, 6 male). This experiment assessed attention using attention-switching and multisensory-attention tasks. Treatments were allocated using a Latin Square design such that the order of treatments was counterbalanced across participants. Sessions were separated by at least 6 days and at most 14 days. The experiment compared black tea branded bags with placebo formulated with food colours and flavourings. Participants received two 200 ml servings of placebo or black tea (providing 50 mg caffeine and 23 mg theanine per 200 ml serving with a cumulative dose of 100 mg caffeine and 46 mg theanine). Following lunch, participants completed a set of tests (over a period of about 40 minutes) of cognitive performance to provide baseline values. On completion of the baseline tests, participants were given a ten minute break and provided with either one of the two test beverages: placebo or black tea, after the consumption of which they repeated the tests. A further identical drink was consumed (again, within ten minutes of completing the tests) and another set of tests completed. The participants, therefore, received two drinks and completed three test sessions per condition. The results of the multisensory-attention test showed that the proportion of correct responses was higher on both the multisensory auditory (p<0.001) and visual (p=0.03) attention subtasks in the tea condition relative to placebo. A marginally significant (P=0.043) improvement in response speed was reported for the multisensory-visual-attention subtask (response time data not provided) but not for the auditory-attention subtask. For the attentionswitching test, the proportion of correct responses was higher (2.3% more, where the overall average for correct responses for the two groups ranged from 85-90%) in the tea condition relative to placebo. The relevance of a difference of this magnitude between groups for percentage of correct responses was not reported. There was no difference in the response speed between the conditions. The second experiment (De Bruin et al., proprietary data, unpublished) involved 32 participants (15 female, 17 male). This experiment compared a commercial black tea product to coloured water, using the same set of tests as in the first experiment and with a similar protocol. Subjects received three 200 ml servings of placebo or black tea and completed 4 sets of tests. Tea provided about 30 mg caffeine and 12 mg theanine per 200 ml serving with a cumulative dose of 90 mg caffeine and 36 mg theanine. For the multisensory-attention test there were no differences in the number of correct responses or response speed between the tea and placebo conditions. For the attention-switching test, the proportion of correct responses was higher (1.6% more, where the overall average for correct responses for the two groups ranged from 92-95%) in the tea condition relative to placebo. The relevance of a difference of The EFSA Journal (2008) 906, 8-10

9 this magnitude between groups for percentage of correct responses was not reported. There was no difference in the response speed between the conditions. The Panel notes the inconsistency in the findings between the two studies that were similar in design with only a small difference in cumulative dose for the purported active components (46 vs 36 mg theanine, 100 vs 90 mg caffeine). A proprietary study commissioned by the applicant and conducted by Rao and Nobre (unpublished) investigated the effects of L-theanine combined with caffeine on behavioural measures of attention performance. In a cross-over design, 20 participants received 49 mg L- theanine combined with 49 mg caffeine, 23 mg L-theanine combined with 49 mg caffeine (ratio present in a cup of tea), 49 mg caffeine alone or placebo (containing approximately 5.27 mg of theanine and no caffeine). Participants were asked to refrain from drinking any beverages containing caffeine, including coffee, tea, cola or other soft drinks, chocolate (including any chocolate products) on the day of the experiment prior to arrival at the laboratory. Three cups of the test beverages were ingested over 80 minutes, each administration being separated by 40 minute intervals. Each session lasted approximately 3 hours. The respective cumulative doses for these three interventions were 147 mg caffeine and 147 mg theanine, 147 mg caffeine and 69 mg theanine, and 147 mg caffeine with no theanine. Behavioural measures of attention performance involved detecting and discriminating visual or auditory stimuli and making speeded motor responses. The caffeine and combined caffeine and L-theanine drinks tended to improve accuracy across the tasks but effects on reaction times were inconsistent. There was no evidence from this study that theanine at the doses used had any effect on attention separate to that of caffeine. The Panel notes that the cumulative doses of theanine and caffeine used in this study were higher than those used in experiment 1 from De Bruin et al. and were also higher that the cumulative doses in the conditions of use as proposed by the applicant. The Panel considers that this study provides only limited evidence to support the claimed effect of black tea under the conditions of use proposed by the applicant. The Panel concludes that the evidence provided is insufficient to establish a cause and effect relationship between the consumption of black tea from Camellia sinensis and helps to focus attention. CONCLUSIONS On the basis of data presented, the Panel concludes that: a) Black tea from Camellia sinensis which is the subject of the claim is sufficiently characterised. b) The target population is healthy adults. The claimed effect helps to focus attention might be beneficial for human health. c) The evidence provided is insufficient to establish a cause and effect relationship between the consumption of black tea from Camellia sinensis and helps to focus attention. DOCUMENTATION PROVIDED TO EFSA Health claim application on black tea from Camellia sinensis and helps to focus attention pursuant to Article 13(5) of Regulation (EC) No 1924/2006 (Claim Serial No: 0200_NL). July Submitted by Unilever PLC and Unilever NV. The EFSA Journal (2008) 906, 9-10

10 REFERENCES Bryan J. Psychological effects of dietary components of tea: caffeine and L-theanine, Nutr. Rev., 66(2): De Bruin EA, Rycroft JA, Owen GN, proprietary data, unpublished. Experiments 1 and 2: Black tea improves the ability to focus attention. Gomez-Ramirez M, Higgins BA, Rycroft JA, Owen GN, Mahoney J, Shpaner M, Foxe JJ, The deployment of intersensory selective attention: a high-density electrical mapping study of the effects of theanine. Clin. Neuropharmacology, 30(1), Gomez-Ramirez M, Kelly SP, Montesi JL, Foxe J, proprietary data, in press. Tea and human cognition I: The effects of L-theanine on alpha-band oscillatory brain activity during a visuo-spatial attention task. Haskell CF, Kennedy DO, Milne AL, Wesnes KA, ScholeyAB, The effects of L- theanine, caffeine and their combination on cognition and mood. Biol. Psychol. Feb;77(2): Epub 2007 Sep 26. Hindmarch I, Quinlan PT, Moore KL, Parkin C, The effects of black tea and other beverages on aspects of cognition and psychomotor performance. Psychopharmacology, 139, Hindmarch I, Rigney U, Stanley N, Quinlan PT, Rycroft J, Lane J, A naturalistic investigation of the effects of day-long consumption of tea, coffee and water on alertness, sleep onset and sleep quality. Psychopharmacology, 149, Kumagai T, Ozeki M, Okubo T, Juneja LR, Compositions for ameliorating attentiondeficient/hyperactivity disorder. EP A1. Ozeki M, Kumagai T, Okubo T, Juneja LR, Compositions for improving mental concentration. EP A1. Quinlan PT, Lane J, Moore KL, Aspen J, Rycroft JA, O Brien DC, The acute physiological and mood effects of tea and coffee: the role of caffeine level. Pharmacology Biochemistry and Behaviour, 66, Parnell H, Owen GN, Rycroft JA, Combined effects of L-theanine and caffeine on cognition and mood. Appetite, 47:273 Rao A and Nobre K, proprietary data, unpublished. The effects of theanine on attentional processes in the human brain. The 5th report to Unilever R&D. Rogers PJ, Smith JE, Heatherley SV, Pleydell-Pearce CW, Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology, 195(4), The EFSA Journal (2008) 906, 10-10