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Yilmaz U, Buzdagli Y, Polat ML, Bakir Y, Ozhanci B, Alkazan S, Ucar H. Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study. J Int Soc Sports Nutr 2023; 20:2267536. [PMID: 37815006 PMCID: PMC10566444 DOI: 10.1080/15502783.2023.2267536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 10/03/2023] [Indexed: 10/11/2023] Open
Abstract
PURPOSE Previous studies have investigated the effect of single or combined caffeine (CAF) and L-theanine (THE) intake on attention performance. However, its effect on shooting performance and cognitive performance in a sport is unknown. The aim of this study was to investigate the hypothesis "Does single or combined CAF and THE supplementation have an effect on shooting and cognitive performance in elite curling athletes?." It is predicted that over the next decade, studies based on nutritional ergogenic supplements in the developing sport of curling will continue to increase, leading to a significant increase in studies examining the effects of CAF and THE supplementation, alone or in combination, on throwing and cognitive performance in elite curling athletes. METHODS In this double-blind, randomized controlled crossover study, twenty-two elite national curling athletes (age 20.20 ± 1.61 and sports age 6.20 ± 0.51 years, height 174.10 ± 7.21 cm, BMI 21.80 ± 3.47 kg/m2) were randomly assigned to CAF (6 mg/kg single dose CAF), THE (6 mg/kg single dose THE), CAF*THE (6 mg/kg CAF and 6 mg/kg THE combined) and PLA (400 mg maltodextrin) groups at each of four sessions. 60 minutes after taking the supplement, the athletes were first given the Stroop test and then asked to shoot. RESULTS Our main findings have shown that the performance of athletes in guard (F=3.452, P < .001, ηp2 = .842), draw (F=1.647, P < .001, ηp2 = .485), and take-out (F=3.121, P < .001, ηp2 = .743) shot styles significantly improved when comparing the combined intake of CAF and THE to the PLA. Regarding cognitive performance evaluation through the Stroop test, during the NR task (F=4.743, P = .001, ηp2 = .653), the combined intake of CAF and THE significantly improved reaction times compared to the intake of single CAF, THE, or PLA. The best reaction times during the CR and ICR (respectively; F=2.742, P = .004, ηp2 = .328; F = 1.632, P < .001, ηp2 = .625) tasks were achieved with the combined CAF and THE intake, showing a significant improvement compared to PLA. During the NER (F=2.961, P < .001, ηp2 = .741), task, the combined intake of CAF and THE significantly improved error rates compared to the intake of CAF, THE, or PLA single. The best accuracy rates during the CER and ICER (respectively; F=4.127, P < .001, ηp2 = .396; F=3.899, P < .001, ηp2 = .710) tasks were achieved with the combined CAF and THE intake, leading to a significant reduction in error rates compared to PLA. Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. CONCLUSIONS Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. The combined use of these supplements has been found to be more effective on shooting and cognitive performance than their single use.
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Affiliation(s)
- Umut Yilmaz
- Hakkâri University, Department of Physical Education and Sports, Faculty of Education, Hakkâri, Turkey
| | - Yusuf Buzdagli
- Erzurum Technical University, Department of Coaching Education, Faculty of Sport Sciences, Erzurum, Turkey
| | | | - Yusuf Bakir
- Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey
| | - Burak Ozhanci
- Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey
| | - Sena Alkazan
- Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey
| | - Halil Ucar
- Atatürk University, Institute of Winter Sports and Sport Sciences, Erzurum, Turkey
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Dassanayake TL, Wijesundara D, Kahathuduwa CN, Weerasinghe VS. Dose-response effect of L-theanine on psychomotor speed, sustained attention, and inhibitory control: a double-blind, placebo-controlled, crossover study. Nutr Neurosci 2023; 26:1138-1146. [PMID: 36263942 DOI: 10.1080/1028415x.2022.2136884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND L-theanine is a non-protein-forming amino acid found in tea. Previous research shows high doses (100-400 mg) of L-theanine enhances attention, mainly by reducing mind wandering and distracter processing. We hypothesized that these indirect mechanisms could significantly improve the performance of low-level attentional tasks, whereas the relative contribution could be less in complex attentional tasks that require active, higher-order processing of target stimuli. METHODS To test this hypothesis, we conducted a double-blind, placebo-controlled, counterbalanced, four-way crossover study in 32 healthy young adults, where we compared the effects of three doses of L-theanine (100, 200 and 400 mg) with a placebo (distilled water), administered before and 50 min after dosing, on three attentional tasks from the Cambridge Neuropsychological Test Automated Battery [viz. Reaction Time (RTI)-visuomotor speed, Rapid Visual Information Processing (RVP)-sustained attention, and Stop Signal Task (SST)-inhibitory control]. Results were analyzed in dose × time repeated measures ANOVA models, with subsequent pairwise comparisons. RESULTS Active doses significantly improved reaction times in the RTI (100-200 mg) and RVP (200-400 mg) tasks from baseline (p < 0.05), but once controlled for the change-from-baseline caused by placebo, only the RTI simple reaction times showed significant improvements, following 100 mg (Δ = 16.3 ms, p = 0.009) and 200 mg (Δ = 16.9 ms, p = 0.009) of L-theanine. CONCLUSIONS Consistent with our hypothesis, these findings suggest that L-theanine significantly improves attention in simple visuomotor tasks, but not in more complex sustained attention tasks, or executive control tasks that require top-down inhibition of pre-active responses.
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Affiliation(s)
- Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
- School of Psychological Sciences, The University of Newcastle, Callaghan, Australia
| | - Devasmitha Wijesundara
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Chanaka N Kahathuduwa
- Department of Psychiatry, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
- Department of Laboratory Science and Primary Care, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Vajira S Weerasinghe
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
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Maciejewska K, Moczarska W. Single Dose of an Energy Dietary Supplement with a Small Amount of Caffeine Prevents an Increase of a Low Frequency Resting State EEG in Possible Mental Fatigue. Neuroscience 2023; 527:1-10. [PMID: 37437800 DOI: 10.1016/j.neuroscience.2023.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 06/26/2023] [Accepted: 07/05/2023] [Indexed: 07/14/2023]
Abstract
Due to the increasing needs to enhance our cognitive performance, and decrease fatigue with increasing number of tasks in our everyday life, it's interesting to study whether a small amount of active substance present in dietary supplements, is enough to impact cognition. We investigated an acute effect of an energy dietary supplement containing low amount of caffeine (55 mg) and other stimulatory ingredients by means of a resting state EEG in a double blind, placebo controlled study (N = 47, 27 women). The use of a nonparametric cluster-based permutation analysis allowed us to observed a significant group × block interaction effect after 90 minutes post-ingestion (P = 0.022 cluster corrected) in the 'eyes closed' condition, i.e. an increase in normalized rsEEG power in the placebo group, which was abolished in the study group. This difference corresponded to a broad spatio-spectral cluster between around 6.5 Hz and 10.5 Hz (i.e. high theta and low alpha band) maximal over centro-temporo-parieto-occipital scalp areas. Similar trend but without significant effect was found in the 'eyes open' condition. Our results suggest that low caffeine content dietary supplementation acts as a reversal of the fatigue-related brain activity in the neural networks active in the resting state. These findings not only may help to clarify previous nonconclusive findings, but more importantly, show that an ingestion of caffeinated stimulants before neurocognitive examinations, both in research and diagnostics, should be taken into account, as they may influence cognition, even in small doses and when the effects are absent in the behavioral measures.
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Affiliation(s)
- Karina Maciejewska
- University of Silesia in Katowice, Faculty of Science and Technology, Institute of Biomedical Engineering, Poland.
| | - Wiktoria Moczarska
- College of Interdisciplinary Studies at the University of Silesia in Katowice, Poland
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Medrano M, Molina-Hidalgo C, Alcantara JMA, Ruiz JR, Jurado-Fasoli L. Acute Effect of a Dietary Multi-Ingredient Nootropic as a Cognitive Enhancer in Young Healthy Adults: A Randomized, Triple-Blinded, Placebo-Controlled, Crossover Trial. Front Nutr 2022; 9:858910. [PMID: 35634417 PMCID: PMC9133906 DOI: 10.3389/fnut.2022.858910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Aim To study the acute effect of a dietary multi-ingredient nootropic on cognitive performance in young healthy adults. We also analyzed the influence of the dietary multi-ingredient nootropic on emotional state, heart rate (HR), and heart rate variability (HRV). Methods This is a randomized, triple-blinded, placebo-controlled, crossover trial. In total, 26 young healthy adults (50% women; 24.9 ± 3.3 years old) ingested 10 g of a dietary multi-ingredient nootropic [Evo-Gamers®; Harrison Sport Nutrition (HSN), Granada, Spain] or placebo (maltodextrin) in a randomized order (clinicaltrials.gov No. NCT04790188). After 30 min of the ingestion, participants performed a battery of cognitive performance tests to measure the processing speed, inhibitory control, working memory, cognitive flexibility, creativity, and verbal fluency. The emotional status was assessed through questionnaires, and HR and HRV were measured using a heart rate monitor. Results In comparison with placebo, the acute ingestion of the nootropic showed a significantly better response time in several cognitive tests (i.e., processing speed, inhibitory control, spatial working memory, and cognitive flexibility, all P < 0.05 and effect size range of 0.4–0.6). It also displayed a higher accuracy in the processing speed, the inhibitory control, and cognitive flexibility tests (all P < 0.05; effect size ranged from 0.4 to 0.6). Furthermore, the nootropic showed a higher creativity and positive emotions and lower sadness-depression emotions, whereas HR and HRV remained similar between placebo vs. nootropic conditions. However, there were no differences between the nootropic and placebo in verbal fluency, motivation, or anxiety (all P > 0.05). Conclusion An acute ingestion of a dietary multi-ingredient nootropic enhances cognitive performance in comparison with placebo without negatively influencing HR or HRV in young healthy adults.
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Affiliation(s)
- María Medrano
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
| | - Cristina Molina-Hidalgo
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
- Department of Physiology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Juan M. A. Alcantara
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
| | - Jonatan R. Ruiz
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria, ibs.Granada, Granada, Spain
| | - Lucas Jurado-Fasoli
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
- Department of Physiology, Faculty of Medicine, University of Granada, Granada, Spain
- *Correspondence: Lucas Jurado-Fasoli,
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Ni AM, Bowes BS, Ruff DA, Cohen MR. Methylphenidate as a causal test of translational and basic neural coding hypotheses. Proc Natl Acad Sci U S A 2022; 119:e2120529119. [PMID: 35467980 PMCID: PMC9169912 DOI: 10.1073/pnas.2120529119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 03/17/2022] [Indexed: 11/18/2022] Open
Abstract
Most systems neuroscience studies fall into one of two categories: basic science work aimed at understanding the relationship between neurons and behavior, or translational work aimed at developing treatments for neuropsychiatric disorders. Here we use these two approaches to inform and enhance each other. Our study both tests hypotheses about basic science neural coding principles and elucidates the neuronal mechanisms underlying clinically relevant behavioral effects of systemically administered methylphenidate (Ritalin). We discovered that orally administered methylphenidate, used clinically to treat attention deficit hyperactivity disorder (ADHD) and generally to enhance cognition, increases spatially selective visual attention, enhancing visual performance at only the attended location. Further, we found that this causal manipulation enhances vision in rhesus macaques specifically when it decreases the mean correlated variability of neurons in visual area V4. Our findings demonstrate that the visual system is a platform for understanding the neural underpinnings of both complex cognitive processes (basic science) and neuropsychiatric disorders (translation). Addressing basic science hypotheses, our results are consistent with a scenario in which methylphenidate has cognitively specific effects by working through naturally selective cognitive mechanisms. Clinically, our findings suggest that the often staggeringly specific symptoms of neuropsychiatric disorders may be caused and treated by leveraging general mechanisms.
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Affiliation(s)
- Amy M. Ni
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260
| | - Brittany S. Bowes
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260
| | - Douglas A. Ruff
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260
| | - Marlene R. Cohen
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260
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Dassanayake TL, Kahathuduwa CN, Weerasinghe VS. L-theanine improves neurophysiological measures of attention in a dose-dependent manner: a double-blind, placebo-controlled, crossover study. Nutr Neurosci 2022; 25:698-708. [PMID: 32777998 DOI: 10.1080/1028415x.2020.1804098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Objective: L-theanine, a non-proteinic amino acid found in tea, is known to enhance attention particularly in high doses, with no reported adverse effects. We aimed to determine whether oral administration of L-theanine acutely enhances neurophysiological measures of selective attention in a dose-dependent manner.Methods: In a double-blind, placebo-controlled, counterbalanced, 4-way crossover study in a group of 27 healthy young adults, we compared the effects of 3 doses of L-theanine (100, 200 and 400 mg) with a placebo (distilled water) on latencies of amplitudes of attentive and pre-attentive cognitive event-related potentials (ERPs) recorded in an auditory stimulus discrimination task, before and 50 min after dosing.Results: Compared to the placebo, 400 mg of theanine showed a significant reduction in the latency of the parietal P3b ERP component (p < 0.05), whereas no significant changes were observed with lower doses. A subsequent exploratory regression showed that each 100-mg increase in dose reduces the P3b latency by 4 ms (p < 0.05). No dose-response effect was observed in P3b amplitude, pre-attentive ERP components or reaction time.Discussion: The findings indicate L-theanine can increase attentional processing of auditory information in a dose-dependent manner. The linear dose-response attentional effects we observed warrant further studies with higher doses of L-theanine.
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Affiliation(s)
- Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.,School of Psychology, The University of Newcastle, Callaghan, Australia
| | - Chanaka N Kahathuduwa
- Department of Psychiatry, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Department of Laboratory Science and Primary Care, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Vajira S Weerasinghe
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
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Effect of Extraction Methodology on the Phytochemical Composition for Camelia sinensis “Powdered Tea Extracts” from Different Provenances. BEVERAGES 2022. [DOI: 10.3390/beverages8010013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
(1) Background: beverages based on extracts from Camellia sinensis are popular worldwide. Due to an increasing number of processed teas on the market, there is a need to develop unified classification standards based on chemical analysis. Meanwhile, phytochemical characterizations are mainly performed on tea samples from China (~80%). Hence, data on teas of other provenances is recommended. (2) Methods: in the present investigation, we characterized lyophilised extracts obtained by infusion, maceration and methanolic extraction derived from tea samples from China, Japan, Sri Lanka and Portugal by phytochemistry (catechins, oxyaromatic acids, flavonols, alkaloids and theanine). The real benefits of drinking the tea were analysed based on the bioavailability of the determined phytochemicals. (3) Results: the infusions revealed the highest total phenolic contents (TPC) amounts, while methanolic extracts yielded the lowest. The correlation matrix indicated that the levels of phenolic compounds were similar in the infusions and methanolic samples, while extractions made by maceration were significantly different. The differences could be partially explained by the different amounts of (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and gallic acids (GA). The catechin percentages were significantly lower in the macerations, especially the quantity of EGCG decreases by 4- to 5-fold after this process. (4) Conclusions: the results highlight the importance of the processing methodology to obtain “instant tea”; the composition of the extracts obtained with the same methodology is not significantly affected by the provenance of the tea. However, attention should be drawn to the specificities of the Japanese samples (the tea analysed in the present work was of Sencha quality). In contrast, the extraction methodology significantly affects the phytochemical composition, especially concerning the content of polyphenols. As such, our results indicate that instant tea classification based on chemical composition is sensible, but there is a need for a standard extraction methodology, namely concerning the temperature and time of contact of the tea leaves with the extraction solvent.
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Lorca C, Mulet M, Arévalo-Caro C, Sanchez MÁ, Perez A, Perrino M, Bach-Faig A, Aguilar-Martínez A, Vilella E, Gallart-Palau X, Serra A. Plant-derived nootropics and human cognition: A systematic review. Crit Rev Food Sci Nutr 2022; 63:5521-5545. [PMID: 34978226 DOI: 10.1080/10408398.2021.2021137] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Substances with modulatory capabilities on certain aspects of human cognition have been revered as nootropics from the dawn of time. The plant kingdom provides most of the currently available nootropics of natural origin. Here, in this systematic review, we aim to provide state-of-the-art information regarding proven and unproven effects of plant-derived nootropics (PDNs) on human cognition in conditions of health and disease. Six independent searches, one for each neurocognitive domain (NCD), were performed in parallel using three independent scientific library databases: PubMed, Cochrane and Scopus. Only scientific studies and systematic reviews with humans published between January 2000 and November 2021 were reviewed, and 256 papers were included. Ginkgo biloba was the most relevant nootropic regarding perceptual and motor functions. Bacopa monnieri improves language, learning and memory. Withania somnifera (Ashwagandha) modulates anxiety and social-related cognitions. Caffeine enhances attention and executive functions. Together, the results from the compiled studies highlight the nootropic effects and the inconsistencies regarding PDNs that require further research.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.2021137.
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Affiliation(s)
- Cristina Lorca
- IMDEA-Food Research Institute, +Pec Proteomics, Campus of International Excellence UAM + CSIC, Old Cantoblanco Hospital, Madrid, Spain
- Biomedical Research Institute of Lleida Dr. Pifarré Foundation (IRB Lleida) - Neuroscience Area - University Hospital Arnau de Vilanova (HUAV) - School of Medicine, University of Lleida (UdL), Lleida, Spain
- Proteored - Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - María Mulet
- Biomedical Research Institute of Lleida Dr. Pifarré Foundation (IRB Lleida) - Neuroscience Area - University Hospital Arnau de Vilanova (HUAV) - School of Medicine, University of Lleida (UdL), Lleida, Spain
| | - Catalina Arévalo-Caro
- Biomedical Research Institute of Lleida Dr. Pifarré Foundation (IRB Lleida) - Neuroscience Area - University Hospital Arnau de Vilanova (HUAV) - School of Medicine, University of Lleida (UdL), Lleida, Spain
| | - M Ángeles Sanchez
- IMDEA-Food Research Institute, +Pec Proteomics, Campus of International Excellence UAM + CSIC, Old Cantoblanco Hospital, Madrid, Spain
| | - Ainhoa Perez
- IMDEA-Food Research Institute, +Pec Proteomics, Campus of International Excellence UAM + CSIC, Old Cantoblanco Hospital, Madrid, Spain
| | - María Perrino
- IMDEA-Food Research Institute, +Pec Proteomics, Campus of International Excellence UAM + CSIC, Old Cantoblanco Hospital, Madrid, Spain
| | - Anna Bach-Faig
- FoodLab Research Group (2017SGR 83), Faculty of Health Sciences, Open University of Catalonia (UOC), Barcelona, Spain
- Food and Nutrition Area, Barcelona Official College of Pharmacists, Barcelona, Spain
| | - Alicia Aguilar-Martínez
- FoodLab Research Group (2017SGR 83), Faculty of Health Sciences, Open University of Catalonia (UOC), Barcelona, Spain
| | - Elisabet Vilella
- Hospital Universitari Institut Pere Mata (HUIPM), Institut Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
- Universitat Rovira i Virgili (URV), Reus, Spain
- Centro de investigación Biomédica en Salud Mental CIBERSAM, Instituto de Salud Carlos III, Madrid, Spain
| | - Xavier Gallart-Palau
- Biomedical Research Institute of Lleida Dr. Pifarré Foundation (IRB Lleida) - Neuroscience Area - University Hospital Arnau de Vilanova (HUAV) - School of Medicine, University of Lleida (UdL), Lleida, Spain
- Proteored - Instituto de Salud Carlos III (ISCIII), Madrid, Spain
- Hospital Universitari Institut Pere Mata (HUIPM), Institut Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
- Centro de investigación Biomédica en Salud Mental CIBERSAM, Instituto de Salud Carlos III, Madrid, Spain
| | - Aida Serra
- IMDEA-Food Research Institute, +Pec Proteomics, Campus of International Excellence UAM + CSIC, Old Cantoblanco Hospital, Madrid, Spain
- Biomedical Research Institute of Lleida Dr. Pifarré Foundation (IRB Lleida) - Neuroscience Area - University Hospital Arnau de Vilanova (HUAV) - School of Medicine, University of Lleida (UdL), Lleida, Spain
- Proteored - Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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Jiang Y, Huang Y, Wu Y, Wang L. Drinking tea improves the convergent creativity performance. Food Qual Prefer 2022. [DOI: 10.1016/j.foodqual.2021.104360] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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10
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Owolabi JO, Adefule KA, Shallie PD, Fabiyi OS, Olatunji SY, Olanrewaju JA, Ajibade TP, Oyewumi S, Ogunnaike PO. Experimental study of pre- and postnatal caffeine exposure and its observable effects on selected neurotransmitters and behavioural attributes at puberty : Caffeine exposure and its observable effects on selected neurotranmitters and behaviour. Metab Brain Dis 2021; 36:2029-2046. [PMID: 34460045 DOI: 10.1007/s11011-021-00829-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 08/21/2021] [Indexed: 10/20/2022]
Abstract
Caffeine is globally consumed as a stimulant in beverages. It is also ingested in purified forms as power and tablets. Concerns have been raised about the potential consequences of intrauterine and early life caffeine exposure on brain health. This study modeled caffeine exposure during pregnancy and early postanal life until puberty, and the potential consequences. Caffeine powder was dissolved in distilled water. Thirty-two (n = 32) pregnant mice (Mus musculus) (dams) were divided into four groups- A, B, C and D. Group A animals served as a control, receiving placebo. Caffeine doses in mg/kg body weight were administered as follows: Group B, 10 mg/kg; Group C, 50 mg/kg; Group D, 120 mg/kg. Prenatal caffeine exposure [phase I] lasted throughout pregnancy. Half the number of offspring (pups) were sacrificed at birth; the rest were recruited into phase II and the experiment continued till day 35, marking puberty. Brain samples were processed following sacrifice. γ-aminobutyric acid (GABA), acetylcholine (ACh), and serotonin (5Ht) neurotransmitters were assayed in homogenates to evaluate functional neurochemistry. Anxiety and memory as neurobehavioural attributes were observed using the elevated plus and Barnes' mazes respectively. Continuous caffeine exposure produced positive effects on short and long-term memory parameters; the pattern interestingly was irregular and appeared more effective with the lowest experimental dose. Anxiety test results showed no attributable significant aberrations. Caffeine exposure persistently altered the neurochemistry of selected neurotransmitters including ACh and 5Ht, including when exposure lasted only during pregnancy. ACh significantly increased in group BC+ to 0.3475μgg-1 relative to control's 0.2508μgg-1; pre-and continuous postnatal exposure in Group B increased 5Ht to 0.2203 μgg-1 and 0.2213 μgg-1 respectively relative to control's 0.1863 μgg-1. From the current investigation, caffeine exposure in pregnancy had persistent effects on brain functional attributes including neurotransmitters activities, memory and anxiety. Caffeine in moderate doses affected memory positively but produced negative effects at the higher dosage including increased anxiety tendencies.
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Affiliation(s)
- Joshua O Owolabi
- Department of Anatomy, Babcock University, Ilishan-Remo, Nigeria.
- Department of Anatomy, Univerity of Global Health Equity, Kigali, Rwanda.
| | - Kehinde A Adefule
- Department of Anatomy, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
| | - Philemon D Shallie
- Department of Anatomy, Babcock University, Ilishan-Remo, Nigeria
- Department of Anatomy, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
| | - Oluseyi S Fabiyi
- Department of Anatomy, Babcock University, Ilishan-Remo, Nigeria
| | | | | | | | - Samson Oyewumi
- Department of Anatomy, Babcock University, Ilishan-Remo, Nigeria
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Effects of Daily Matcha and Caffeine Intake on Mild Acute Psychological Stress-Related Cognitive Function in Middle-Aged and Older Adults: A Randomized Placebo-Controlled Study. Nutrients 2021; 13:nu13051700. [PMID: 34067795 PMCID: PMC8156288 DOI: 10.3390/nu13051700] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 01/26/2023] Open
Abstract
Matcha, a type of green tea, has a higher amino acid content than other types of tea. We previously examined the ability of matcha to improve cognitive function in older adults and determined that continuous matcha intake improves attention and executive function. This study aimed to compare the effects of matcha and caffeine and clarify the differences between these effects. The study was registered at the University Hospital Medical Information Network (UMIN000036578). The effect of single and continuous intake was compared, and the usefulness of continuous intake was evaluated under the stress condition. The Uchida-Kraepelin test (UKT) was used to induce mild acute stress, and the Cognitrax was used to evaluate cognitive function. A single dose of caffeine improved attentional function during or after stress loading. The reduced reaction time in the Cognitrax, observed following a single dose of matcha, was likely due to caffeine. The matcha group showed an increase in the amount of work after continuous intake, whereas the caffeine group only showed an increase in the amount of work for the UKT after a single dose. Ingesting matcha with caffeine improves both attention and work performance when suffering from psychological stress compared with caffeine alone.
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Christensen ZP, Freedman EG, Foxe JJ. Caffeine exposure in utero is associated with structural brain alterations and deleterious neurocognitive outcomes in 9-10 year old children. Neuropharmacology 2021; 186:108479. [PMID: 33529676 DOI: 10.1016/j.neuropharm.2021.108479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/22/2021] [Accepted: 01/27/2021] [Indexed: 01/17/2023]
Abstract
Caffeine, a very widely used and potent neuromodulator, easily crosses the placental barrier, but relatively little is known about the long-term impact of gestational caffeine exposure (GCE) on neurodevelopment. Here, we leverage magnetic resonance imaging (MRI) data, collected from a very large sample of 9157 children, aged 9-10 years, as part of the Adolescent Brain and Cognitive Developmentsm (ABCD ®) study, to investigate brain structural outcomes at 27 major fiber tracts as a function of GCE. Significant relationships between GCE and fractional anisotropy (FA) measures in the inferior fronto-occipito fasciculus and corticospinal tract of the left hemisphere (IFOF-LH; CST-LH) were detected via mixed effects binomial regression. We further investigated the interaction between these fiber tracts, GCE, cognitive measures (working memory, task efficiency), and psychopathology measures (externalization, internalization, somatization, and neurodevelopment). GCE was associated with poorer outcomes on all measures of psychopathology but had negligible effect on cognitive measures. Higher FA values in both fiber tracts were associated with decreased neurodevelopmental problems and improved performance on both cognitive tasks. We also identified a decreased association between FA in the CST-LH and task efficiency in the GCE group. These findings suggest that GCE can lead to future neurodevelopmental complications and that this occurs, in part, through alteration of the microstructure of critical fiber tracts such as the IFOF-LH and CST-LH. These data suggest that current guidelines regarding limiting caffeine intake during pregnancy may require some recalibration.
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Affiliation(s)
- Zachary P Christensen
- The Cognitive Neurophysiology Laboratory, The Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Edward G Freedman
- The Cognitive Neurophysiology Laboratory, The Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, The Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA.
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13
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Kahathuduwa CN, Wakefield S, West BD, Blume J, Dassanayake TL, Weerasinghe VS, Mastergeorge A. Effects of L-theanine-caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT. Sci Rep 2020; 10:13072. [PMID: 32753637 PMCID: PMC7403383 DOI: 10.1038/s41598-020-70037-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/21/2020] [Indexed: 01/01/2023] Open
Abstract
We examined the acute effects of L-theanine, caffeine and their combination on sustained attention, inhibitory control and overall cognition in boys with attention deficit hyperactivity disorder (ADHD). L-Theanine (2.5 mg/kg), caffeine (2.0 mg/kg), their combination and a placebo were administered in a randomized four-way repeated-measures crossover with washout, to five boys (8-15 years) with ADHD. Functional magnetic resonance imaging (fMRI) was performed during a Go/NoGo task and a Stop-signal task ~ 1 h post-dose. NIH Cognition Toolbox was administered ~ 2 h post-dose. Treatment vs. placebo effects were examined in multi-level mixed-effects models. L-Theanine improved total cognition composite in NIH Cognition Toolbox (p = 0.040) vs. placebo. Caffeine worsened and L-theanine had a trend of worsening inhibitory control (i.e. increased Stop-signal reaction time; p = 0.031 and p = 0.053 respectively). L-Theanine-caffeine combination improved total cognition composite (p = 0.041), d-prime in the Go/NoGo task (p = 0.033) and showed a trend of improvement of inhibitory control (p = 0.080). L-Theanine-caffeine combination was associated with decreased task-related reactivity of a brain network associated with mind wandering (i.e. default mode network). L-Theanine-caffeine combination may be a potential therapeutic option for ADHD-associated impairments in sustained attention, inhibitory control and overall cognitive performance.
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Affiliation(s)
- Chanaka N Kahathuduwa
- Department of Laboratory Sciences and Primary Care, School of Health Professions, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, USA.
- Department of Psychiatry, School of Medicine, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, USA.
- Department of Human Development and Family Studies, College of Human Sciences, Texas Tech University, Lubbock, TX, USA.
| | - Sarah Wakefield
- Department of Psychiatry, School of Medicine, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, USA
- Department of Human Development and Family Studies, College of Human Sciences, Texas Tech University, Lubbock, TX, USA
| | - Blake D West
- Department of Human Development and Family Studies, College of Human Sciences, Texas Tech University, Lubbock, TX, USA
| | - Jessica Blume
- Department of Human Development and Family Studies, College of Human Sciences, Texas Tech University, Lubbock, TX, USA
| | - Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
- School of Psychology, The University of Newcastle, Callaghan, NSW, Australia
| | - Vajira S Weerasinghe
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Ann Mastergeorge
- Department of Human Development and Family Studies, College of Human Sciences, Texas Tech University, Lubbock, TX, USA
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Li J, Romero-Garcia R, Suckling J, Feng L. Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation. Aging (Albany NY) 2019; 11:3876-3890. [PMID: 31209186 PMCID: PMC6594801 DOI: 10.18632/aging.102023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/09/2019] [Indexed: 12/15/2022]
Abstract
The majority of tea studies have relied on neuropsychological measures, and much fewer on neuroimaging measures, especially for interregional connections. To date, there has been no exploration of the effect of tea on system-level brain networks. We recruited healthy older participants to two groups according to their history of tea drinking frequency and investigated both functional and structural networks to reveal the role of tea drinking on brain organization. The results showed that tea drinking gave rise to the more efficient structural organization, but had no significant beneficial effect on the global functional organization. The suppression of hemispheric asymmetry in the structural connectivity network was observed as a result of tea drinking. We did not observe any significant effects of tea drinking on the hemispheric asymmetry of the functional connectivity network. In addition, functional connectivity strength within the default mode network (DMN) was greater for the tea-drinking group, and coexistence of increasing and decreasing connective strengths was observed in the structural connectivity of the DMN. Our study offers the first evidence of the positive contribution of tea drinking to brain structure and suggests a protective effect on age-related decline in brain organisation.
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Affiliation(s)
- Junhua Li
- Laboratory for Brain-Bionic Intelligence and Computational Neuroscience, Wuyi University, Jiangmen, China
- Centre for Life Sciences, National University of Singapore, Singapore
- School of Computer Science and Electronic Engineering, University of Essex, Colchester, United Kingdom
| | - Rafael Romero-Garcia
- Brain Mapping Unit, Department of Psychiatry, University of Cambridge, Herchel Smith for Brain and Mind Sciences, Cambridge, United Kingdom
| | - John Suckling
- Brain Mapping Unit, Department of Psychiatry, University of Cambridge, Herchel Smith for Brain and Mind Sciences, Cambridge, United Kingdom
| | - Lei Feng
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Schuster J, Mitchell ES. More than just caffeine: psychopharmacology of methylxanthine interactions with plant-derived phytochemicals. Prog Neuropsychopharmacol Biol Psychiatry 2019; 89:263-274. [PMID: 30213684 DOI: 10.1016/j.pnpbp.2018.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 09/06/2018] [Accepted: 09/09/2018] [Indexed: 01/23/2023]
Abstract
In general, preparations of coffee, teas, and cocoa containing high levels of polyphenols, L-theanine and other bioactive compounds selectively enhance mood and cognition effects of caffeine. This review summarizes the bioactive components of commonly consumed natural caffeine sources (e.g. guayusa, mate and camellia teas, coffee and cocoa) and analyzes the psychopharmacology of constituent phytochemicals: methylxanthines, polyphenols, and L-theanine. Acute and chronic synergistic effects of these compounds on mood and cognition are compared and discussed. Specific sets of constituent compounds such as polyphenols, theobromine and L-theanine appear to enhance mood and cognition effects of caffeine and alleviate negative psychophysiological effects of caffeine. However, more research is needed to identify optimal combinations and ratios of caffeine and phytochemicals for enhancement of cognitive performance.
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Affiliation(s)
- Julius Schuster
- Swammerdam Institute for Life Sciences, Amsterdam, the Netherlands.
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Daou M, Sassi JM, Miller MW, Gonzalez AM. Effects of a Multi-Ingredient Energy Supplement on Cognitive Performance and Cerebral-Cortical Activation. J Diet Suppl 2019. [DOI: 10.1080/19390211.2018.1440686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Marcos Daou
- School of Kinesiology, Auburn University, Auburn, AL, USA
| | | | | | - Adam M. Gonzalez
- Department of Health Professions, Hofstra University, Hempstead, NY, USA
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Williams J, Sergi D, McKune AJ, Georgousopoulou EN, Mellor DD, Naumovski N. The beneficial health effects of green tea amino acid l
-theanine in animal models: Promises and prospects for human trials. Phytother Res 2019; 33:571-583. [DOI: 10.1002/ptr.6277] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 11/29/2018] [Accepted: 12/10/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Jackson Williams
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
| | - Domenico Sergi
- Commonwealth Scientific and Industrial Research Organisation (CSIRO)-Health and Biosecurity; Adelaide SA Australia
| | - Andrew J. McKune
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
- University of Canberra Research Institute for Sport and Exercise (UCRISE); Bruce ACT Australia
- Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences; University of KwaZulu-Natal; Durban South Africa
| | - Ekavi N. Georgousopoulou
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
- Department of Nutrition and Dietetics, School of Health Science and Education; Harokopio University; Athens Greece
| | - Duane D. Mellor
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
| | - Nenad Naumovski
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
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Newson JJ, Thiagarajan TC. EEG Frequency Bands in Psychiatric Disorders: A Review of Resting State Studies. Front Hum Neurosci 2019; 12:521. [PMID: 30687041 PMCID: PMC6333694 DOI: 10.3389/fnhum.2018.00521] [Citation(s) in RCA: 319] [Impact Index Per Article: 63.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/11/2018] [Indexed: 12/19/2022] Open
Abstract
A significant proportion of the electroencephalography (EEG) literature focuses on differences in historically pre-defined frequency bands in the power spectrum that are typically referred to as alpha, beta, gamma, theta and delta waves. Here, we review 184 EEG studies that report differences in frequency bands in the resting state condition (eyes open and closed) across a spectrum of psychiatric disorders including depression, attention deficit-hyperactivity disorder (ADHD), autism, addiction, bipolar disorder, anxiety, panic disorder, post-traumatic stress disorder (PTSD), obsessive compulsive disorder (OCD) and schizophrenia to determine patterns across disorders. Aggregating across all reported results we demonstrate that characteristic patterns of power change within specific frequency bands are not necessarily unique to any one disorder but show substantial overlap across disorders as well as variability within disorders. In particular, we show that the most dominant pattern of change, across several disorder types including ADHD, schizophrenia and OCD, is power increases across lower frequencies (delta and theta) and decreases across higher frequencies (alpha, beta and gamma). However, a considerable number of disorders, such as PTSD, addiction and autism show no dominant trend for spectral change in any direction. We report consistency and validation scores across the disorders and conditions showing that the dominant result across all disorders is typically only 2.2 times as likely to occur in the literature as alternate results, and typically with less than 250 study participants when summed across all studies reporting this result. Furthermore, the magnitudes of the results were infrequently reported and were typically small at between 20% and 30% and correlated weakly with symptom severity scores. Finally, we discuss the many methodological challenges and limitations relating to such frequency band analysis across the literature. These results caution any interpretation of results from studies that consider only one disorder in isolation, and for the overall potential of this approach for delivering valuable insights in the field of mental health.
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Bakoyiannis I, Daskalopoulou A, Pergialiotis V, Perrea D. Phytochemicals and cognitive health: Are flavonoids doing the trick? Biomed Pharmacother 2018; 109:1488-1497. [PMID: 30551400 DOI: 10.1016/j.biopha.2018.10.086] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 10/13/2018] [Accepted: 10/14/2018] [Indexed: 12/27/2022] Open
Abstract
Flavonoids constitute a large group of polyphenolic compounds with numerous effects on behaviour and cognition. These effects vary from learning and memory enhancement to an improvement of general cognition. Furthermore, flavonoids have been implicated in a) neuronal proliferation and survival, by acting on a variety of cellular signalling cascades, including the ERK/CREB/BDNF and PI3K/Akt pathway, b) oxidative stress reduction and c) relief from Alzheimer's disease-type symptoms. From an electrophysiological aspect, they promote long term potentiation in the hippocampus, supporting the hypothesis of synaptic plasticity mediation. Together, these actions reveal a neuroprotective effect of flavonoid compounds in the brain. Therefore, flavonoid intake could be a potential clinical direction for prevention and/or attenuation of cognitive decline deterioration which accompanies various brain disorders. The purpose of the current review paper was to summarise all these effects on cognition, describe the possible pathways via which they may act on a cellular level and provide a better picture for future research towards this direction.
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Affiliation(s)
- Ioannis Bakoyiannis
- Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, National and Kapodistrian University of Athens, Medical School, Greece.
| | - Afrodite Daskalopoulou
- Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, National and Kapodistrian University of Athens, Medical School, Greece
| | - Vasilios Pergialiotis
- Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, National and Kapodistrian University of Athens, Medical School, Greece
| | - Despina Perrea
- Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, National and Kapodistrian University of Athens, Medical School, Greece
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Dietz C, Dekker M. Effect of Green Tea Phytochemicals on Mood and Cognition. Curr Pharm Des 2018; 23:2876-2905. [PMID: 28056735 DOI: 10.2174/1381612823666170105151800] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/01/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Green tea is traditionally known to induce mental clarity, cognitive function, physical activation and relaxation. Recently, a special green tea, matcha tea, is rapidly gaining popularity throughout the world and is frequently referred to as a mood- and brain food. Matcha tea consumption leads to much higher intake of green tea phytochemicals compared to regular green tea. Previous research on tea constituents caffeine, L-theanine, and epigallocatechin gallate (EGCG) repeatedly demonstrated benefits on mood and cognitive performance. These effects were observed when these phytochemicals were consumed separately and in combination. METHODS A review was conducted on 49 human intervention studies to summarize the research on acute psychoactive effects of caffeine, L-theanine, and EGCG on different dimensions of mood and cognitive performance. CONCLUSION Caffeine was found to mainly improve performance on demanding long-duration cognitive tasks and self-reported alertness, arousal, and vigor. Significant effects already occurred at low doses of 40 mg. L-theanine alone improved self-reported relaxation, tension, and calmness starting at 200 mg. L-theanine and caffeine combined were found to particularly improve performance in attention-switching tasks and alertness, but to a lesser extent than caffeine alone. No conclusive evidence relating to effects induced by EGCG could be given since the amount of intervention studies was limited. These studies provided reliable evidence showing that L-theanine and caffeine have clear beneficial effects on sustained attention, memory, and suppression of distraction. Moreover, L-theanine was found to lead to relaxation by reducing caffeine induced arousal.
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Affiliation(s)
- Christina Dietz
- Food Quality and Design Group, Wageningen University, Wageningen, Netherlands
| | - Matthijs Dekker
- Food Quality and Design Group, Wageningen University, Wageningen, Netherlands
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21
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Turck D, Bresson J, Burlingame B, Dean T, Fairweather‐Tait S, Heinonen M, Hirsch‐Ernst KI, Mangelsdorf I, McArdle HJ, Naska A, Neuhäuser‐Berthold M, Nowicka G, Pentieva K, Sanz Y, Sjödin A, Stern M, Tomé D, Van Loveren H, Vinceti M, Willatts P, Martin A, Strain S(JJ, Siani A. Black tea and improvement of attention: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006. EFSA J 2018; 16:e05266. [PMID: 32625903 PMCID: PMC7009616 DOI: 10.2903/j.efsa.2018.5266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Following an application from Unilever NV, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Ireland, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to black tea and improvement of attention. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The food proposed by the applicant as the subject of the health claim is black tea. The Panel considers that black tea characterised by its content of tea solids, caffeine and l‐theanine, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect. The claimed effect proposed by the applicant is ‘improves attention’. The Panel considers that improvement of attention is a beneficial physiological effect. Three human intervention studies provided by the applicant show an effect of black tea on attention under the conditions of used proposed by the applicant. The applicant proposed that the claimed effect depends on the concerted action of two substances, caffeine and l‐theanine, both of which are present in black tea. The Panel considers that the effect of black tea on attention observed in the three human intervention studies provided by the applicant can be explained by its caffeine content. The Panel concludes that a cause and effect relationship has been established between the consumption of black tea and improvement of attention. The Panel considers that the effect of black tea on attention can be explained by its caffeine content. The following wording reflects the scientific evidence: ‘Owing to its caffeine content, black tea improves attention’. In order to obtain the claimed effect, 2–3 servings of black tea providing at least 75 mg of caffeine in total should be consumed within 90 min.
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Fernando WMADB, Somaratne G, Goozee KG, Williams S, Singh H, Martins RN. Diabetes and Alzheimer's Disease: Can Tea Phytochemicals Play a Role in Prevention? J Alzheimers Dis 2018; 59:481-501. [PMID: 28582855 DOI: 10.3233/jad-161200] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Dementia and diabetes mellitus are prevalent disorders in the elderly population. While recognized as two distinct diseases, diabetes has more recently recognized as a significant contributor to risk for developing dementia, and some studies make reference to type 3 diabetes, a condition resulting from insulin resistance in the brain. Alzheimer's disease, the most common form of dementia, and diabetes, interestingly, share underlying pathological processes, commonality in risk factors, and, importantly, pathways for intervention. Tea has been suggested to possess potent antioxidant properties. It is rich in phytochemicals including, flavonoids, tannins, caffeine, polyphenols, boheic acid, theophylline, theobromine, anthocyanins, gallic acid, and finally epigallocatechin-3-gallate, which is considered to be the most potent active ingredient. Flavonoid phytochemicals, known as catechins, within tea offer potential benefits for reducing the risk of diabetes and Alzheimer's disease by targeting common risk factors, including obesity, hyperlipidemia, hypertension, cardiovascular disease, and stroke. Studies also show that catechins may prevent the formation of amyloid-β plaques and enhance cognitive functions, and thus may be useful in treating patients who have Alzheimer's disease or dementia. Furthermore, other phytochemicals found within tea offer important antioxidant properties along with innate properties capable of modulating intracellular neuronal signal transduction pathways and mitochondrial function.
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Affiliation(s)
- Warnakulasuriya M A D B Fernando
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical Sciences, Edith Cowan University, Joondalup, Australia
| | - Geeshani Somaratne
- Massey Institute of Food Science and Technology, Massey University, Palmerston North, New Zealand.,Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Kathryn G Goozee
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical Sciences, Edith Cowan University, Joondalup, Australia.,School of Biomedical Science, Macquarie University, Sydney, NSW, Australia.,KARVIAH Research Centre, Anglicare, Castle Hill, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Nedlands, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
| | - Shehan Williams
- Faculty of Medicine, University of Kelaniya, Colombo, Sri Lanka
| | - Harjinder Singh
- Massey Institute of Food Science and Technology, Massey University, Palmerston North, New Zealand.,Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Ralph N Martins
- Centre of Excellence in Alzheimer's Disease Research and Care, School of Medical Sciences, Edith Cowan University, Joondalup, Australia.,School of Biomedical Science, Macquarie University, Sydney, NSW, Australia.,KARVIAH Research Centre, Anglicare, Castle Hill, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, The University of Western Australia, Nedlands, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
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Rizwan A, Zinchenko A, Özdem C, Rana MS, Al-Amin MM. The effect of black tea on human cognitive performance in a cognitive test battery. CLINICAL PHYTOSCIENCE 2017. [DOI: 10.1186/s40816-017-0049-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Kahathuduwa CN, Dhanasekara CS, Chin SH, Davis T, Weerasinghe VS, Dassanayake TL, Binks M. l-Theanine and caffeine improve target-specific attention to visual stimuli by decreasing mind wandering: a human functional magnetic resonance imaging study. Nutr Res 2017; 49:67-78. [PMID: 29420994 DOI: 10.1016/j.nutres.2017.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 10/31/2017] [Accepted: 11/12/2017] [Indexed: 11/17/2022]
Abstract
Oral intake of l-theanine and caffeine supplements is known to be associated with faster stimulus discrimination, possibly via improving attention to stimuli. We hypothesized that l-theanine and caffeine may be bringing about this beneficial effect by increasing attention-related neural resource allocation to target stimuli and decreasing deviation of neural resources to distractors. We used functional magnetic resonance imaging (fMRI) to test this hypothesis. Solutions of 200mg of l-theanine, 160mg of caffeine, their combination, or the vehicle (distilled water; placebo) were administered in a randomized 4-way crossover design to 9 healthy adult men. Sixty minutes after administration, a 20-minute fMRI scan was performed while the subjects performed a visual color stimulus discrimination task. l-Theanine and l-theanine-caffeine combination resulted in faster responses to targets compared with placebo (∆=27.8milliseconds, P=.018 and ∆=26.7milliseconds, P=.037, respectively). l-Theanine was associated with decreased fMRI responses to distractor stimuli in brain regions that regulate visual attention, suggesting that l-theanine may be decreasing neural resource allocation to process distractors, thus allowing to attend to targets more efficiently. l-Theanine-caffeine combination was associated with decreased fMRI responses to target stimuli as compared with distractors in several brain regions that typically show increased activation during mind wandering. Factorial analysis suggested that l-theanine and caffeine seem to have a synergistic action in decreasing mind wandering. Therefore, our hypothesis is that l-theanine and caffeine may be decreasing deviation of attention to distractors (including mind wandering); thus, enhancing attention to target stimuli was confirmed.
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Affiliation(s)
- Chanaka N Kahathuduwa
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA; Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka; Department of Human Development and Family Studies, Texas Tech University, Lubbock, TX, USA
| | - Chathurika S Dhanasekara
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Shao-Hua Chin
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Tyler Davis
- Department of Human Development and Family Studies, Texas Tech University, Lubbock, TX, USA; Department of Psychological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Vajira S Weerasinghe
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka
| | - Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka; School of Psychology, The University of Newcastle, New South Wales, Australia
| | - Martin Binks
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.
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Saeed M, Naveed M, Arif M, Kakar MU, Manzoor R, Abd El-Hack ME, Alagawany M, Tiwari R, Khandia R, Munjal A, Karthik K, Dhama K, Iqbal HMN, Dadar M, Sun C. Green tea (Camellia sinensis) and l-theanine: Medicinal values and beneficial applications in humans-A comprehensive review. Biomed Pharmacother 2017; 95:1260-1275. [PMID: 28938517 DOI: 10.1016/j.biopha.2017.09.024] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 09/03/2017] [Accepted: 09/06/2017] [Indexed: 02/05/2023] Open
Abstract
Green tea (Camellia sinensis) is a famous herb, and its extract has been extensively used in traditional Chinese medicinal system. In this context, several studies have revealed its health benefits and medicinal potentialities for several ailments. With ever increasing scientific knowledge, search for safer, potential and novel type of health-related supplements quest, scientists are re-directing their research interests to explore natural resources i.e. medicinal herbs/plant derived compounds. Green tea consumption has gained a special attention and popularity in the modern era of changing lifestyle. The present review is aimed to extend the current knowledge by highlighting the importance and beneficial applications of green tea in humans for safeguarding various health issues. Herein, we have extensively reviewed, analyzed, and compiled salient information on green tea from the authentic published literature available in PubMed and other scientific databases. Scientific literature evidenced that owing to the bioactive constituents including caffeine, l-theanine, polyphenols/flavonoids and other potent molecules, green tea has many pharmacological and physiological functions. It possesses multi-beneficial applications in treating various disorders of humans. This review also provides in-depth insights on the medicinal values of green tea which will be useful for researchers, medical professionals, veterinarians, nutritionists, pharmacists and pharmaceutical industry. Future research emphasis and promotional avenues are needed to explore its potential therapeutic applications for designing appropriate pharmaceuticals, complementary medicines, and effective drugs as well as popularize and propagate its multidimensional health benefits.
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Affiliation(s)
- Muhammad Saeed
- College of Animal Science and Technology, NW A&F University, Yangling, Shaanxi, 712100, China; Institute of Animal Sciences, Faculty of Animal Husbandry, University of Agriculture, Faisalabad, 38040, Pakistan
| | - Muhammad Naveed
- Department of Clinical Pharmacy, School of Basic Medicine, and Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu Province, 211198, China; Department of Urology Surgery, Aviation General Hospital, Beijing, 100012, China
| | - Muhammad Arif
- Department of Animal Sciences, University College of Agriculture, University of Sargodha, 40100, Pakistan
| | - Mohib Ullah Kakar
- Faculty of Marine Sciences, Lasbela University of Agriculture, Water and Marine Sciences, Uthal, Balochistan, 3800, Pakistan
| | - Robina Manzoor
- Faculty of Marine Sciences, Lasbela University of Agriculture, Water and Marine Sciences, Uthal, Balochistan, 3800, Pakistan
| | | | - Mahmoud Alagawany
- Poultry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt.
| | - Ruchi Tiwari
- Department of Veterinary Microbiology and Immunology, College of Veterinary Sciences, UP Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan (DUVASU), Mathura, Uttar Pradesh, 281 001, India
| | - Rekha Khandia
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, 462 026 M.P., India
| | - Ashok Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, 462 026 M.P., India
| | - Kumaragurubaran Karthik
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, Tamil Nadu, 600051, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, 243 122, Uttar Pradesh, India
| | - Hafiz M N Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, Monterrey, N.L., CP 64849, Mexico
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Chao Sun
- College of Animal Science and Technology, NW A&F University, Yangling, Shaanxi, 712100, China.
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Mancini E, Beglinger C, Drewe J, Zanchi D, Lang UE, Borgwardt S. Green tea effects on cognition, mood and human brain function: A systematic review. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2017; 34:26-37. [PMID: 28899506 DOI: 10.1016/j.phymed.2017.07.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/19/2016] [Accepted: 07/21/2017] [Indexed: 05/23/2023]
Abstract
BACKGROUND Green tea (Camellia sinensis) is a beverage consumed for thousands of years. Numerous claims about the benefits of its consumption were stated and investigated. As green tea is experiencing a surge in popularity in Western culture and as millions of people all over the world drink it every day, it is relevant to understand its effects on the human brain. PURPOSE To assess the current state of knowledge in the literature regarding the effects of green tea or green tea extracts, l-theanine and epigallocatechin gallate both components of green tea-on general neuropsychology, on the sub-category cognition and on brain functions in humans. METHODS We systematically searched on PubMed database and selected studies by predefined eligibility criteria. We then assessed their quality and extracted data. We structured our effort according to the PRISMA statement. OUTCOME We reviewed and assessed 21 studies, 4 of which were randomised controlled trials, 12 cross-over studies (both assessed with an adapted version of the DELPHI-list), 4 were cross-sectional studies and one was a cohort study (both assessed with an adapted version of the Newcastle-Ottawa assessment scale). The average study quality as appraised by means of the DELPHI-list was good (8.06/9); the studies evaluated with the Newcastle-Ottawa-scale were also good (6.7/9). CONCLUSIONS The reviewed studies presented evidence that green tea influences psychopathological symptoms (e.g. reduction of anxiety), cognition (e.g. benefits in memory and attention) and brain function (e.g. activation of working memory seen in functional MRI). The effects of green tea cannot be attributed to a single constituent of the beverage. This is exemplified in the finding that beneficial green tea effects on cognition are observed under the combined influence of both caffeine and l-theanine, whereas separate administration of either substance was found to have a lesser impact.
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Affiliation(s)
- Edele Mancini
- University of Basel, Department of Psychiatry, Wilhelm Klein Str. 27, 4012 Basel, Switzerland
| | - Christoph Beglinger
- University Hospital Basel, Department of Gastroenterology, 4031 Basel, Switzerland
| | - Jürgen Drewe
- University Hospital Basel, Department of Gastroenterology, 4031 Basel, Switzerland
| | - Davide Zanchi
- University of Basel, Department of Psychiatry, Wilhelm Klein Str. 27, 4012 Basel, Switzerland
| | - Undine E Lang
- University of Basel, Department of Psychiatry, Wilhelm Klein Str. 27, 4012 Basel, Switzerland
| | - Stefan Borgwardt
- University of Basel, Department of Psychiatry, Wilhelm Klein Str. 27, 4012 Basel, Switzerland; King's College London, Institute of Psychiatry, Department of Psychosis Studies, London, United Kingdom.
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Hasani P, Tehrani HS, Yaghmaei P, Roudbari NH. Effects of Camellia Sinensis Extract on Passive Avoidance Learning and Hippocampal Neurogenesis in Rats. NEUROPHYSIOLOGY+ 2017. [DOI: 10.1007/s11062-017-9642-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Wilson TJ, Gray MJ, Van Klinken JW, Kaczmarczyk M, Foxe JJ. Macronutrient composition of a morning meal and the maintenance of attention throughout the morning. Nutr Neurosci 2017; 21:729-743. [PMID: 28714768 PMCID: PMC5924415 DOI: 10.1080/1028415x.2017.1347998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND At present, the impact of macronutrient composition and nutrient intake on sustained attention in adults is unclear, although some prior work suggests that nutritive interventions that engender slow, steady glucose availability support sustained attention after consumption. A separate line of evidence suggests that nutrient consumption may alter electroencephalographic markers of neurophysiological activity, including neural oscillations in the alpha-band (8-14 Hz), which are known to be richly interconnected with the allocation of attention. It is here investigated whether morning ingestion of foodstuffs with differing macronutrient compositions might differentially impact the allocation of sustained attention throughout the day as indexed by both behavior and the deployment of attention-related alpha-band activity. METHODS Twenty-four adult participants were recruited into a three-day study with a cross-over design that employed a previously validated sustained attention task (the Spatial CTET). On each experimental day, subjects consumed one of three breakfasts with differing carbohydrate availabilities (oatmeal, cornflakes, and water) and completed blocks of the Spatial CTET throughout the morning while behavioral performance, subjective metrics of hunger/fullness, and electroencephalographic (EEG) measurements of alpha oscillatory activity were recorded. RESULTS Although behavior and electrophysiological metrics changed over the course of the day, no differences in their trajectories were observed as a function of breakfast condition. However, subjective metrics of hunger/fullness revealed that caloric interventions (oatmeal and cornflakes) reduced hunger across the experimental day with respect to the non-caloric, volume-matched control (water). Yet, no differences in hunger/fullness were observed between the oatmeal and cornflakes interventions. CONCLUSION Observation of a relationship between macronutrient intervention and sustained attention (if one exists) will require further standardization of empirical investigations to aid in the synthesis and replicability of results. In addition, continued implementation of neurophysiological markers in this domain is encouraged, as they often produce nuanced insight into cognition even in the absence of overt behavioral changes. ClinicalTrials.gov Identifier: NCT03169283.
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Affiliation(s)
- Tommy J Wilson
- a The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics , Albert Einstein College of Medicine & Montefiore Medical Center , Bronx , NY 10461 , USA.,b The Dominick P. Purpura Department of Neuroscience , Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Rose F. Kennedy Center , Bronx , NY 10461 , USA
| | - Michael J Gray
- d The Graduate Center of the City University of New York , New York , NY 10031
| | | | | | - John J Foxe
- a The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics , Albert Einstein College of Medicine & Montefiore Medical Center , Bronx , NY 10461 , USA.,c Department of Neuroscience , The Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry , Rochester , NY 14642 , USA
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Dietz C, Dekker M, Piqueras-Fiszman B. An intervention study on the effect of matcha tea, in drink and snack bar formats, on mood and cognitive performance. Food Res Int 2017; 99:72-83. [PMID: 28784536 DOI: 10.1016/j.foodres.2017.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/16/2017] [Accepted: 05/04/2017] [Indexed: 12/16/2022]
Abstract
Matcha tea is gaining popularity throughout the world in recent years and is frequently referred to as a mood-and-brain food. Previous research has demonstrated that three constituents present in matcha tea, l-theanine, epigallocatechin gallate (EGCG), and caffeine, affect mood and cognitive performance. However, to date there are no studies assessing the effect of matcha tea itself. The present study investigates these effects by means of a human intervention study administering matcha tea and a matcha containing product. Using a randomized, placebo-controlled, single-blind study, 23 consumers participated in four test sessions. In each session, participants consumed one of the four test products: matcha tea, matcha tea bar (each containing 4g matcha tea powder), placebo tea, or placebo bar. The assessment was performed at baseline and 60min post-treatment. The participants performed a set of cognitive tests assessing attention, information processing, working memory, and episodic memory. The mood state was measured by means of a Profile of Mood States (POMS). After consuming the matcha products compared to placebo versions, there were mainly significant improvements in tasks measuring basic attention abilities and psychomotor speed in response to stimuli over a defined period of time. In contrast to expectations, the effect was barely present in the other cognitive tasks. The POMS results revealed no significant changes in mood. The influence of the food matrix was demonstrated by the fact that on most cognitive performance measures the drink format outperformed the bar format, particularly in tasks measuring speed of spatial working memory and delayed picture recognition. This study suggests that matcha tea consumed in a realistic dose can induce slight effects on speed of attention and episodic secondary memory to a low degree. Further studies are required to elucidate the influences of the food matrix.
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Affiliation(s)
- Christina Dietz
- Food Quality and Design Group, Wageningen University, The Netherlands
| | - Matthijs Dekker
- Food Quality and Design Group, Wageningen University, The Netherlands
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Wilhelmus MM, Hay JL, Zuiker RG, Okkerse P, Perdrieu C, Sauser J, Beaumont M, Schmitt J, van Gerven JM, Silber BY. Effects of a single, oral 60 mg caffeine dose on attention in healthy adult subjects. J Psychopharmacol 2017; 31:222-232. [PMID: 27649778 DOI: 10.1177/0269881116668593] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Caffeine induces positive effects on sustained attention, although studies assessing the acute effects of low caffeine dose (<75 mg) on sustained attention are limited and use short-term tests. Therefore, we investigated the acute effects of a 60 mg dose of caffeine on sustained attention in tests lasting up to 45 minutes using 82 low or non-caffeine-consuming healthy male ( n=41) and female ( n=41) adults aged between 40 and 60 years. Vigilance was measured using Mackworth Clock test, Rapid Visual Information Processing Test, adaptive tracking test, saccadic eye movement and attention switch test. Effects on mood and fatigue were analysed using Bond and Lader and Caffeine Research visual analogue scales, and Samn-Perelli questionnaire. Saliva sampling was performed for both compliance and caffeine pharmacokinetic analysis. Administration of a 60 mg caffeine dose resulted in a significant improvement in sustained attention compared with the placebo. Also a significantly improved peak saccadic velocity and reaction time performance was found, and decreased error rate. Significantly increased feelings of alertness, contentment and overall mood after caffeine treatment compared with placebo were observed. This study demonstrated that in healthy adult subjects oral administration of a single 60 mg caffeine dose elicited a clear enhancement of sustained attention and alertness, measured both in multiple objective performances and in subjective scales.
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Affiliation(s)
- Micha Mm Wilhelmus
- 1 Centre for Human Drug Research (CHDR), Leiden, the Netherlands.,3 Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, the Netherlands
| | - Justin L Hay
- 1 Centre for Human Drug Research (CHDR), Leiden, the Netherlands
| | - Rob Gja Zuiker
- 1 Centre for Human Drug Research (CHDR), Leiden, the Netherlands
| | - Pieter Okkerse
- 1 Centre for Human Drug Research (CHDR), Leiden, the Netherlands
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Giles GE, Mahoney CR, Brunyé TT, Taylor HA, Kanarek RB. Caffeine and theanine exert opposite effects on attention under emotional arousal. Can J Physiol Pharmacol 2017; 95:93-100. [DOI: 10.1139/cjpp-2016-0498] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Tea is perceived as more relaxing than coffee, even though both contain caffeine. L-theanine in tea may account for the difference. Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitigates physiological and felt stress responses. We evaluated whether caffeine and theanine influenced cognition under emotional arousal. Using a double-blind, repeated-measures design, 36 participants received 4 treatments (200 mg caffeine + 0 mg theanine, 0 mg caffeine + 200 mg theanine, 200 mg caffeine + 200 mg theanine, 0 mg caffeine + 0 mg theanine) on separate days. Emotional arousal was induced by highly arousing negative film clips and pictures. Mood, salivary cortisol, and visual attention were evaluated. Caffeine accentuated global processing of visual attention on the hierarchical shape task (p < 0.05), theanine accentuated local processing (p < 0.05), and the combination did not differ from placebo. Caffeine reduced flanker conflict difference scores on the Attention Network Test (p < 0.05), theanine increased difference scores (p < 0.05), and the combination did not differ from placebo. Thus, under emotional arousal, caffeine and theanine exert opposite effects on certain attentional processes, but when consumed together, they counteract the effects of each other.
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Affiliation(s)
- Grace E. Giles
- Department of Psychology, Tufts University, Medford, MA 02155, USA
- Department of Psychology, Tufts University, Medford, MA 02155, USA
| | - Caroline R. Mahoney
- Department of Psychology, Tufts University, Medford, MA 02155, USA
- Department of Psychology, Tufts University, Medford, MA 02155, USA
| | - Tad T. Brunyé
- Department of Psychology, Tufts University, Medford, MA 02155, USA
- Department of Psychology, Tufts University, Medford, MA 02155, USA
| | - Holly A. Taylor
- Department of Psychology, Tufts University, Medford, MA 02155, USA
- Department of Psychology, Tufts University, Medford, MA 02155, USA
| | - Robin B. Kanarek
- Department of Psychology, Tufts University, Medford, MA 02155, USA
- Department of Psychology, Tufts University, Medford, MA 02155, USA
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l-Theanine as a Functional Food Additive: Its Role in Disease Prevention and Health Promotion. BEVERAGES 2016. [DOI: 10.3390/beverages2020013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Boros K, Jedlinszki N, Csupor D. Theanine and Caffeine Content of Infusions Prepared from Commercial Tea Samples. Pharmacogn Mag 2016; 12:75-9. [PMID: 27019564 PMCID: PMC4787341 DOI: 10.4103/0973-1296.176061] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Background: Caffeine and L-theanine are pharmacologically important constituents of tea, especially due to their effects on the central nervous system. The effects of these two compounds are opposite: While caffeine is a well-known stimulant, theanine has a relaxing effect. Tea processing may influence the caffeine and theanine content of tea leaves. Objective: The aim of our work was to quantify these constituents from a set of commercial products to reveal the possible correlations of caffeine and theanine content and processing methods. Materials and Methods: Theanine and caffeine contents of 37 commercial white, green, oolong, black, and pu-erh tea samples were quantified by high-performance liquid chromatography-diode array detector. Results: The mean L-theanine content of white, green, oolong, and black teas were 6.26, 6.56, 6.09, and 5.13 mg/g, respectively. The same values for caffeine content were 16.79, 16.28, 19.31, and 17.73 mg/g. Conclusion: Though the effect of processing on theanine content was evident, quantification for these analytes does not seem to be a good criterion to discriminate the different types of tea. Caffeine content provided no information on the effect of processing, and the theanine content of the samples was rather variable, independently from the type of the tea. The quantitative analysis of caffeine and theanine is essential to assess the stimulating effect of the tea, however, for chemical profiling further secondary metabolites have to be determined. SUMMARY Thirty-seven commercial white, green, oolong, black, and pu-erh tea samples were analyzed for caffeine and theanine content While the caffeine content was similar, the theanine contents of black teas were slightly lower and practically zero in pu-erh The great variability of these two compound within the tea categories allows no discrimination of tea types based solely on theanine and caffeine quantification Contrary to the previous data, the way of processing has no determining effect on theanine content.
Abbreviations used: CZE: Capillary zone electrophoresis, DAD: Diode array detector, EEG: Electroencephalography, GC: Gas chromatography, HPLC: High-performance liquid chromatography, IR: Infrared spectroscopy, MEKC: Micellar electrokinetic capillary chromatography, MS: Mass spectrometry, RP: Reversed phase, RSD: Relative standard deviation, SD: Standard deviation, TLC: Tile liquid chromatography, UV: Ultraviolet
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Affiliation(s)
- Klára Boros
- Department of Pharmacognosy, Faculty of Pharmacy, University of Szeged, H-6720 Szeged, Hungary
| | - Nikoletta Jedlinszki
- Department of Pharmacognosy, Faculty of Pharmacy, University of Szeged, H-6720 Szeged, Hungary
| | - Dezső Csupor
- Department of Pharmacognosy, Faculty of Pharmacy, University of Szeged, H-6720 Szeged, Hungary
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Kahathuduwa CN, Dassanayake TL, Amarakoon AMT, Weerasinghe VS. Acute effects of theanine, caffeine and theanine–caffeine combination on attention. Nutr Neurosci 2016; 20:369-377. [DOI: 10.1080/1028415x.2016.1144845] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Chanaka N. Kahathuduwa
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka
- Department of Nutritional Sciences, Texas Tech University, Lubbock, USA
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Türközü D, Şanlier N. L-theanine, unique amino acid of tea, and its metabolism, health effects, and safety. Crit Rev Food Sci Nutr 2015; 57:1681-1687. [DOI: 10.1080/10408398.2015.1016141] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Childs E. Influence of energy drink ingredients on mood and cognitive performance. Nutr Rev 2015; 72 Suppl 1:48-59. [PMID: 25293543 DOI: 10.1111/nure.12148] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sales of energy products have grown enormously in recent years. Manufacturers claim that the products, in the form of drinks, shots, supplements, and gels, enhance physical and cognitive performance, while users believe the products promote concentration, alertness, and fun. Most of these products contain caffeine, a mild psychostimulant, as their foremost active ingredient. However, they also contain additional ingredients, e.g., carbohydrates, amino acids, herbal extracts, vitamins, and minerals, often in unspecified amounts and labeled as an "energy blend." It is not clear whether these additional ingredients provide any physical or cognitive enhancement beyond that provided by caffeine alone. This article reviews the available empirical data on the interactive effects of these ingredients and caffeine on sleep and cognitive performance and suggests objectives for future study.
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Affiliation(s)
- Emma Childs
- The University of Chicago, Department of Psychiatry and Behavioral Neuroscience, Chicago, Illinois, USA
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37
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Dodd FL, Kennedy DO, Riby LM, Haskell-Ramsay CF. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology (Berl) 2015; 232:2563-76. [PMID: 25761837 PMCID: PMC4480845 DOI: 10.1007/s00213-015-3895-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 02/11/2015] [Indexed: 01/09/2023]
Abstract
RATIONALE Evidence suggests interactive effects of the tea components caffeine and L-theanine on behaviour, yet no data exists exploring the impact of the two on cerebral blood flow (CBF). OBJECTIVES The current placebo-controlled, double-blind, counterbalanced, crossover study examined the effects of caffeine and L-theanine on CBF and extended previous cognitive and mood findings by using lower doses than previous studies of a similar methodology, which more closely reflect the ratios present in tea. METHODS Twelve habitual consumers and 12 non-habitual consumers of caffeine each received 75 mg caffeine, 50 mg L-theanine, 75 mg caffeine plus 50 mg L-theanine, and placebo in a counterbalanced order across four separate visits. CBF was measured via near-infrared spectroscopy with cognition and mood assessed at baseline and 30 min post-dose. Salivary caffeine and peripheral haemodynamics were co-monitored. RESULTS Caffeine reduced oxygenated haemoglobin (oxy-Hb), increased deoxygenated haemoglobin (deoxy-Hb), improved performance on attention tasks and increased overall mood ratings. Increases in deoxy-Hb following caffeine were more pronounced in non-consumers. Some evidence for increased deoxy-Hb remained when caffeine was combined with L-theanine, but this effect was attenuated and the effects of caffeine on oxy-Hb, cognition and mood were eradicated. CONCLUSIONS Combining L-theanine with caffeine, at levels and ratios equivalent to one to two cups of tea, eliminated the vasoconstrictive effect and behavioural effects of caffeine. This supports previous findings of an interaction between these substances, despite a lack of effects of L-theanine in isolation. However, at the levels tested here, this did not lead to a positive impact on behaviour.
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Affiliation(s)
- F. L. Dodd
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
| | - D. O. Kennedy
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
| | - L. M. Riby
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
| | - C. F. Haskell-Ramsay
- Brain, Performance and Nutrition Research Centre, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST UK
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38
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Baker LB, Nuccio RP, Jeukendrup AE. Acute effects of dietary constituents on motor skill and cognitive performance in athletes. Nutr Rev 2014; 72:790-802. [PMID: 25400063 DOI: 10.1111/nure.12157] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Performance in many sports is at least partially dependent on motor control, coordination, decision-making, and other cognitive tasks. This review summarizes available evidence about the ingestion of selected nutrients or isolated compounds (dietary constituents) and potential acute effects on motor skill and/or cognitive performance in athletes. Dietary constituents discussed include branched-chain amino acids, caffeine, carbohydrate, cocoa flavanols, Gingko biloba, ginseng, guarana, Rhodiola rosea, sage, L-theanine, theobromine, and tyrosine. Although this is not an exhaustive list, these are perhaps the most researched dietary constituents. Caffeine and carbohydrate have the greatest number of published reports supporting their ability to enhance acute motor skill and cognitive performance in athletes. At this time, there is insufficient published evidence to substantiate the use of any other dietary constituents to benefit sports-related motor skill or cognitive performance. The optimal dose and timing of caffeine and carbohydrate intake promoting enhanced motor skill and cognitive performance remain to be identified. Valid, reliable, and sensitive batteries of motor skills and cognitive tests should be developed for use in future efficacy studies.
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Affiliation(s)
- Lindsay B Baker
- Gatorade Sports Science Institute, Barrington, Illinois, USA
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Rana A, Singh HP, Gulati A. Concurrent Analysis of Theanine, Caffeine, and Catechins Using Hydrophobic Selective C12 Stationary Phase. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2014.962144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Ajay Rana
- Academy of Scientific and Innovative Research (AcSIR), Tea Technology Lab, Hill Area Tea Science Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Harsh Pratap Singh
- Academy of Scientific and Innovative Research (AcSIR), Tea Technology Lab, Hill Area Tea Science Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Ashu Gulati
- Academy of Scientific and Innovative Research (AcSIR), Tea Technology Lab, Hill Area Tea Science Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
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Häusser JA, Schlemmer A, Kaiser S, Kalis A, Mojzisch A. The effects of caffeine on option generation and subsequent choice. Psychopharmacology (Berl) 2014; 231:3719-27. [PMID: 24682504 DOI: 10.1007/s00213-014-3506-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 02/12/2014] [Indexed: 11/30/2022]
Abstract
RATIONALE Although the effects of caffeine on basic cognitive functions are well-known, its effects on more complex decision making, particularly on option generation, is yet to be explored. OBJECTIVE We examined the effects of caffeine on option generation in decision making using everyday life decisional situations. METHODS In a double-blind placebo-controlled experiment, participants (N = 47) either received 300 mg of caffeine or a placebo. Participants had to generate choice options (things they could do) for a series of high and low familiar real-world scenarios and, subsequently, to decide among these options. RESULTS Analyses revealed that participants in the caffeine condition generated significantly fewer options than participants in the placebo condition. Moreover, caffeine significantly reduced the option generation onset time, that is, participants in the caffeine condition generated their first option significantly faster than participants in the placebo condition. Regarding subsequent choice, we found evidence supporting the "take-the-first" heuristic, that is, the tendency to select the first generated option. This tendency was neither affected by caffeine nor by the familiarity of the scenarios. CONCLUSIONS Caffeine results in fewer options generated in unconstrained real-life decision-making situations and decreases generation onset times.
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Affiliation(s)
- Jan Alexander Häusser
- Institute of Psychology, University of Hildesheim, Marienburger Platz 22, 37141, Hildesheim, Germany,
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Camfield DA, Stough C, Farrimond J, Scholey AB. Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis. Nutr Rev 2014; 72:507-22. [PMID: 24946991 DOI: 10.1111/nure.12120] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
A systematic review and meta-analysis was conducted on 11 randomized placebo-controlled human studies of acute effects of tea constituents L-theanine and epigallocatechin gallate, administered alone or in combination with caffeine, on cognitive function and mood. The outcome measures of mood were alertness, calmness, and contentedness, derived from the Bond-Lader scales, and state anxiety, from the State-Trait Anxiety Inventory. Cognitive measures assessed were attentional switch, intersensory attention, and rapid visual information processing. Standardized mean differences between placebo and treatment groups are presented for each study and outcome measure. Meta-analysis using a random-effects model was conducted when data were available for three or more studies. Evidence of moderate effect sizes in favor of combined caffeine and L-theanine in the first 2 hours postdose were found for outcome measures Bond-Lader alertness, attentional switching accuracy, and, to a lesser extent, some unisensory and multisensory attentional outcomes. Moderator analysis of caffeine and L-theanine doses revealed trends toward greater change in effect size for caffeine dose than for L-theanine dose, particularly during the first hour postdose.
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Affiliation(s)
- David A Camfield
- Centre for Human Psychopharmacology, Swinburne University, Hawthorn, Australia
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Tamano H, Fukura K, Suzuki M, Sakamoto K, Yokogoshi H, Takeda A. Advantageous effect of theanine intake on cognition. Nutr Neurosci 2014; 17:279-83. [DOI: 10.1179/1476830513y.0000000094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Thangarajan S, Deivasigamani A, Natarajan SS, Krishnan P, Mohanan SK. Neuroprotective activity ofL-theanine on 3-nitropropionic acid-induced neurotoxicity in rat striatum. Int J Neurosci 2014; 124:673-84. [DOI: 10.3109/00207454.2013.872642] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Maeda-Yamamoto M, Okuda Y, Ohsuge T, Monobe M. Examination of Conditions for the Efficient Extraction of Various Functional Ingredients from Tea Leaves ( Camellia sinensis L.) using a Tea Infuser, ‘Rich plus’ (RICH+ ®). J JPN SOC FOOD SCI 2014. [DOI: 10.3136/nskkk.61.586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Einöther SJ, Martens VE. Acute effects of tea consumption on attention and mood. Am J Clin Nutr 2013; 98:1700S-1708S. [PMID: 24172303 DOI: 10.3945/ajcn.113.058248] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tea has historically been associated with mood and performance benefits, such as relaxation and concentration. This review summarizes the research on the acute effects of tea, and its ingredients theanine and caffeine, on attention and mood. Consistent with abundant research on the benefits of caffeine, the performance benefits of tea were identified in a number of studies, with particularly consistent evidence for improved attention. Tea consumption also consistently improved self-reported alertness and arousal, whereas effects on pleasure or relaxation were less consistent. In addition to the research on caffeine in real-life performance, 2 recent studies have provided a broader perspective on tea's effects on psychological function in that they showed beneficial effects in related areas such as work performance and creativity. These studies showed the validity of laboratory findings by supporting the idea that tea consumption has acute benefits on both mood and performance in real-life situations.
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Giesbrecht T, Rycroft J, Rowson M, De Bruin E. The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutr Neurosci 2013; 13:283-90. [DOI: 10.1179/147683010x12611460764840] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Abstract
Research into the cognitive and mood effects of caffeine in human subjects has highlighted some fairly robust and well-accepted effects. However, the majority of these studies have focused on caffeine in isolation; whilst caffeine is normally consumed in the form of plant-derived products and extracts that invariably contain other potentially bioactive phytochemicals. The aim of the present review is to consider the possible mechanisms of action of co-occurring phytochemicals, and any epidemiological evidence suggesting that they contribute to potential health benefits ascribed to caffeine. Intervention studies to date that have been conducted to explore the effects on brain function of the non-caffeine components in caffeine-bearing plants (coffee, tea, cocoa, guaraná), either alone or in combination with caffeine, will also be summarised. Research is beginning to accumulate showing independent effects for several of the phytochemicals that co-occur with caffeine, and/or a modulation of the effects of caffeine when it is co-consumed with these naturally concomitant phytochemicals. The present review highlights that more research aimed at understanding the effects of these compounds is needed and, more importantly, the synergistic relationship that they may have with caffeine.
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Tamano H, Fukura K, Suzuki M, Sakamoto K, Yokogoshi H, Takeda A. Preventive effect of theanine intake on stress-induced impairments of hippocamapal long-term potentiation and recognition memory. Brain Res Bull 2013; 95:1-6. [PMID: 23458739 DOI: 10.1016/j.brainresbull.2013.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 01/24/2013] [Accepted: 02/20/2013] [Indexed: 12/31/2022]
Abstract
Theanine, γ-glutamylethylamide, is one of the major amino acid components in green tea. On the basis of the preventive effect of theanine intake after birth on mild stress-induced attenuation of hippocamapal CA1 long-term potentiation (LTP), the present study evaluated the effect of theanine intake after weaning on stress-induced impairments of LTP and recognition memory. Young rats were fed water containing 0.3% theanine for 3 weeks after weaning and subjected to water immersion stress for 30min, which was more severe than tail suspension stress for 30s used previously. Serum corticosterone levels were lower in theanine-administered rats than in the control rats even after exposure to stress. CA1 LTP induced by a 100-Hz tetanus for 1s was inhibited in the presence of 2-amino-5-phosphonovalerate (APV), an N-methyl-d-aspartate (NMDA) receptor antagonist, in hippocampal slices from the control rats and was attenuated by water immersion stress. In contrast, CA1 LTP was not significantly inhibited in the presence of APV in hippocampal slices from theanine-administered rats and was not attenuated by the stress. Furthermore, object recognition memory was impaired in the control rats, but not in theanine-administered rats. The present study indicates the preventive effect of theanine intake after weaning on stress-induced impairments of hippocampal LTP and recognition memory. It is likely that the modification of corticosterone secretion after theanine intake is involved in the preventive effect.
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Affiliation(s)
- Haruna Tamano
- Graduate School of Pharmaceutical Sciences, University of Shizuoka, Global COE, Japan
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Caffeine as an attention enhancer: reviewing existing assumptions. Psychopharmacology (Berl) 2013; 225:251-74. [PMID: 23241646 DOI: 10.1007/s00213-012-2917-4] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
Abstract
RATIONALE Despite the large number of studies on the behavioural effects of caffeine, an unequivocal conclusion had not been reached. In this review, we seek to disentangle a number of questions. OBJECTIVE Whereas there is a general consensus that caffeine can improve performance on simple tasks, it is not clear whether complex tasks are also affected, or if caffeine affects performance of the three attention networks (alerting, orienting and executive control). Other questions being raised in this review are whether effects are more pronounced for higher levels of caffeine, are influenced by habitual caffeine use and whether there effects are due to withdrawal reversal. METHOD Literature review of double-blind placebo controlled studies that assessed acute effects of caffeine on attention tasks in healthy adult volunteers. RESULTS Caffeine improves performance on simple and complex attention tasks, and affects the alerting, and executive control networks. Furthermore, there is inconclusive evidence on dose-related performance effects of caffeine, or the influence of habitual caffeine consumption on the performance effects of caffeine. Finally, caffeine's effects cannot be attributed to withdrawal reversal. CONCLUSIONS Evidence shows that caffeine has clear beneficial effects on attention, and that the effects are even more widespread than previously assumed.
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Zhang X, Xu F, Gao Y, Wu J, Sun Y, Zeng X. Optimising the extraction of tea polyphenols, (−)-epigallocatechin gallate and theanine from summer green tea by using response surface methodology. Int J Food Sci Technol 2012. [DOI: 10.1111/j.1365-2621.2012.03082.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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