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L-theanine, a natural constituent in tea, and its effect on mental state

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Abstract

Tea is the most widely consumed beverage in the world after water. Tea is known to be a rich source of flavonoid antioxidants. However tea also contains a unique amino acid, L-theanine that may modulate aspects of brain function in humans. Evidence from human electroencephalograph (EEG) studies show that it has a direct effect on the brain (Juneja et al. Trends in Food Science & Tech 1999;10;199-204). L-theanine significantly increases activity in the alpha frequency band which indicates that it relaxes the mind without inducing drowsiness. However, this effect has only been established at higher doses than that typically found in a cup of black tea (approximately 20mg). The aim of the current research was to establish this effect at more realistic dietary levels. EEG was measured in healthy, young participants at baseline and 45, 60, 75, 90 and 105 minutes after ingestion of 50mg L-theanine (n=16) or placebo (n=19). Participants were resting with their eyes closed during EEG recording. There was a greater increase in alpha activity across time in the L-theanine condition (relative to placebo (p+0.05). A second study replicated this effect in participants engaged in passive activity. These data indicate that L-theanine, at realistic dietary levels, has a significant effect on the general state of mental alertness or arousal. Furthermore, alpha activity is known to play an important role in critical aspects of attention, and further research is therefore focussed on understanding the effect of L-theanine on attentional processes.

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... The current study determined that those who consumed coffee most regularly were more likely than tea drinkers to identify as dependent or very dependent, due to the fact that coffee contains one psychoactive substance, caffeine, while tea contains four known psychoactive substancescaffeine, L-theanine, theobromine and theophylline (Li et al., 2020;Nobre et al., 2008). These four substances work together to produce a stimulated response, known as alert relaxation (Nobre et al., 2008). ...
... The current study determined that those who consumed coffee most regularly were more likely than tea drinkers to identify as dependent or very dependent, due to the fact that coffee contains one psychoactive substance, caffeine, while tea contains four known psychoactive substancescaffeine, L-theanine, theobromine and theophylline (Li et al., 2020;Nobre et al., 2008). These four substances work together to produce a stimulated response, known as alert relaxation (Nobre et al., 2008). This 'response' from caffeine alone, as in coffee, is a more wired feeling, which consumers associate more with consumption of caffeine products (Haskell et al., 2007). ...
... Theirs is the only report on the psychological improvement effects of a low dose of theanine. Nobre et al. [19] reported that 50 mg/day of theanine produced a relaxation effect in the resting state. ...
... Following the overall analysis, subgroup analysis according to the participants' backgrounds was conducted. Nobre et al. [19] and Kobayashi et al. [22] examined the relaxation effects of 50 mg theanine; the former observed the participants relaxing, but the latter did not. A clear difference between these studies is the subject background. ...
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L-theanine (theanine), one of the ingredients of green tea, had been proven to have anti-anxiety, anti-stress, memory, cognitive, and sleep improvement effects in most clinical trials. However, these effects have shown efficacy at a dose of 200–400 mg of theanine a day. In this study, we explored the sleep-improving effects of a lower dose (100 mg/day) of theanine. A double-blind, randomized crossover study was conducted on 25 middle-aged and older males. Participants were randomly assigned to Groups A and B. Group A took theanine first, and Group B took theanine later in the intervention period. The participants took theanine/placebo for one week. Electroencephalogram (EEG) parameters were measured with a monitoring device during sleep, and subjective sleep quality after waking up was evaluated using a questionnaire. Following the statistical analysis between interventions, subgroup analyses according to the participants’ background information were conducted on the representative sleep parameters of non-REM sleep, REM sleep, and wakefulness. Of the 25 participants, three withdrew from this study. In the sleep analysis, there was no significant difference in all sleep parameters between the theanine and placebo periods. In particular, the difference in the percentage of nonREM sleep in stage 2 per sleep duration was not significant (p = 0.053). However, subgroup analysis of the results showed that the percentage of non-REM sleep in stage 2 in groups aged <50 years was higher in theanine than that of the placebo, and in groups with green tea consumption habit of <3 to 4 days per week (p = 0.018, 0.048). The intake of 100 mg/day of theanine does not have an effect on sleep improvement. However, subgroup analyses showed that theanine had an improved effect in stage 2 non-REM sleep according to age and green tea consumption habit.
... Bunun sonucunda stresin zararlı etkilerini azaltmak için başka yöntemler gerekmektedir. Magnezyum, özellikle B vitaminleri [2] ve Rhodiola rosea [3] ve yeşil çay [4,5] ekstreleri ile birleştirildiğinde, hayvan modellerinde ve/veya klinik çalışmalarda kullanıldığında strese ilişkin faydalı etkiler göstermiştir. Bunlardan ötürü, yakın zamanda yaklaşık 25 yaşında randomize edilmiş 100 sağlıklı katılımcıyla stresi azaltmak üzere tek doz i) plasebo, ii) magnezyum + B vitaminleri (B6, B9, B12) + yeşil çay (YEŞİL ÇAY), iii) magnezyum + B vitaminleri + rhodiola (RHODIOLA) ve iv) magnezyum + vitaminler + rhodiola + yeşil çay (Teadiola®, KOMBİNASYON) kombinasyonu uygulanan plasebo kontrollü, çift kör bir çalışma yürütülmüştür [6]. ...
... Magnezyum, özellikle B vitaminleri [2] ve Rhodiola rosea [3] ve yeşil çay [4,5] ekstreleri ile birleştirildiğinde, hayvan modellerinde ve/veya klinik çalışmalarda kullanıldığında strese ilişkin faydalı etkiler göstermiştir. Bunlardan ötürü, yakın zamanda yaklaşık 25 yaşında randomize edilmiş 100 sağlıklı katılımcıyla stresi azaltmak üzere tek doz i) plasebo, ii) magnezyum + B vitaminleri (B6, B9, B12) + yeşil çay (YEŞİL ÇAY), iii) magnezyum + B vitaminleri + rhodiola (RHODIOLA) ve iv) magnezyum + vitaminler + rhodiola + yeşil çay (Teadiola®, KOMBİNASYON) kombinasyonu uygulanan plasebo kontrollü, çift kör bir çalışma yürütülmüştür [6]. ...
Article
Zararlı stresi azaltmak, sağlığınızı korumak için önemli bir mücadeledir. Orta derecede stresli sağlıklı yetişkinler üzerinde yapılan yeni, randomize, çift kör, plasebo kontrollü çalışmada (Clinicaltrials.gov: NCT03262376; 25/0817) Magnezyum, B vitaminleri (B6, B9, B12) ve rhodiola ve yeşil çay ekstrelerinden oluşan bir kombinasyonun stresin nesnel ve öznel göstergelerine karşı yararlı etkileri ortaya konulmuştur. Bu her ekstreden daha etkili olmuştur.
... Oscillatory brain activity measured by electroencephalogram (EEG) is an emerging marker for assessing the functional benefits of nutrient intake. Significant modulation of neural EEG activity has been demonstrated after acute intake of both green tea (1)(2)(3) and rhodiola (4). We have recently reported that combining green tea and rhodiola extract and administering with magnesium (Mg) and a B vitamin complex (B 6 , B 9 , and B 12 ) significantly increased resting state frontal midline theta activity under stress conditions compared to placebo, and rhodiola extract combined with Mg and B vitamins (5); post hoc exploratory analysis also demonstrated the combined treatments superiority to green tea in isolation combined with Mg and B vitamins. ...
... The primary analyses were performed in the randomised population, defined as all randomised subjects who received at least one dose of the treatment and for whom a reliable EEG signal could be obtained. A sample size power calculation was conducted based upon previous evidence of the modulation of resting state and attentional performance-related EEG alpha wave activity by L-theanine (1)(2)(3)9). Reported effect sizes ranged from 0.803 to 1.141 (Cohen's d). ...
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Background A combination of green tea, rhodiola and magnesium with B vitamins has previously been reported to significantly increase EEG resting state theta, attenuate subjective stress, anxiety and mood disturbance, and heighten subjective and autonomic arousal under acute psychosocial laboratory stress. Here we examine the capacity of green tea and rhodiola extract administered in combination or in isolation with magnesium and B vitamins to moderate spectral brain activity during attentional task performance under stress. Materials and Methods One-hundred moderately stressed adults received oral supplementation of (i) Mg + B vitamins + green tea + rhodiola; (ii) Mg + B vitamins + rhodiola; (iii) Mg + B vitamins + green tea; or (iv) placebo, in a double-blind, randomised, placebo-controlled, parallel-group design (Clinicaltrials.gov: NCT03262376; 25/0817). Participants completed an attention switching and emotionally threatening attentional bias task after stress induction (Trier Social Stress Test). Spectral alpha and theta brain activity and event related potentials (ERPs) were recorded during cognitive task performance by electroencephalogram (EEG; BioSemi ActiveTwo 64 channel). Results The combined treatment of Mg + B vitamins + green tea + rhodiola significantly increased frontal midline theta vs. placebo and rhodiola in isolation during the attention switching task, specifically in anticipation of a change in task performance parameter. The combined treatment also significantly increased contralateral theta activation in relation to viewing emotionally threatening images in the left (vs. placebo and rhodiola in isolation) and right parietal (vs. placebo) regions. Further, this treatment demonstrated significantly heightened ipsilateral left parietal theta activation in relation to viewing emotionally threatening images. The combined treatment attenuated a decrease in alpha power during the attentional bias task evident in comparator treatments, but this did not reach significance. No significant effects of treatments on behavioural performance or ERP were found. Conclusion The combination of Mg + B vitamins + green tea + rhodiola increased spectral theta brain activity during the execution of two attentional tasks suggestive of a potential to increase attentional capacity under conditions of stress. Further examination of these ingredients in relation to attentional performance under stress is warranted to ascertain if functional benefits suggested by theta activation can be shown behaviourally.
... The sample size was justified upon significant modification of EEG alpha activity following intake of a constituent of green tea. Ltheanine has been demonstrated to induce significant changes in EEG resting state and attentional performance related alpha power [23,[40][41][42]. The effect sizes of L-theanine on EEG alpha activity in these studies ranged from 0.803 to 1.141 (Cohen's d ). ...
... The COMBINED treatment did not moderate resting state alpha activity despite containing equivalent doses of green tea constituents previously shown increase alpha activation [23,40]. Post hoc analyses revealed no significant effects on resting state Alpha across any treatment comparisons. ...
Article
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Background: Magnesium (Mg), green tea and rhodiola extracts have, in isolation, been shown to possess stress and anxiety relieving effects. Green tea and rhodiola have been shown to modulate EEG oscillatory brain activity associated with relaxation and stress perception. The combined capacity of these ingredients to confer protective effects under conditions of acute stress has yet to be examined. We tested the hypothesis that a combination of Mg (with B vitamins) + green tea + rhodiola would acutely moderate the effects of stress exposure. Methods: A double blind, randomised, placebo controlled, parallel group design was employed (Clinicaltrials.gov:NCT03262376; 25/0817). One hundred moderately stressed adults received oral supplementation of either (i) Mg + B vitamins + green tea + rhodiola; (ii) Mg + B vitamins + rhodiola; (iii) Mg + B vitamins + green tea; or (iv) placebo. After supplementation participants were exposed to the Trier Social Stress Test. The effects of the study treatments on electroencephalogram (EEG) resting state alpha and theta, subjective state/mood, blood pressure, heart rate variability and salivary cortisol responses after acute stress exposure were assessed. Results: The combined treatment significantly increased EEG resting state theta (p < .02) - considered indicative of a relaxed, alert state, attenuated subjective stress, anxiety and mood disturbance, and heightened subjective and autonomic arousal (p < .05). Conclusions: Mg, B vitamins, rhodiola and green tea extracts are a promising combination of ingredients that may enhance coping capacity and offer protection from the negative effects of stress exposure.Trial registration: ClinicalTrials.gov identifier: NCT03262376.
... Even though the power of the alpha band increased linearly also in the control group (that may be because the participants were at rest) the enhancement was twofold higher in the experimental group. [9] Cognition There is evidence suggesting positive influence of l-theanine on different aspects of cognition. were observed, while score in the letter fluency was higher among participants with poorer pre-treatment performance. ...
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Introduction: Green tea has been a meaningful element of various cultures among the world for ages and its benefits for human health are widely known. Discovery of its ingredients facilitated the profound research of their positive role and mechanisms of action. One of them – l-theanine - seems to have a multidirectional influence on human health. Methods and materials: A review of chosen literature from PubMed database, GoogleScholar database between the years 2000-2023 was conducted using the following keywords: “theanine”, “theanine cognition”, “theanine brain activity”, “theanine neural activity”, “theanine neuroprotection”, “theanine stress”, “theanine cancer”, “theanine immunity”, “theanine safety”, “theanine caffeine”, “theanine metabolism” Aim of study: Review of current knowledge on l-theanine, its benefits for health, mechanisms of action, possible applications in clinical use and safety. Results: L-theanine has a profitable influence on cognitive performance, stress management, neuroprotection, immunity and exhibits anti-cancer properties while having virtually no detrimental side effects. Conclusions: Further research on application of l-theanine in clinical use is necessary as studies carried out on humans included only a limited number of participants.
... Green tea contains catechins, tannins, phenolic acids, flavanol glycosides, the alkaloid caffeine, and amino acid L-theanine [66,67], which are known capable of a significant effect on the general state of mental alertness or arousal [68], activating adaptive cellular stress responses inducing the production of cytoprotective proteins and protecting neurons in an animal model of Parkinson's disease, Huntington's disease, Alzheimer disease, and ischemia-reperfusion injury [69,70]. Green tea components such as epigallocatechin gallate (EGCG), flavonoids kaempferol, and genistein activate protective mechanisms, including antioxidant and detoxifying enzymes via activation of Nrf2 signaling pathway, and upstream PKC, PI3K, and MAPKs modulation [67,69,70]. ...
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Background: The commonly known assumption that combinations of several herbs in one formulation can have better efficacy due to additive or synergistic effects has not been systematically studied despite some evidence supporting the synergy concept. Study aim: The study aimed to reveal the molecular interactions in situ of host cells in response to the intervention of BHP and justify the benefits of implementing BHP in clinical practice. Results: This overview provides the results of recent clinical and network pharmacology studies of botanical herbal preparations (BHP) of Rhodiola with other plants, including Ashwagandha, Green Tea, Eleutherococcus, Schisandra, Eleutherococcus, Leuzea, Caffeine, Cordyceps, Gingko, Black Cohosh, saffron, and L-carnosine. Conclusions: The most important finding from network pharmacology studies of BHP was the evidence supporting the synergistic interaction of BHP ingredients, revealing unexpected new pharmacological activities unique and specific to the new BHP. Some studies show the superior efficacy of BHP compared with mono-drugs. At the same time, some a priori-designed combinations can fail, presumably due to antagonistic interactions and crosstalk between molecular targets within molecular networks involved in the cellular and overall response of organisms on the intervention. Network pharmacology studies help predict the results of studies to discover new indications and unpredicted adverse events.
... Green tea contains catechins, tannins, phenolic acids, flavanol glycosides, the alkaloid caffeine, and the amino acid L-theanine [69,70], which are known to be capable of significant effects on the general state of mental alertness or arousal [71], activating adaptive cellular stress responses, inducing the production of cytoprotective proteins, and protecting neurons in animal models of Parkinson's disease, Huntington's disease, Alzheimer disease, and ischemia-reperfusion injury [72,73]. Green tea components, such as epigallocatechin gallate (EGCG), flavonoids kaempferol, and genistein activate protective mechanisms, including antioxidant and detoxifying enzymes via activation of Nrf2 signaling pathway, and upstream PKC, PI3K, and MAPKs modulation [70,72,73]. ...
Article
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Background: Despite some evidence supporting the synergy concept, the commonly known assumption that combinations of several herbs in one formulation can have better efficacy due to additive or synergistic effects has yet to be unambiguously and explicitly studied. Study aim: The study aimed to reveal the molecular interactions in situ of host cells in response to botanical hybrid preparations (BHP) intervention and justify the benefits of implementing BHP in clinical practice. Results: This prospective literature review provides the results of recent clinical and network pharmacology studies of BHP of Rhodiola rosea L. (Arctic root) with other plants, including Withania somnifera (L.) Dunal (ashwagandha), (Camellia sinensis (L.) Kuntze (green tea), Eleutherococcus senticosus (Rupr. and Maxim.) Maxim. (eleuthero), Schisandra chinensis (Turcz.) Baill. (schisandra), Leuzea carthamoides (Willd.) DC., caffeine, Cordyceps militaris L., Ginkgo biloba L.(ginkgo), Actaea racemosa L. (black cohosh), Crocus sativus L. (saffron), and L-carnosine. Conclusions: The most important finding from network pharmacology studies of BHP was the evidence supporting the synergistic interaction of BHP ingredients, revealing unexpected new pharmacological activities unique and specific to the new BHP. Some studies show the superior efficacy of BHP compared to mono-drugs. At the same time, some a priori-designed combinations can fail, presumably due to antagonistic interactions and crosstalk between molecular targets within the molecular networks involved in the cellular and overall response of organisms to the intervention. Network pharmacology studies help predict the results of studies aimed at discovering new indications and unpredicted adverse events.
... Total Strength of Bibliographic Coupling Links with Other Authors: The clustered structure highlights research groups that draw upon similar knowledge bases. The largest cluster contains authors in pharmacology and neuroscience like Luo L., Yin Z., and Li J. [58]- [60]. Another incorporates food scientists such as Juneja L.R. and Ozeki M. [61], [62]. ...
... 11 L-Theanine is an amino acid unique to green tea or black tea and is an L-glutamic acid ethyl amide derivative that has attracted attention for its various effects, including suppressing elevated blood pressure 12 and preventing bladder dysfunction. 13 In addition, L-theanine can pass through the blood-brain barrier 14 and is thought to cause relaxation by increasing alpha waves in the brain at 8-13 Hz. 15 This effect suggests that oral administration of L-theanine may be effective in decreasing PMS symp-toms. 16 However, L-theanine's half-life in blood is *1 hour, 17 and it is quickly metabolized and excreted after oral administration. ...
Article
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Background: Premenstrual syndrome (PMS) is experienced by many women who suffer from either its psychological or physical symptoms. Current treatment is limited to symptomatic therapy or oral contraceptives. On the other hand, l-theanine, which has a relaxant effect, has been reported to be useful for PMS, but its short half-life when administered orally makes it less effective. Permeability and properties of transdermal gel containing l-theanine were evaluated as a preclinical study of PMS symptoms relief formulation. Materials and Methods: Lyogel composed of stearic acid, stearyl alcohol, and propylene glycol was selected. The ratio of these components and the preparation method were investigated. Permeation of Strat-M membranes was evaluated by using Franz cells (in vitro). Moreover, lyogel was applied to institute of cancer research mice's backs for 10 days to examine the permeability of l-theanine. Results: l-Theanine solution did not permeate the Strat-M membrane at all in the permeation study, but lyogel allowed l-theanine to permeate. When the composition of lyogel was 4.4:11.1:296 (mmol) for stearic acid, stearyl alcohol, and propylene glycol, l-theanine absorption through Strat-M membrane was better. In skin permeation study using mice, l-theanine was detected in the serum, that is, it was proven that l-theanine penetrated the skin. Conclusion: The preparation of transdermal gels contained l-theanine was investigated as a preclinical study. The skin permeability of semisolid formulations of hydrophobic ointments, hydrophilic ointments, oily creams, creams, and lyogel containing theanine was compared and found that lyogel was the best. The composition of lyogel was also studied to obtain a formulation with good application comfort. Although it is suggested that this lyogel could be tested in clinical studies to determine whether it is effective for relief of PMS symptoms, lyogel may be suitable as an easy-to-use l-theanine-containing formulation for women that can relieve PMS symptoms.
... Studies have focused on the acute relaxing effects by the green tea component L-theanine. Acute intake of ~50 mg of L-theanine increased alpha wave activity in the brain and indicative of relaxation [22]. An acute intake of 200 mg of L-theanine did not affect resting heart rate and heart rate variability metrics [23], and a systematic review by Williams et al [17] suggested an intake of 200-400 mg·day -1 to reduce stress and anxiety in human exposed to stressful conditions. ...
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Introduction: Compared to other green teas, higher intake of multiple phytochemicals is achieved with Matcha green tea consumption. Green tea consumption is known to have metabolic effects but is also consumed for supposed calming effects. The aim of the present study was to examine the effects of encapsulated Matcha green tea on heart rate variability metrics during supine rest, as well as on physiological and metabolic responses during both supine rest and moderate-intensity exercise. Methods: Healthy females (n=8, age: 22±3 yrs, body mass: 68±11 kg, height: 162±5 cm) volunteered. The study employed a placebo-controlled, randomised cross-over design. Time-domain heart rate variability metrics during supine rest (n=5) and physiological and metabolic responses using indirect calorimetry techniques during supine rest and 60-min of moderate-intensity (~ 4-METs) treadmill walking (speed: 4.4±0.5 km·h-1) were measured following 3 weeks of 3 g·day-1 of Matcha green tea or placebo. Results: During supine rest with Matcha green tea, all participants had lower heart rates by 13±7% (P=0.01, d= -1.45), higher mean beat-to-beat RR intervals by 16±9% (P=0.03, d=1.25), higher SDNN by 44±32% (P=0.01, d=0.76) and higher pNN50 by 139±139% (P<0.01, d=1.28). Matcha green tea had no effects on the physiological and metabolic responses during supine rest and moderate-intensity treadmill walking (e.g. respiratory exchange ratio, placebo: 0.78±0.04; Matcha: 0.78±0.03, P=0.87). Fat oxidation during supine rest was correlated (r=0.75, P<0.01) with the moderate-intensity walking induced fat oxidation. Conclusions: In young adult healthy females, Matcha green tea beneficially effects heart rate variability metrics during supine rest indicating an alteration in parasympathetic nervous activity and therefore suggestive of a relaxing effect. Matcha green tea did not change the metabolic responses during supine rest and exercise possibly due to the low respiratory exchange ratio in the female cohort. Future work should address the effectiveness of Matcha green tea during conditions of psychological stress.Keywords: Matcha green tea, heart rate variability, rest, walking, substrate oxidation
... These teas (Camellia sinensis) have anti-inflammatory and weight-loss properties. They also contain L-theanine, which can regulate brain activity and human attention [97]. Black tea's caffeine might also improve mental clarity. ...
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Black tea is frequently consumed worldwide and is renowned for having a distinctive scent. The volatile chemicals in tea are responsible for its aroma, which is important for sensory quality. The enzymatic and non-enzymatic processes that produce the compounds endowing black tea with its distinctive aroma are complex. Black tea is well known for its robust and complex aroma, which can vary based on the type of tea leaves used and processing technologies used. During the production of black tea, several intricate biological and chemical processes contribute to the aroma’s development. Different volatile chemicals are generated during the processing of black tea, which includes withering, rolling, fermentation (enzymatic oxidation), and drying. Various methods have been used to analyze and describe the aroma of black tea. Different methods, such as gas chromatography-mass spectrometry, olfactometry, and solid phase extraction, have been used to assess the fragrance of black tea. These methods evaluate characteristics including fruity, flowery, woody, malty, spicy, and smoky flavors. Phenyl ethyl alcohol, one-octen-3-ol, trans-linalool oxide (furanoid), geraniol, and nonanal are major aroma-active compounds in black tea. Sensory analytic techniques are used to assess black tea’s flavor and scent qualities. This assessment helps figure out the tea’s quality, unique characteristics, and even some unpleasant attributes. Black tea is mostly made from Camellia sinensis and Camellia assamica tea varieties. These two varieties, members of the Camellia genus, differ in their development patterns, leaf sizes, and chemical makeup, impacting how black tea’s scent is formed. When evaluating black tea made from Camellia sinensis and assamica, sensory analysis involved assessing the aroma when the tea was dry and, after brewing, noting any differences from other teas. This review focused on how key aromatic compounds are formed during the tea manufacturing process by Camellia sinensis and Camellia assamica black tea.
... The dominant form of theanine in tea is the L isomer. It is thought that L-theanine crosses the blood-brain barrier and shows its effects directly on the brain within 30 minutes (16). Studies have shown that a number of flavonoids exhibit direct effects on neurological function considering the neurodegenerative disease. ...
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Background: The most common polyphenolic compounds taken up by the organism through the food chain are flavonoids. Known to cross the blood-brain barrier, 7,8-DHF, L-theanine and Fisetin are re-ported to have neuronal effects as well as therapeutic potential for neurodegenerative diseases. How-ever, little is known on their acute effects of neuronal function. This study aims to describe the effects of the mentioned flavonoids on the total ECoG activities and band analyzes of healthy mice. Materials and Methods: For this purpose, 3 different groups consisting of 7 subjects were created for each flavonoid administration. After the baseline electrophysiological recordings, flavonoid administra-tion was performed and acute effects were determined. Results: 7.8-DHF increased the theta, alpha and beta band activities while decreasing the total ECoG power. L-theanine and Fisetin did not significantly alter the total ECoG activity. However, L-theanine statistically increased theta, alpha and beta band activities. Conclusions: In conclusion, our data showed that flavonoids could acutely modulate the ECoG respons-es in a band specific manner. They can be considered as candidate molecules for drug discovery studies for central nervous system disorders.
... Additionally, THE's anxiolytic effects have been observed to enhance hippocampal activity [58]. Moreover, studies have indicated that THE supplementation modulates alpha activity and plays a significant role in tasks requiring attention in electroencephalogram studies [59,60]. Furthermore, THE has been reported to have beneficial effects on mental state [61], including sleep quality [62]. ...
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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.
... Catechins are famous for their antiviral properties, which can, for example, interfere with the replication cycle of DNA viruses and keep people healthier ( Figure 1C) [5]. L-theanine is recognized for its anxiety-relieving effects as it increases dopamine levels and increases the production of alpha waves, which makes people more relaxed ( Figure 1B) [6,7]. ...
Article
Tea is a widely-consumed beverage, and different types of tea can be produced depending on their oxidation levels. However, how different types of tea and brewing water temperature can affect health has not been considered. This investigation studied how compounds in tea such as caffeine, catechins, and L-theanine, were different in green tea, Bao Chong tea, and black tea, as well as in Bao Chong tea brewed with different water temperatures (25ºC, 45ºC, 75ºC, 90ºC) using NMR analysis. The results showed that Bao Chong Tea had the highest caffeine, catechins, and L-theanine content, followed by green tea and then black tea. The best temperature for brewing tea to produce caffeine, catechins and L-theanine was between 45ºC and 75ºC, and all chemical contents were reduced greatly at 90ºC. A better understanding of the relationship between tea and its chemical contents will allow people to have better knowledge of their food intake, and possibly allow people to choose accordingly.
... We designed the entire study, as shown in Fig. 1. From the literature, we determined highly effective concentrations as high doses and less effective concentrations as low doses to neuronal cells [17][18][19][20] . The concentrations used for treatment are listed in Table 1. ...
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Adenosine triphosphate (ATP) is an extracellular signaling molecule that mainly affects the pathophysiological situation in the body and can be sensed by purinergic receptors, including ionotropic P2X7. Neuronal stem cells (NSCs) remain in adult neuronal tissues and can contribute to physiological processes via activation by evoked pathophysiological situations. In this study, we revealed that human-induced pluripotent stem cell-derived NSCs (iNSCs) have ATP-sensing ability primarily via the purinergic and ionotropic receptor P2X7. Next, to develop a machine learning (ML)-based screening system for food-derived neuronal effective substances and their effective doses, we collected ATP-triggered calcium responses of iNSCs pretreated with several substances and doses. Finally, we discovered that ML was performed using composite images, each containing nine waveform images, to achieve a better ML model (MLM) with higher precision. Our MLM can correctly sort subtle unidentified changes in waveforms produced by pretreated iNSCs with each substance and/or dose into the positive group, with common mRNA expression changes belonging to the gene ontology signatures.
... The main, free amino acid, theanine in tea accounts for nearly 50% of total free amino acids found in tea, or nearly 1-2% (dry weight) of green tea, which contributes to an umami taste. Furthermore, more than six hundreds of volatile compounds contribute to the aroma properties of tea (Nobre et al., 2008). In the black tea manufacturing process, the oxidation of polyphenols leads to the formation of dimeric and polymeric polymers, including theaflavins (TF, orange-red), thearubigins (TR, dark brown), theaflavins acids, and proanthocyanidin polymers (Wickremasinghe,1978;Liang et al., 2003;Chaturvedula & Prakash, 2011). ...
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Tea is the most consumed beverage in the world next to water. Organic tea manufacturing has increased worldwide during recent decades owing to the benefits for human well-being and the environment, regardless of the overall lower yields of organic systems. Organic tea is richer in (+)-catechin (C), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-gallate (EGCG), (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), and amino acids, including proline and gamma-aminobutyric acid, than processed tea from conventional agricultural systems. The majority of free amino acids, including theanine, are lower in organic tea. Tea quality is strongly correlated with catechins, caffeine, volatile compounds, and amino acids in harvestable tea shoots. Reliable information on the quality of tea comparing conventional and organic systems is scarce because of the investigational strains in comparing these two systems from different sites. This mini-review highlights the recently published evidence on quality parameters of organic and conventionally grown tea and offers readers scientific evidence as to whether the differentiation is possible.
... 37 When 50 mg of theanine is ingested, alpha waves appear 40 min later. 38,39 The blood concentration peak of theanine occurs later than that of caffeine; therefore, after ingesting the test food, caffeine's central nervous system stimulative effect would be temporarily greater than that of theanine. This is considered the reason that the sleep onset latency was not shortened in the TC group compared with the caffeine group. ...
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Energy drinks take advantage of caffeine's effects on wakefulness and performance; however, excessive intake has a negative effect on sleep. Green tea is consumed worldwide and has both a stimulating effect from caffeine and a calming or relaxing effect from theanine. Theanine reduces the excitotoxicity of caffeine. This study evaluated whether theanine improves the sleep quality worsened by caffeine in healthy young women. Sleep latency, sleep time, wake after sleep onset (WASO) time, and the number of WASOs were measured. A crossover study was performed using four treatment groups: theanine (50 mg), caffeine (30 mg), combined theanine and caffeine (TC), and placebo. The sleep stage was determined using electroencephalograms, and cerebral blood flow was measured using near-infrared spectroscopy. The caffeine group showed a significant increase in the WASO time compared with the placebo group; no difference was observed between the theanine or TC group and the placebo group. There were no differences in the sleep-onset latency or number of WASOs between the theanine, caffeine, or TC groups and the placebo group. In combination with theanine, only the caffeine-induced increase in the WASO time was suppressed. Our results suggest that theanine can reduce caffeine's effects on sleep quality.
... 4,18 Available prescription and non-prescription treatment modalities cover a wide variety of products that demonstrates the prevalence of the condition and difficulties associated with treating this behavior. 4,14,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] Prescription medications to treat CTA fall into 3 main classes: benzodiazepines (BZDs), tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). 4 One of the most recommended conventional treatments of CTA is alprazolam given 30 minutes to 2 hours before a storm and every 4-6 hours during a storm. ...
Article
Canine thunderstorm aversion (CTA) is a significant challenge to pets, owners, and veterinarians. The objective of this research was to determine if traditional Chinese veterinary medicine (TCVM) treatment with acupuncture, Chinese herbal medicine, basic desensitization and counterconditioning (DSCC) with a behavior modification drug, could lessen the severity of CTA in dogs. A total of 23 dogs that exhibited behaviors typical of thunderstorm aversion were enrolled in the study. At study start, all dogs received a TCVM Pattern diagnosis and were treated with Pattern-specific Chinese herbal medicine and acupuncture points. In addition, owners received DSCC behavior modification protocols and a conventional drug (alprazolam) to be used as needed during thunderstorms. Dogs were examined once a month for 4 months and Chinese herbal medicine formulations and acupuncture treatment adjusted as TCVM Patterns changed. After 120 days of treatment, the mean±SD improvement in overall thunderstorm aversion behaviors in study participants was 77.2%±27.7% (p < 0.0001). This result was significantly greater than 52% (p = 0.002), a reported mean improvement percentage for conventional treatment only, after 4 months. Six of the 7 individual aversion behaviors (panting, pacing, trembling, hiding, excess salivation, excess vocalization) had a significant reduction (range: p =0.046 to p = 0.008) over the course of treatment. The study results demonstrated that integrative management of CTA with TCVM Pattern-specific treatments combined with a conventional rescue drug and behavior modification improves CTA behaviors and suggests greater efficacy than conventional medical management only. Randomized controlled trials are warranted to validate these preliminary findings.
... Specific components found in tea, including the amino acid L-theanine are thought to aid sleep quality and induce relaxing effects [48]. L-theanine is thought to modulate aspects of human brain function including increasing alpha frequency band activity, and relaxing the mind [49]. Some research has shown that L-theanine can counteract and partially reverse reductions in slow-wave sleep induced by caffeine [50]. ...
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Tea is popular global beverage and abundant provider of biologically active plant molecules which have been attributed to its health properties. Relationships between tea drinking and certain aspects of health have been the subject of past reviews. The present systematic review focuses on tea consumption in relation to psychological stress and the challenges of stress and anxiety on sleep health. Publications were searched up to 21st September 2022, in the PubMed database along with references of original articles. Thirty-three publications were included in the main review-17 human trials and 16 mechanistic studies. Human trials were graded to assess quality using the Jadad scale. Overall, a growing body of evidence suggests that tea (including green and oolong) and herbal infusions, at relatively low intakes (around 1 to 2 cups daily), could help to facilitate sleep, alleviate psychological stress and anxiety, primarily by facilitating relaxation. Evidence for black tea, German Chamomile, Lavender, Rose, Jasmine, and Passionflower tea is emerging and looks promising. Ongoing research is needed in the form of randomised controlled trials to build on these provisional findings.
... Theaflavins inhibits xanthine oxidation and nitric oxidase action responsible for production of free radicals (Fatima et al., 2013). It contains L-theanine which raises GABA (gamma-aminobutyric acid) levels, promoting relaxation and releasing alpha waves in the brain, which improves relaxation, focus, and creativity (Nobre et al., 2008). It also contains caffeine (methyl xanthine), a psychostimulant that boosts alertness but is detrimental to one's health if consumed in excess. ...
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The current COVID-19 predicament necessitates a greater emphasis on developing immunity. Herbal teas are abundant in antioxidants which are important for strengthening the immune system. Hot water decoction of Hibiscus rosa sinensis flowers (red tea), Clitoria ternatea flowers (blue tea) and commercially available black tea were evaluated by comparing for in vitro antioxidant and anti-inflammatory properties. Anthocyanin pigment in red, blue, and black tea demonstrated Rf values of 0.52, 0.86 and 0.78 respectively. Blue and black teas exhibited dominance of polyphenols, flavonoids, tannins, glycosides, terpenoids, saponins as compared to red tea. The highest total phenolic (12.25 ± 0.245 mg GAE/gm extract-1) and flavonoid (15.84 ± 0.268mg QE/gm extract-1) content were observed with black and blue tea respectively. Blue tea, and black tea extracts exhibited FRPA values of 1.81 ± 0.413 mg and 1.93 ± 0.178 mg AAE per gram extract-1 respectively. Black tea exhibits the highest antioxidant capacity in reducing molybdate ions (1.94 ± 0.354 mg AAE per gram extract-1) followed by blue tea (1.56 ± 0.199 mg AAE per gram extract-1). Blue tea extract at a very low concentration showed highest percentage hemolytic inhibition (57.14 ± 0.567%). According to the study, blue tea is a rich source of antioxidants with significant anti-inflammatory properties. The research may offer a valuable supplementary strategyfor its therapeutic applications.
... The ingredient l-theanine (g-glutamylethylamide), which affects the taste of the tea, is the most abundant water soluble non-proteinous amino acid component in green tea and accounts for more than 50% of the total free amino acids (4). l-Theanine constitutes ~25-60 mg per 200 mL of green tea, ~1%-2% of the dry weight of green tea leaves, with the L isomer being the predominant form of theanine in green tea (5). l-Theanine is easily absorbed into the bloodstream and small intestine, then transports through the blood-brain barrier into the brain. ...
Article
l-Theanine, the most abundant amino acid component in green tea, has anti-stress effects and refreshes the mental state. A recent study demonstrated that l-arginine, the second most abundant amino acid in green tea, might enhance the anti-stress effects of l-theanine. The aim of this study was to evaluated the effects of combined ingestion of l-theanine and l-arginine on psychological stress in humans. A randomized placebo-controlled trial was conducted including 120 healthy young adults (mean age 22.4 y, 63.3% female). Subjects were randomly assigned to theanine (200 mg l-theanine), combined theanine/arginine (200 mg l-theanine, 50 mg l-arginine), or placebo groups. After consuming a test beverage, we administered a stress-loading test (Uchida-Kraepelin performance test) and performed salivary alpha-amylase activity (sAA) measurements to assess the physiological stress response at 0 min (immediately after), 5 min, and 15 min. The changes in sAA at 15 min after the stress-loading test were −2.75 (11.2) kIU/L in the theanine/arginine group, −0.40 (11.5) kIU/L in the theanine group, and 6.95 (18.6) kIU/L in the placebo group. The values in the theanine/arginine (p=0.007) and theanine (p=0.02) groups differed significantly from those in the placebo group. However, the difference between theanine/arginine and theanine groups, was not statistically significant (p=0.74). From this study, no clear conclusion could be drawn regarding the potentiating effect of theanine and arginine combined ingestion on anti-stress effects in human.
... In humans, L-theanine peaks in plasma at about 50 min after ingestion in purified form, has an elimination half-life of about 65 min [6], and is completely cleared of plasma after 24 h [7]. Human electroencephalographic (EEG) studies show that a 200-mg dose of Ltheanine increases the resting state alpha activity starting from around 40 min following ingestion, indicating that L-theanine reaches therapeutic concentrations in the brain by that time [8,9]. ...
Article
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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.
... Le magnésium, en particulier lorsqu'il est associé aux vitamines B [2] et à des extraits de Rhodiola rosea [3] et de thé vert [4,5], a montré des effets bénéfiques sur le stress dans des modèles animaux et/ou des études cliniques. Par conséquent, une récente étude contrôlée contre placebo et en double aveugle a randomisé 100 volontaires en bonne santé, âgés d' environ 25 ans, pour recevoir une seule dose de i) placebo, ii) magnésium + vitamines B (B6, B9, B12) + thé vert (THÉ VERT), iii) magnésium + vitamines B + rhodiola (RHODIOLA) et iv) magnésium + vitamines B + rhodiola + thé vert (Teadiola®, ASSOCIATION) afin de remédier au stress [6]. ...
Article
La réduction du stress négatif est un enjeu majeur pour préserver le bien-être. Une récente étude randomisée, en double aveugle et contrôlée contre placebo, menée sur des adultes en bonne santé et modérément stressés (Clinicaltrials.gov: NCT03262376 ; 25/0817) démontre les effets bénéfiques d’une association de magnésium, vitamines B (B6, B9, B12) et extraits de rhodiola et de thé vert par rapport à des indicateurs de stress objectifs et subjectifs. Elle a été plus efficace que l’un ou l’autre extrait seul.
... Το μαγνήσιο, ιδιαίτερα όταν συνδυάζεται με τις βιταμίνες B [2] και τα εκχυλίσματα ροδιόλας της ροδόχρου [3] και πράσινου τσαγιού [4,5], έχει δείξει ωφέλιμες επιδράσεις σε σχέση με το στρες, σε ζωικά μοντέλα ή/και κλινικές μελέτες. Ως εκ τούτου, μια πρόσφατη ελεγχόμενη με εικονικό φάρμακο, διπλά τυφλή μελέτη τυχαιοποίησε 100 υγιείς εθελοντές ηλικίας περίπου 25 ετών για να λάβουν μια εφάπαξ δόση i) εικονικού φαρμάκου, ii) μαγνησίου + βιταμινών B (B6, B9, B12) + πράσινου τσαγιού (ΠΡΑΣΙΝΟ ΤΣΑΙ), iii) μαγνησίου + βιταμινών B + ροδιόλας (ΡΟΔΙΟΛΑ) και iv) μαγνησίου + βιταμινών B + ροδιόλας + πράσινου τσαγιού (Teadiola®, ΣΥΝΔΥΑΣΜΟΣ) ως τρόπο αντιμετώπισης του στρες [6]. ...
Article
Η μείωση του επιβλαβούς στρες αποτελεί βασική πρόκληση για τη διατήρηση της ευεξίας. Μια πρόσφατη, τυχαιοποιημένη, διπλά τυφλή, ελεγχόμενη με εικονικό φάρμακο μελέτη σε υγιείς ενήλικες με μέτριο επίπεδο στρες (Clinicaltrials.gov: NCT03262376; 25/0817) δείχνει ωφέλιμες επιδράσεις ενός συνδυασμού μαγνησίου, βιταμινών B (B6, B9, B12) και εκχυλισμάτων ροδιόλας και πράσινου τσαγιού επί των αντικειμενικών και υποκειμενικών δεικτών του στρες. Ο συνδυασμός ήταν πιο αποτελεσματικός από ό,τι το καθένα από τα εκχυλίσματα μόνο του.
... Magnesium, insbesondere in Kombination mit B-Vitaminen [2] sowie Extrakten aus Rhodiola rosea [3] und grünem Tee [4,5], hat in Tiermodellen und/oder klinischen Studien positive Wirkungen bezogen auf Stress gezeigt. Daher wurden in einer kürzlich durchgeführten placebokontrollierten Doppelblindstudie 100 gesunde Freiwillige im Alter von etwa 25 Jahren randomisiert und erhielten eine einmalige Dosis i) Placebo, ii) Magnesium + B-Vitamine (B6, B9, B12) + grüner Tee (GRÜNER TEE), iii) Magnesium + B-Vitamine + Rhodiola (RHODIOLA) und iv) Magnesium + B-Vitamine + Rhodiola + grüner Tee (Teadiola®, KOMBINATION) als Mittel gegen Stress [6]. ...
Article
Der Abbau von schädlichem Stress ist eine zentrale Herausforderung für die Erhaltung des Wohlbefindens. Eine kürzlich durchgeführte randomisierte, doppelblinde, placebokontrollierte Studie mit mäßig gestressten gesunden Erwachsenen (Clinicaltrials.gov: NCT03262376; 25/0817) zeigt die positiven Auswirkungen einer Kombination aus Magnesium, B-Vitaminen (B6, B9, B12) sowie Rhodiola und grünem Tee auf objektive und subjektive Stressindikatoren. Die Kombination war wirksamer als die jeweiligen Extrakte allein.
... A magnézium, különösen a B-vitaminokkal [2], valamint a Rhodiola rosea [3] és a zöld tea kivonataival [4,5] kombinálva a stresszel kapcsolatos jótékony hatásokat mutattak ki állatmodellek és/vagy klinikai vizsgálatok során. Ezért egy nemrégiben végzett, placebo-kontrollos, kettős vak vizsgálatban 100 fő, körülbelül 25 éves körüli egészséges önkéntest randomizáltak olyan módon, hogy egyetlen adagot kaptak i) placebót, ii) magnéziumot + B-vitamint (B6, B9, B12) + zöld teát (ZÖLD TEA), iii) magnéziumot + B-vitaminokat + rhodiola (RHODIOLA) és iv) magnéziumot + B-vitamin + rhodiola + zöld tea (Teadiola®, KOMBINÁCIÓ) stresszoldóként [6]. ...
Article
Egy nemrégiben végzett, randomizált, kettős vak, placebo-kontrollos közepesen stresszes vizsgálat, egészséges felnőtteken (Klinikai vizsgálatok, clinictrials.gov: NCT03262376; 25/0817) bemutatja a magnézium, a B-vitaminok (B6, B9, B12), valamint a rhodiola és zöld tea kivonatok jótékony hatását a stressz objektív és szubjektív mutatóival szemben. Hatékonyabb volt, mint bármelyik kivonat önmagában.
... El magnesio, especialmente cuando se combina con vitaminas del grupo B [2] y con extractos de Rhodiola rosea [3] y de té verde [4,5], ha demostrado efectos beneficiosos contra el estrés en modelos animales y/o en estudios clínicos. Por ello, en un reciente estudio doble ciego, controlado con placebo, 100 voluntarios sanos de unos 25 años fueron aleatorizados para recibir una dosis única de: i) placebo, ii) magnesio + vitaminas del grupo B (B6, B9, B12) + té verde (TÉ VERDE), iii) magnesio + vitaminas B + rodiola (RHODIOLA), y iv) magnesio + vitaminas B + rodiola + té verde (Teadiola®, COMBINACIÓN) como remedio para el estrés [6]. ...
Article
La reducción del estrés nocivo es un reto clave para preservar el bienestar. Un estudio reciente, aleatorizado, doble ciego y controlado con placebo realizado en personas adultas sanas con un nivel de estrés moderado (Clinicaltrials.gov: NCT03262376; 25/0817) ha demostrado que los efectos beneficiosos de una combinación de magnesio, vitaminas del grupo B (B6, B9, B12), extractos de rodiola y té verde en los indicadores objetivos y subjetivos del estrés fueron más eficaces que con cualquiera de los dos extractos por separado.
... Magnesium, particularly when combined with B vitamins [2] and extracts of Rhodiola rosea [3] and of green tea [4,5] have shown beneficial effects related to stress in animal models and/or clinical studies. Therefore, a recent placebo-controlled, double-blind study randomized 100 healthy volunteers aged approximately 25 years to receive a single dose of i) placebo, ii) magnesium + B vitamins (B6, B9, B12) + green tea (GREEN TEA), iii) magnesium + B vitamins + rhodiola (RHODIOLA), and iv) magnesium + B vitamins + rhodiola + green tea (Teadiola®, COMBINATION) as a remedy for stress [6]. ...
Article
Reducing harmful stress is a key challenge to preserve well-being. A recent, randomized, double-blind, placebo-controlled study in moderately stressed healthy adults (Clinicaltrials.gov: NCT03262376; 25/0817) demonstrates beneficial effects of a combination of magnesium, B vitamins (B6, B9, B12) and rhodiola and green tea extracts against objective and subjective indicators of stress. It was more effective than either extract alone.
... Il magnesio, soprattutto quando usato in combinazione con le vitamine del gruppo B [2] e gli estratti di Rhodiola rosea [3] e tè verde [4,5], ha evidenziato effetti benefici in relazione allo stress in modelli animali e/o studi clinici. Un recente studio controllato con placebo, in doppio cieco ha dunque randomizzato 100 volontari sani di circa 25 anni di età a ricevere una singola dose di i) placebo, ii) magnesio + vitamine del gruppo B (B6, B9, B12) + tè verde (TÈ VERDE), iii) magnesio + vitamine del gruppo B + rodiola (RODIOLA) e iv) magnesio + vitamine del gruppo B + rodiola + tè verde (Teadiola®, COMBINAZIONE) come rimedio per lo stress [6]. ...
Article
La riduzione dello stress nocivo è una sfida chiave per la salvaguardia del benessere. Un recente studio randomizzato, in doppio cieco, controllato con placebo in adulti sani con stress moderato (Clinicaltrials.gov: NCT03262376; 25/0817) dimostra gli effetti benefici di una combinazione di magnesio, vitamine del gruppo B (B6, B9, B12) ed estratti di rodiola e tè verde sugli indicatori oggettivi e soggettivi di stress. La combinazione si è dimostrata più efficace rispetto ai singoli estratti da soli.
... Magnez, w szczególności w skojarzeniu z witaminami B [2] i ekstraktami z różeńca górskiego [3] i zielonej herbaty [4,5], wykazywał działanie łagodzące stres w modelach zwierzęcych i (lub) badaniach klinicznych. Z tego powodu do niedawnego badania prowadzonego metodą podwójnie ślepej próby z grupą kontrolną placebo zrandomizowano 100 zdrowych ochotników w wieku około 25 lat, którzy otrzymywali pojedyncze dawki: i) placebo, ii) magnezu + witamin z grupy B (B6, B9, B12) + zielonej herbaty (ZIELONA HERBATA), iii) magnezu + witamin z grupy B + różeńca (RÓŻENIEC), oraz iv) magnezu + witamin z grupy B + różeńca + zielonej herbaty (produkt Teadiola®, LECZENIE SKOJARZONE) jako środka o działaniu przeciwstresowym [6]. ...
Article
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Zredukowanie szkodliwego stresu jest kluczowym wyzwaniem, aby móc zachować dobre samopoczucie. Niedawne badanie przeprowadzone metodą podwójnie ślepej próby, z randomizacją i grupą kontrolną placebo u zdrowych dorosłych odczuwających umiarkowany stres (Clinicaltrials.gov: NCT03262376; 25/0817) wykazało korzystny wpływ stosowania połączenia magnezu, witamin z grupy B (B6, B9, B12) oraz ekstraktów z różeńca i zielonej herbaty na obiektywne i subiektywne wskaźniki stresu. Połączenie to było skuteczniejsze niż stosowanie któregokolwiek z ekstraktów oddzielnie.
... [4,5], demonstrou ter efeitos benéficos relacionados com o stress em modelos animais e/ou estudos clínicos. Por isso, um estudo recente com dupla ocultação e controlado por placebo recrutou aleatoriamente 100 voluntários saudáveis com uma idade aproximada de 25 anos de vida para receber uma única dose de i) placebo, ii) magnésio + vitaminas B (B6, B9, B12) + chá verde (CHÁ VERDE), iii) magnésio + vitaminas B + rhodiola (RHODIOLA) e iv) magnésio + vitaminas B + rhodiola + chá verde (Teadiola®, COMBINAÇÃO) como remédio para o stress [6]. ...
Article
A redução do stress nocivo é um desafio fundamental para preservar o bem-estar. Um estudo recente aleatorizado com dupla ocultação e controlado por placebo em adultos saudáveis com stress moderado (Clinicaltrials.gov: NCT03262376; 25/0817) demonstra os efeitos benéficos de uma combinação de magnésio, vitaminas B (B6, B9, B12) e extratos de rhodiola e chá verde em comparação com indicadores objetivos e subjetivos do stress. Foi mais eficaz do que qualquer um dos extratos por si só.
... Its potential beneficial health effects are reported to derive from several bioactive constituents that are associated with improvements in antioxidant responses (Li et al. 2012), cognitive function and numerous cardiovascular benefits (Juneja et al. 1999;Vuong et al. 2011;Williams et al. 2018). Additionally, the consumption of GT is associated with eliciting a relaxation response, which is predominately ascribed to the unique amino acid L-theanine (L-THE) (Juneja et al. 1999;Nobre et al. 2008). L-THE is a non-proteinogenic amino acid commonly found in GT tea leaves, which in its pure form of is described as a white crystalline powder with no odour and a slightly sweet taste that presents the unique 'umami' flavour sensation (Cooper 2012;Juneja et al. 1999;Narukawa et al. 2014). ...
Article
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The non-proteinous amino acid L-theanine (L-THE) is associated with a range of health benefits including improvements in immune function, cardiovascular outcomes and cognition. The aims of this study were to develop a food product (mango sorbet; ms-L-THE) containing physiologically relevant doses of L-THE (0.2/100 g w/w) and determine its antioxidant, physicochemical and sensory properties in comparison to a mango sorbet without L-THE (ms). Total phenolic and flavanol content, and antioxidant analysis (DPPH, FRAP and ABTS) were determined spectrophotometrically. Both products were also evaluated for acceptability and likeability in healthy participants using the 9-point hedonic scale. Any differences that could be caused by the addition of L-THE were examined using the triangle test. Results indicated no significant differences between ms-L-THE and ms in taste of the products (p > 0.05), and the ms-L-THE was well received and accepted as a potential commercial product. Findings of the DPPH assay indicated significant difference between the two products (p < 0.05). In conclusion, we have successfully created a mango sorbet that contains a potentially physiologically relevant concentration of L-THE with antioxidant properties that could be used as a novel method of L-THE delivery to clinical and healthy populations.
... In humans, L-theanine is absorbed through the small intestine and shows a peak plasma concentration 0.8 hours after ingestion, and this concentration is dose-dependent [10,11]. Ltheanine crosses the blood brain barrier and shows EEG changes starting around 40 minutes after oral administration [12,13]. It has a plasma elimination half-life of about 65 minutes, and is completely eliminated from plasma within 8 hours [11]. ...
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Tea (Camellia sinensis) is a historically and economically important beverage for Sri Lanka; and is traditionally believed to have relaxing or calming effects. Some evidence attributes these effects to a constituent of tea leaves; L-theanine, a non-protein-forming amino acid structurally similar to glutamic acid. Over the years, research has found L-theanine to also have effects on various cognitive functions, including attention. This review focuses on the research conducted thus far on the acute effects of L-theanine on neurobehavioral, neurophysiological, and functional neuroimaging indices, cognition and attention. Despite the heterogeneity of testing paradigms across studies, experimental evidence increasingly suggests that L-theanine could improve visual selective attention. Contrary to traditional belief, the amount of L-theanine in a cup of tea (4.5-22.5mg) seems to cause no significant effects; and attentional improvement is more prominent with much higher doses (100-500mg). This makes it worth exploring the possibility of enriching tea with L-theanine, while preserving the unique flavour of the product. L-theanine has an additive effect with caffeine in enhancing attention, but unlike caffeine, L-theanine can be ingested in high doses with no risk of adverse effects, tolerance or dependence. The evidence on attentional effects of L-theanine is almost entirely based on healthy samples who have undergone laboratory-based attentional tasks that employed abstract stimuli. When translating these laboratory findings to real-life scenarios, incorporating more real-life-based stimulus paradigms (i.e., simulated driving scenarios) is warranted. The clinical relevance of L-theanine research could also be improved by exploring the effects of L-theanine in cognitively compromised groups of individuals.
... This desire has resulted in new consumer products and marketing aimed at food with health benefits in addition to basic nutrition [33,34]. The most widely studied and regarded health benefit of theanine is the role it plays in mood and concentration [35]. It is well accepted that theanine can induce relaxation without drowsiness, helping to focus the mind, due to the stimulation of Gamma Amino Butyric Acid (GABA), serotonin and tryptophan production [36,37]. ...
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Gyokuro is a style of Japanese green tea produced by employing agricultural shading in the weeks before harvest. This method results in a tea product with different organoleptic and chemical properties than common Japanese green tea. In an effort to yield the highest quality and commercially valuable green tea product, the present study explores the influence of shading treatments and the duration of shading on the natural biochemistry of the green tea plant. This study applied shading treatments at light intensity conditions of 40%, 16%, 10% and 1% of available ambient light and the application of a red-colored shade cloth of 60% opacity. The Quality Index Tool was used to measure the quality and commercial value of the green tea, using individual target constituents (theanine, caffeine and the catechins) quantified from HPLC analysis. This study shows that very high levels of total visible spectrum light shading (~99%) is required to achieve improvements in quality and commercial value. Specifically, this improvement is a direct result of changes in the mood- modifying bioactive metabolites theanine and caffeine. This study concludes that in green tea growing regions with more hours of sunlight per year, such as on the Central Coast of Australia, more intense shading will achieve products with improved quality and commercial value, which has more potential to be marketed as a functional ingredient.
... However, increasing attention in recent years has focused on L-theanine, a unique amino acid contained in green tea. Since L-theanine crosses the blood-brain barrier [5], its psychological effects have been studied [6,7]. For instance, L-theanine increases alpha-wave activity, indicating effects in increasing relaxing and reducing anxiety [8]. ...
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Chronic sympathetic hyperactivity is known to affect metabolism and cause various organ damage including bladder dysfunction. In this study, we evaluated whether L-theanine, a major amino acid found in green tea, ameliorates bladder dysfunction induced by chronic sympathetic hyperactivity as a dietary component for daily consumption. Spontaneously hypertensive rats (SHRs), as an animal model of bladder dysfunction, were divided into SHR–water and SHR–theanine groups. After 6 weeks of oral administration, the sympathetic nervous system, bladder function, and oxidative stress of bladder tissue were evaluated. The mean blood pressure, serum noradrenaline level, and media-to-lumen ratio of small arteries in the suburothelium were significantly lower in the SHR–theanine than in the SHR–water group. Micturition interval was significantly longer, and bladder capacity was significantly higher in the SHR–theanine than in the SHR–water group. Bladder strip contractility was also higher in the SHR–theanine than in the SHR–water group. Western blotting of bladder showed that expression of malondialdehyde was significantly lower in the SHR–theanine than in the SHR–water group. These results suggested that orally administered L-theanine may contribute at least partly to the prevention of bladder dysfunctions by inhibiting chronic sympathetic hyperactivity and protecting bladder contractility.
... The current study investigated the effects of a single 200 mg dose of AlphaWave Ò L-Theanine. A previous study investigated the effects of lower, 50 mg doses of L-theanine on alpha power and showed increases in a time-dependent manner for 105 min [24]. The current work observed relaxation n number of participants, SD standard deviation, Min minimum, Max maximum effects that extended 3 h post-dose, therefore demonstrating the efficacy of AlphaWave Ò L-Theanine for longer periods of time than previously shown. ...
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... Clinical trials show that L-theanine, a unique component in green tea, can ameliorate the stress-related symptoms and depressive disorders [13]. Evidence from human electroencephalograph (EEG) studies shows that L-theanine significantly increases activity in the alpha frequency band which indicates mental relaxation [14]. In sum, these observations support the argument that tea consumption has benefits in relaxing mood and preventing depression. ...
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The metabolism of theanine, one of the major amino acid components in tea (Camellia sinensis), was studied in rats. High-performance liquid chromatography (HPLC) with fluorometric detection was used to evaluate the nature of theanine's metabolites in plasma, urine, and tissues. In the urine samples collected after administration of 100, 200, and 400 mg each of theanine, intact theanine, L-glutamic acid, and ethylamine, these compounds were detected in a dose-dependent manner. When 200 mg of theanine was orally administered to rats, the plasma concentrations of theanine and ethylamine reached their highest levels about 0.5 and 2 h after administration, respectively. It seems most likely that the enzymatic hydrolysis of theanine to glutamic acid and ethylamine was accomplished in the kidney. These results indicate that orally administered theanine is absorbed through the intestinal tract and hydrolyzed to glutamic acid and ethylamine in the rat kidney.
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Our neurophysiological model of anticipatory behaviour (e.g. Acta Psychol 101 (1999) 213; Bastiaansen et al., 1999a) predicts an activation of (primary) sensory cortex during anticipatory attention for an upcoming stimulus. In this paper we attempt to demonstrate this by means of event-related desynchronization (ERD). Five subjects performed a time estimation task, and were informed about the quality of their time estimation by either visual or auditory stimuli providing Knowledge of Results (KR). EEG and MEG were recorded in separate sessions, and ERD was computed in the 8-10 and 10-12 Hz frequency bands for both datasets. Both in the EEG and the MEG we found an occipitally maximal ERD preceding the visual KR for all subjects. Preceding the auditory KR, no ERD was present in the EEG, whereas in the MEG we found an ERD over the temporal cortex in two of the 5 subjects. These subjects were also found to have higher levels of absolute power over temporal recording sites in the MEG than the other subjects, which we consider to be an indication of the presence of a 'tau' rhythm (e.g. Neurosci Lett 222 (1997) 111). It is concluded that the results are in line with the predictions of our neurophysiological model.