SCIENTIFIC RESEARCH ON L-THEANINE

 

L-theanine is an amino acid that can be found in tea and mushrooms. Amino acids are chemical substances that constitute the building blocks of human body since they create proteins crucial for the production of insulin, adrenaline and neurotransmitters. They also support cellular regeneration and help gain muscle mass. As numerous American and Australian studies showed, L-theanine in conjunction with caffeine – both contained in matcha – positively affects cognitive functions, concentration and mood (1)(2). L-theanine partially soothes the stimulating effect of caffeine and lowers blood pressure. As a result, and what Newcastle University studies proved (3), drinking a cup of matcha makes us feel more energized, but also less nervous.

Effective learning and memory improvement

A research published in the American Journal of Clinical Nutrition shows how matcha tea improves attention and helps to concentrate on a task. People who within 1.5 h had drunk 2 or 3 cups of green tea achieved better results in the learning practice than consumers treated with a placebo drink (4). Thanks to its stimulating effect, green tea boosts creative thinking (5).

L-theanine positively affects memory, especially the working one. After drinking green tea, participants in the study carried out by the University of Basel solved some tasks designed to test hypothesis. Then professor Stefan Borgwart at the Psychiatric Clinic, who was leading the study, used the MRI to check the brain activity of the participants. He noticed that there was a modulation of the connectivity between the right superior parietal lobule and the middle frontal gyrus. The magnitude of green tea induced an increase in parieto-frontal connectivity that translated into task performance improvement (6). Therefore, it is assumed that green tea extract might be beneficial for the treatment of disorders such as dementia.

Concentration and reduced response time

Two constituents – caffeine and L-theanine –  both present in matcha in perfect proportions, positively affect our cognitive performance. In 2017, some Dutch researchers assessed how the consumption of matcha and matcha-containing products influences our cognitive functions. Each participant had to consume one of the four test products: matcha tea, matcha tea bar (4 g matcha tea powder per item), placebo tea, or placebo bar. Then the participants performed a set of cognitive tests to assess their attention, data processing abilities, working memory, and episodic memory, by which we mean a person’s unique recall of a specific event. Research findings revealed that drinking matcha  improved basic attention abilities and psychomotor speed in response to stimuli (7).

 

SCIENTIFIC RESEARCH ON EGCG CATECHINS

 

Catechins belong to the group of polyphenols. They are present in many dietary products: plants, fruits (e.g. apples, blueberries, gooseberries, grape seeds, kiwi, strawberries), red wine, beer, cacao liquor, chocolate, cocoa, plain green tea; but matcha is their richest source. Catheins fight bacteria, fungus and viruses. Therefore, they strengthen the immune system. They also remove heavy metals from the body and slow down the aging process. Tea catechins and polyphenols are effective scavengers of reactive oxygen species. Findings of the most recent studies demonstrate the connection between drinking green tea on a regular basis and the delay of tumor growth.

Some American scientists from the University of Colorado compared the concentration of EGCG in an infusion of the high quality Japanese matcha and that of the bag of Starbuck’s green tea. Findings indicate that the concentration of epigallocatechin gallate (EGCG)  in matcha was 137 times higher than in a bagged tea. Even high quality green tea contains three times less EGCG catheins than matcha (8).

Catheins EGCG = Antioxidants that inhibit the aging process

Catheins are polyphenols that work as powerful antioxidants. They eliminate reactive oxygen species, including free radicals and peroxides. This is why matcha tea has a superoxidant effect that counteracts the abnormal activity of reactive oxygen species. The concentration of reactive oxygen species in cells is regulated by antioxidants, including free radical scavengers, glutathione, tocopherols and antioxidant enzymes. The imbalance between the oxidants and antioxidants causes an oxidative stress that may lead to cell damage or cell death High oxidative stress, with its damaging effect to the tissues, may probably cause neurodegenerative diseases like Parkinson or Alzheimer. It is also related to the occurrence of coronary artery disease.

Weight-loss effect

Matcha tea helps to burn the excess of calories and reduces blood glucose and insulin levels, even if we do not change our eating habits. The meta-analysis of the research findings published in the American Journal of Clinical Nutrition demonstrates that regular green tea consumption results in burning 100 extra calories daily (10). This is because the EGCG catechins increase energy expenditure and speed up fat burning. Other study showed that green tea consumers lost, on average, 1.3 kg during the twelve-week experiment, without changing their eating habits. According to another research, people drinking green tea on a regular basis have, on average, lower BMI and smaller waist circumference than non-users. Waist circumference is an important determinant of our state of health. Too much fat in there indicates metabolic abnormalities such as hypertension, hypercholesterolemia and diabetes.

A research conducted by the Sao Paolo University on a group of obese women demonstrated that enriching weight-loss programs with green tea brings the best results. Women who, apart from following the diet and continuing the workout, were drinking green tea for eight weeks, not only lost, on average, 5.8 kg but also decreased in waist circumference. Furthermore, they reduced the level of triglycerides and increased lean body mass and muscle strength (11). Scientists from the Penn State University made similar findings concerning catechins in green tea (12). It follows from a research conducted by The Royal Society of Chemistry that the effects of consuming regular green tea are multiplied when it comes to matcha. That is because whenever we drink a bowl of matcha we consume the whole powdered leaves, and therefore we assimilate a lot more nutrients and benefits than from a regular tea (both soluble and insoluble ingredients). The same experiment, although performed on mice, confirmed that matcha effectively lowers the level of low-density lipoprotein-cholesterol (LDL-C).

 

BIBLIOGRAPHY:

1. „Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis”, Nutrition Reviews. 2014 Aug;72(8):507-22, https://www.ncbi.nlm.nih.gov/pubmed/24946991
2. “The effects of L-theanine on alpha-band oscillatory brain activity during a visuo-spatial attention task” Brain Topogr. 2009 Jun;22(1):44-51, https://www.ncbi.nlm.nih.gov/pubmed/18841456
3. 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 Jul;232(14):2563-76, https://www.ncbi.nlm.nih.gov/pubmed/25761837
4. “Acute effects of tea consumption on attention and mood”, The American Journal of Clinical Nutrition, Volume 98, Issue 6, 1 December 2013, http://ajcn.nutrition.org/content/early/2013/10/30/ajcn.113.058248.abstract
5. Green tea effects on cognition, mood and human brain function: A systematic review”, Phytomedicine. 2017 Oct 15;34:26-37, https://www.ncbi.nlm.nih.gov/pubmed/28899506
6. “Green tea extract enhances parieto-frontal connectivity during working memory processing”, Psychopharmacology (Berl). 2014 Oct;231(19):3879-88, https://www.ncbi.nlm.nih.gov/pubmed/24643507
7. “An intervention study on the effect of matcha tea, in drink and snack bar formats, on mood and cognitive performance”, Food Research Int. 2017 Sep;99(Pt 1):72-83, https://www.ncbi.nlm.nih.gov/pubmed/28784536
8. “Determination of catechins in matcha green tea by micellar electrokinetic chromatography”, Journal of Chromatography A. 2003 Sep 5;1011(1-2):173-80, https://www.ncbi.nlm.nih.gov/pubmed/14518774
9. „The Powdering Process with a Set of Ceramic Mills for Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect”, “Molecules” 2016, 21(4), 474; http://www.mdpi.com/1420-3049/21/4/474
10. “Catechin- and caffeine-rich teas for control of body weight in humans”, The American Journal of Clinical Nutrition, Volume 98, Issue 6, 1 December 2013, https://academic.oup.com/ajcn/article/98/6/1682S/4577486
11. “The Effects of Green Tea Consumption and Resistance Training on Body Composition and Resting Metabolic Rate in Overweight or Obese Women”, Journal of Medicinal FoodVol. 16, No. 2, https://www.ncbi.nlm.nih.gov/pubmed/23140132
12. “Epigallocatechin-3-gallate Increases the Expression of Genes Related to Fat Oxidation in the Skeletal Muscle of High Fat-Fed Mice.” “Food & Function” 2011,