Green tea is different than black and oolong teas because it is not fermented.  Black tea is fully fermented and oolong tea is partially fermented.  Green tea is produced by steaming fresh leaves at high temperatures. Green tea extract is produced by removing the water after the steaming process.  This process inactivates certain oxidizing enzymes, but doesn’t decrease polyphenols.  Polyphenols such as flavanols, flavandiols, flavonoids, and phenolic acids are abundant in green tea.  Flavanols, including epigallocatechin gallate (EGCG), are all referred to as catechins.  Another ingredient of green tea is the amino acid Theanine.   These seem to be responsible for the proposed benefits of green tea.(1)

First, let’s discuss Theanine.  The amino acid Theanine is related to glutamine, and can cross the blood-brain barrier. (meaning it can actually enter your brain circulation)  Because it can enter the brain, Theanine has been shown to reduce mental and physical stress.  It may produce feelings of relaxation and improves cognition and mood when combined with caffeine.(2)*  Theanine is speculated to produce these effects by increasing the levels of 3 neurotransmiters:  GABA, Serotonin, and Dopamine.(3)  Theanine also has been shown to boost the immune system.

EGCG in green tea extract has been show to improve cognitive performance and mental alertness, seems to lower cholesterol and triglycerides, especially LDL cholesterol, seems to prevent or delay the onset of Parkinson’s Disease and Alzheimer’s, and might protect against heart attack and stroke.(4-7)*  EGCG and other catechins in green tea might also reduce inflammation and protect cartilage by inhibiting collagen breakdown.(8) * This is an impressive list, but there are 2 other mechanisms that EGCG effects within our bodies that are so significant that they each will require a separate post.  First, there is evidence that EGCG might suppress appetite and can increase caloric expenditure and fat metabolism via the Leptin Pathway.*  Second, there is evidence that EGCG can significantly raise the levels of 3 of the 4 endogenous (meaning made inside the body) antioxidants:  Glutathione, SOD, and Catalase.*  This evidence comes from 2 well documented scientific studies and will be the topic of my next 2 post.  I hope you are beginning to see that Eiro Energy is truly a Health Promoting Beverage.

*  See Disclaimer Page

Resources:

1.  Nemecz G.  Green Tea.  US Pharm 2000;5:67-70.

2.  Haskell CF, Kennedy DO, Miln AL, et al. The effects of l-theanine, caffeine and their combination on cognition and mood. Biol Psychol 2007;77(2): 113-22.

3.  Nathan P, Lu K, Gray M, Oliver C.  The neuropharmacology of l-theanine: a possible neuroprotective and cognitive enhancing agent.  J Herb Pharmacother 2006;6(2):21-30.

4.  Mukamal KJ, Maclure M, Muller JE, et al. Tea consumption and mortality after acute myocardial infarction.  Circulation 2002;105:2476-81.

5.  Maron DJ, Lu GP, Cai NS, et al.  Cholestrol-lowering effect of a theaflavin enriched green tea extract: a randomized controlled trial.  Arch Inter Med 2003;163:1448-53.

6.  Ross, GW, Abbott RD, Petrovitch H, et al.  Association of coffee and caffeine intake with the risk of parkinson disease.  JAMA 2000;283:2647-9.

7.  Kuriyama S, Shimazu T, Ohmori K, et al.  Green tea consumption and mortality due to cardiovascular disease, cancer, and all-cause mortality.  JAMA 2006;296:1255-65.

8.  Haqqi TM, Anthony DD, Gupta S, et al.  Prevention of collagen-induced arthritis in mice by a polyphenolic fraction from green tea.  Proc Natl Acad Sci U S A 1996;96:4524-9.