Health Benefits

Japanese green tea contains a number of beneficial nutrients, and many scientific studies support its positive impact on health. Of the nutrients present in green tea, the ones most strongly correlated with health benefits are the catechins, a group of potent antioxidants. Of these, EGCG (epigallocatechin gallate) has been determined to have the most positive effects.

 

EGCG, alone and in combination with caffeine also present in tea, has been shown to reduce occurrences of many life-style related diseases. While not an exhaustive list, research supports that EGCG helps by:

-Improving cardiovascular circulation

-Lowering blood sugar

-Increasing metabolism

-Lowering LDL levels (low-density lipoprotein, or “bad” cholesterol)

-Fighting cavity-causing bacteria

 

Water-soluble nutrients in leaves (20-30%)

Component % by Weight Bioactivity
Catechins 11-17 % Anti-oxidant, Anti-mutagen, Anti-carcinogenic, Anti-metastastic, Anti-hypertensive, Lowers LDL levels, Lowers blood pressure, Lowers blood sugar, Reduces clotting, Anti-bacterial, Anti-carious, Anti-allergen, Deodorant
Caffeine 1.6-3.5 % Central nervous system stimulant, Cardiac stimulant, Diuretic, Metabolic stimulant
Theanine 0.6-2.0 % Neuromodulator, Boost cognitive performance, Stress reduction, Relaxing effect, Caffeine-absorption inhibitor
Flavonols 0.6 % Reinforces capillary resistibility, Anti-oxidant, Anti-carcinogenic, Deodorant
Complex Polysaccharides 0.6 % Lower blood sugar levels
Vitamin C(Ascorbic Acid) 0.3-0.5 % Anti-oxidant, Anti-carcinogenic, Immune system enhancer, Cold prevention, Anti-scurvy, Cataract prevention
γ-amino acid (GABA) 0.01% Lowers blood pressure, Neuromodulator
Saponin 0.2 % Anti-asthmatic, Anti-bacterial, Lowers blood pressure
Vitamin B₂ 1.2 % Skin health, Anti-oxidant
Dietary Fiber 3-7 % Improves digestion, Lowers blood sugar
Minerals 1.0-1.5 % Zinc: Strengthens immune system, Promotes skin health; Fluorine: Strengthens teeth; Manganese, Copper, Zinc, Selenium: Antioxidants

Insoluble nutrients in leaves (70-80%)

Component % by Weight Bioactivity
Dietary Fiber 30-44 % Improves digestion, Lowers blood sugar
Proteins 24-31 % Energy source, body repair
Fats 3.4-4.0 % Energy source, Cell-wall component
Chlorophyll 0.6-1.0 % Deodorant
Vitamin E 0.02-0.07 % Anti-oxidant, Anti-carcinogenic, Improves blood circulation, Reduces clotting, Immune system enhancer
Coenzyme Q-10 0.01 % Anti-aging, Skin health, Migraine relief
β-carotene 0.02 % Anti-oxidant, Anti-carcinogenic, Immune system enhancer, Vitamin A production
Minerals 4-5 % (Manganese, Copper, Zinc, Selenium) Necessary for bones and nervous system function
Flavor Component 1-2 mg% Aromatic effect

Sources:

Keiichiro Muramatsu “Function of Tea” Japan Scientific Societies Press, March 2002

Nihoncha (Japanese Tea) Instructor Text Book 2, p75, May 2007, Nihoncha Instructor Association