Green Tea

Camellia sinensis

Camellia assamica

Origins

• Southeast Asia

• 2737 B.C. First written record

• Emperor Shen Nong

• Homo erectus

Historic Uses

• Used historically in China for many different ailments

• Used as a currency

• 500 A.D. Demand rises, and farmers begin to cultivate tea

Tea Moves West

• 1606 First shipment of tea to Europe, by the Dutch East India Company

• 1657 Tea reaches general population of Europe

• Robert Fortune

• By 1850s England was consuming over 80 million pounds of tea annually

• Kenya, Cameroon, South Africa, India, Sri Lanka

Growing Camellia sinensis

• Shrublike and Grown in a Semi Tropical Environment on Plantations in Southeast Asia– Heavy rainfall, 3000-7000 ft. elevation

• Cloning or Grown from Seed– Cuttings obtained from mother bush– Rooted and grown in nursery for 1 or 2 years

• Grown in Rows or on Terraces– 4 feet apart and 4-5 feet tall– Help irrigation and prevent soil erosion

How Green Tea is Made

• Leaves are usually picked by hand• Leaves are steamed, rolled, and dried

immediately and completely– Not fermented like black teas

• Packed in foil-lined chests– Prevent absorption of unpleasant odors– Prevent loss of aroma

• Serve warm, but not hot, to keep medicinal value intact

Active Compounds

• The active compounds in green tea are from a group of polyphenols called catechins

• Four catechins present in green tea:

• Epicatechingallate

• Epicatechin• epigallocatechin

• Epigallocatechingallate

Active Compounds

Mode of Action

• Antioxidant• With HIV the epigallocatechingallate acts as a

block to the HIV transport protein on the host cell• In cases of Dementia the epigallocatechingallate

stops the formation of plaque and tangles by inducing the PKC pathway which increases the levels of α-secretase an enzyme the inhibits Aβ proteins a precursor to neurofibular tangles associated with Alzheimer's

Mode of Action

• Cancer• Epigallocatechingallate has been shown to inhibit

angiogenesis of tumor cell and thus not allowing them to become cancerous. This is achieved by stopping the production of angiogenic compounds in the tumor cells.

• It has also been suggested that green tea may induce apoptosis in cancer cells by shutting down the NF-KB pathway.

Mode of Action

• Weight loss• Epigallocatechingallate prevents the breakdown of

norepinephrine thus causing a raise in metabolism. It may also Inhibit adipocyte hypertrophy and hyperplasia, and possibly inhibit gastrointestinal enzymes involved in nutrient uptake, the mechanisms have yet to be deciphered for these processes.

Green Tea use in Cancer Prevention

• Green Tea stops angiogenesis– Stops blood flow to tumor– Mice given green tea

• EGCG slowed angiogenesis

• Green Tea induced apoptosis– Increases normal cell growth while promoting

programmed cell death– Mice given green tea over a 4 month period

• tumors suppressed

Treating Alzheimer’s

• Green Tea is antioxidant– Mice (in vivo) had Aβ peptides formation

slowed– EGCG activated the protein kinase C pathway

, which stops Alzheimer’s

Weight Loss

• Healthy Human Males– 3 Groups: EGCG+caffeine, caffeine only, and

placebo• EGCG group burned more fat than any other group

– Human Study• 3 Month Period of people drinking Green Tea

– Catechins causes more weight loss by causing the subjects to increase energy

Current Studies:Body Fat and LDL reduction

• Two groups of men with similar BMI and waist circumference underwent 12 wk study. One group ingested a bottle of tea containing 690mg catechins, the second group received only 22 mg catechins.

• Average weight loss in group 1 was 2.4 kg. In the second group it was only 1.3 kg.

• LDL levels of group 1 decreased by about 11.5%; in group 2, only by about 5.2%.

Current Studies:Alcohol and Hepatic Toxicity

• 3 groups of rats were administered ethanol. Two of the groups were also treated with theanine, one prior to ethanol, one after.

• Both theanine treated groups showed decreased blood alcohol concentration.

• LPO levels in the livers of the ethanol alone rats nearly doubled after 3 hours. The LPO levels of the theanine treated rats remained basically normal throughout the experiment.