Green Tea (Camellia sinensis)

 

The tea plant has been cultivated in China for thousands of years. It is an evergreen or tree that can grow 30 feet in height. The part used is the leaf bud and the two adjacent young leaves. Green tea is produced by lightly steaming the fresh cut leaf before it is allowed to dry and therefore oxidize. Green tea is very high in polyphenols (catechin, epicatechin, epicatechin gallate, epigallocatechin gallate, and proanthocyanidins.) Epigallocatechin gallate is the most significant active component. One cup of green tea contains about 300-400 mg of polyphenols and 50-100 mg of caffeine.

 

Green tea polyphenols are potent antioxidant compounds that have demonstrated greater antioxidant protection than Vitamin C and E. In addition to exerting its own antioxidant activity, it increases the activity of antioxidant and detoxifying enzymes such as glutathione peroxidase found in the liver, small intestine and lungs.

 

In animal studies and in vitro, green tea inhibits cancer by: blocking cancer causing agents such as nitrosamines; blocking the interaction of tumor promoters, hormones, and growth factors; and preventing cancer such as stomach, small intestine, pancreas, colon, lung and estrogen related cancers including most breast cancers.

 

Green tea consumption with meals may inhibit the formation of nitrosamines, which are formed when nitrates such as those found in cured meats, bind to amino acids. The polyphenols of green tea strongly inhibit this process and may account for the lower cancer rate in Japan, where it is customary to drink green tea with each meal.

 

The normal dosage consumed by Japanese and other green tea drinking cultures is about 3 cups per day, or 300-400 mg of polyphenols with 55 percent epigallocatechin.

 

There is no toxicity associated with green tea, but as in any caffeinated beverage, over consumption may produce a stimulatory effect such as nervousness, anxiety, insomnia, and irritability. For most people however, even those sensitive to caffeine, these effects are rarely seen.

 

Dr. Pincott has been practicing naturopathic medicine since 1985 and is currently practicing in Campbell River. She can be reached at (250) 286-3655 or www.DrPincott.com