What to Look for in Green Tea Extract

Originating in China, the tea plant, scientifically known as Camellia sinensis, has been used for thousands of years for its stimulant and healing effects. Oolong and black teas are made from the same plant as green tea, the difference consisting in the oxidation process, which is complete in the case of black tea, partial for oolong tea and stopped by steaming the fresh-cut leaves in order to make green tea. This different processing makes the green tea anti-oxidant factor six times greater than for black tea.

Forms

Green tea can be found on the market in the form of capsules, powder and liquid extracts or tea bags for infusion.

Compounds

The most important component of green tea is the polyphenols, which are responsible for its anti-oxidant properties, as well as for the slightly bitter taste. Green tea also contains alkaloids like caffeine (also called theine or teine), theobromine and theophylline, which contribute to its energizing effect. Over 300 volatile compounds give tea its particular aroma.

Dosage

A typical daily dosage to look for in a green tea extract is 240 to 320 mg of polyphenols, the amount contained in two to three cups of tea, according to the University of Maryland Medical Center website.

Health Effects

The curative effects of green tea have been observed primarily in the fields of cancer prevention and heart disease, according to the PDR for Herbal Medicines (Physician's Desk Reference for Herbal Medicines), 2004 . Clinical studies have provided evidence for its efficiency in the prevention and even treatment of cancers that affect the pancreas, colon, small intestine, stomach, breast and lungs, according to the UCLA Jonsson Comprehensive Cancer Center website.

Green tea has also been shown to reduce cholesterol, inhibit the development of atherosclerosis and consequently reduce the risk of coronary heart disease. Its anti-inflammatory, anti-oxidant, hepato-protective, anti-viral and anti-bacterial properties have been shown to be efficient in the treatment of inflammatory diseases, diarrhea, liver disease, gout, diabetes and obesity, dental plaque and carries.

Uses

Green tea extract is used by multiple alternative therapy methods. In Chinese medicine, it is considered to treat migraine, nausea, diarrhea and other digestive problems. Homeopathy recommends a homeopathic dilution for circulatory conditions, headaches, depression, agitation and stomach pains. Indian Ayurvedic medicine uses green tea for the treatment of diarrhea, loss of appetite, migraine, cardiac pain, fever and fatigue.

Precautions

Pregnant and breastfeeding women are advised to reduce their consumption of green tea due to its caffeine content. It is also not recommended for people with stomach sensitivity, cardiovascular problems, hyperthyroid or renal disease. Long-term use in large quantities may cause irritability, palpitations, vertigo, sleeplessness, diarrhea, appetite loss and headaches.

Drug Interactions

Absorption of alkaline medication can be delayed by chemical bonding with the tannins in green tea.