Compilation by Armando Gonzalez Stuart, PhD.
Other Common Name:
Parts of the plant used:
The young, unfermented leaves.
How is it used?
The beverage made by steeping the leaves of this plant in hot water, is the most popular method of ingestion. Capsules containing pulverized leaves, sometimes combined with other herbs, are also available. Extracts with measured quantities of polyphenols (antioxidant compounds) are likewise found on the market.
What is it used for?
Green tea contains compounds known as antioxidants, which help neutralize free radicals. Free radicals may sometimes exert harmful effects upon cells and are said to be involved in the initiation of certain types of cancers. The compounds known as polyphenols belong to this group of plant antioxidants, and have been shown to inhibit human carcinogens of diverse origin in laboratory studies. Research in animals fed green tea seems to confirm this, although not all studies have shown the same effects. It is thought that this herb’s antioxidant effect could be of use as a preventive to some types of cancers, namely prostate, ovarian, breast and colon cancer, although the mechanism by which it would exert this effect is only partially understood at this time. Much more research in humans is needed in order to confirm all of green tea’s potential benefits as a cancer preventive. This herb has diuretic properties, encouraging urination. It has also been used in China as a tonic for people with weak hearts. Some herbal products used for weight loss contain green tea, purportedly because it increases “thermogenesis”, or an increase in temperature that is supposed to break down fat in the body. Since green tea contains caffeine, it is also ingested as a mild stimulant to combat fatigue. This herb should not be consumed in large quantities before bedtime in people who have trouble getting to sleep. Green tea may be of help in reducing cholesterol levels, as well as risk for heart attacks, but more research needs to be done in this area.
Safety / Precautions
- Avoid large amounts during pregnancy and lactation.
- Do not give green tea to infants, since it may interfere with iron metabolism and cause anemia.
- People with liver, kidney or heart disease should consult with their physician before taking large amounts of the tea, or products made from it.
- Avoid taking this herb with others that have central nervous system stimulating effects such as coffee, guaraná, ephedra (ma huang) or máte, for example.
- People suffering from insomnia should not ingest large amounts of green or black tea, especially at night.
Before you decide to take any medicinal herb or herbal supplement, be sure to consult with your health care professional first. Avoid self-medication and self-diagnosis: Always be on the safe side!