Guide to Specialty Products

Green Tea

General Description

Green Tea is most commonly bought as leaves that is brewed and then consumed as a beverage. It is available in a pill form, powdered form and liquid supplement. It is also added to many cold beverages, weight loss supplements and meal replacement supplement powders. It is also a popular additive in cosmetics.

Green tea contains two chemical constituents called polyphenols and catechins, as well as an important substance called Epigallocatechin Gallate (EGCG). These substances help lower cholesterol and improve lipid metabolism to improve the assimilation of blood sugars and lower the risk of diabetes and obesity. These polyphenols and catechins also have potent anti-bacterial and anti-viral properties that help prevent the body from being susceptible to infection and disease.

Sources of the Supplement

Almost all green tea is grown in countries in Asia, but it is also cultivated in many countries in the South Pacific. Green tea comes in two major varieties: Chinese Green Tea and Japanese Green Tea

Green tea (ryokucha) is very common in Japan. It is more commonly known as "tea" (ocha) and "Japanese tea" (nihoncha). Types of tea are commonly graded depending on the quality and the parts of the plant used. The very best Japanese green tea is said to be that from the Uji region of Kyoto.

Chinese green tea comes in many different varieties including a powdered type called gunpowder that is granulated and also highly caffeinated.

Common Uses

Green tea has numerous health benefits including:

• Lowering cholesterol
• Reduces heart attacks
• Speeding weight loss
• Preventing skin damage
• Strengthening bones
• Preventing arthritis
• Healing lung damage
• Preventing cancer

Studies

Since the early 1990s, there have been many studies conducted on green tea assessing its effectiveness at healing a variety of conditions.

In a Japanese study conducted in 1991, 6,000 women, who drank over 5 cups of green tea per day cut their risk of strokes by 50 percent. In 1991, researchers from the National Defense Medical College in Saitama, Japan revealed that total serum cholesterol levels were lower in Japanese men who drank green tea.

Researchers at Beth Israel Deaconess Medical Center in Boston, Massachusetts performed a study to determine if green tea was able to extend the life of those who had suffered heart attacks. The test involved 1,900 individuals. It was found that those who drank 19 or more cups of green tea a week reduced their risk of dying over the following five years by 44%.

In a study about green tea and weight loss conducted by the University of Geneva, researchers concluded that people who drank one cup of green tea a day burned an additional 70 calories a day.

A study conducted at Case Western Reserve University in Cleveland, Ohio, found that drinking four cups of green tea a day could prevent sun damage to the skin.  This is probably due to the fact that exposure to ultraviolet rays causes free radicals and green tea fights harmful free radicals.

Researchers from National Cheng Kung University Hospital in Tainan discovered that green tea strengthens bones. This is because green tea contains fluoride and flavanoids, which are known nutrients that support the skeletal system. This study was based on 1,037 men and women, 30 and older. Each of the study subjects were questioned about tea consumption habits and then given a bone mineral density test. It was found that those who habitually consumed tea for more than ten years had a bone density that was 6.2% higher than those that did not.

Medical researchers at Case Western Reserve University in Cleveland reported in April 1999 that drinking four or more cups of green tea a day might prevent rheumatoid arthritis. The study was conducted on mice. It was found that arthritic mice that were given green tea to drink instead of water did not develop the disease as severely.

It also appears that green tea can help mitigate some of the damage that heavy cigarette smokers have done to their lungs. In two different studies, one by scientists at the Academy of Preventive Medicine in Beijing, China and the other by James Klaunig at the Indiana University School of Medicine in Indianapolis, the effects of green tea on the oxidative stress created by cigarette smoke toxins were examined. It was found that when cigarette users drank an equivalent of six cups of green tea a day, their bodies suffered 40% to 50% less oxidative damage. This means that green tea could potentially lower a smoker’s risk of cancer, emphysema, heart disease and other illnesses.

In 1998 a team of Chinese Scientists from the Institute of Nutrition and Food Hygiene discovered that drinking green tea improves pre-cancerous conditions of the mouth and the symptoms of oral cancer. After six months of drinking three cups of green tea a day, 38% of sufferers from oral cancer experienced a reduction in the size of a single lesion or in the number of multiple lesions that they experienced.

There is also evidence that drinking green tea can help inhibit tumor growth. In 2006 a research group from the Medical College of Ohio found that epigallocathechin -3 gallate (EGCG) acts as a good inhibitor of urokinase, an enzyme that causes tumors to grow.  Green tea has the potential to prevent cancer cells from growing new blood vessel networks that result in cancerous tissue masses.