To sum up, here are just a few medical conditions in which drinking green tea is reputed to be helpful:
- rheumatoid arthritis
- high cholesterol levels
- cariovascular disease
- impaired immune function
Green tea is the best food source of a group called catechins. In test tubes, catechins are more powerful than vitamins C and E in halting oxidative damage to cells and appear to have other disease-fighting properties. Studies have found an association between consuming green tea and a reduced risk for several cancers, including, skin, breast, lung, colon, esophageal, and bladder.
Additional benefits for regular consumers of green and black teas include a reduced risk for heart disease. The antioxidants in green, black, and oolong teas can help block the oxidation of LDL (bad) cholesterol, increase HDL (good) cholesterol and improve artery function. A Chinese study published recently in the Archives of Internal Medicine showed a 46%-65% reduction in hypertension risk in regular consumers of oolong or green tea, compared to non-consumers of tea.
From weight loss to cancer, there are many benefits to drinking green tea. Here are five health benefits of drinking green tea that have been proven in correlation studies:
Research at the Graduate School of Medicine in Kyoto, Japan confirmed that green tea polyphenols can protect a heart from oxidative stress, as well as maintain good left ventricular function after ischemic arrest (restriction in the heart’s blood supply) and reperfusion (tissue damage caused when the blood supply returns).
Green tea also protects the heart by preventing hypertension.
A human study, published in the January 2005 issue of the American Journal of Clinical Nutrition, confirms green tea’s ability to not only reduce body fat, but damage to LDL cholesterol as well. After 12 weeks of drinking just one bottle of green tea each day, 38 normal-to-overweight men in Tokyo had a significantly lower body weight, BMI, waist circumference, body fat mass and amount of subcutaneous fat compared to men given a bottle of oolong tea each day.
Green tea may protect against death from all causes, especially cardiovascular disease. Japanese scientists analyzed data from a National Cohort Study that began in 1994 and had over 40,000 participants, age 40 to 79, who initially were free of stroke, heart disease and cancer. People were followed for up to 11 years.
Compared with participants who consumed less than 1 cup of green tea per day, those drinking 5 or more cups a day had a significantly lower risk of death from all causes, especially lower risk of dying from cardiovascular disease and stroke. The findings might explain in part the reason why the Japanese live longer than people in any other country. However, there was no cancer prevention benefit of green tea.
Memory and learning
One of the important health benefits of regular green tea drinking is improved memory and learning ability. In Japan there was revealed that high green tea drinking maintains cognitive function. Also, green tea consumption may enhance learning and memory ability.
The main components of green tea that are thought to work on improving brain function are polyphenols, epigalochatechin-3-gallate (EGCG), a very strong antioxidant. The high use of oxygen during the metabolic processes leads to the generation of a large number of free radicals (highly reactive molecules). EGCG can penetrate the brain's blood barrier and is able to enact its antioxidative affects on the free radicals that cause damage in the brain.
Green tea has not been studied in children, so it is not recommended for pediatric use.
Depending on the brand, 2 - 3 cups of green tea per day (for a total of 240 - 320 mg polyphenols) or 100 - 750 mg per day of standardized green tea extract is recommended. Caffeine-free products are available and recommended.