Green tea is derived from the leave of a plant called camellia sinensis. The leaves are processed and used to make tea.
Green, black and oolong teas are all sourced from camellia sinensis. The differences in processing determine which kind of tea the leaves become.
1. Cancer Prevention: The majority of research to date on Green tea focuses on cancer prevention. Population studies in Asia have found lower rates of cancer among those who consume large amounts of Green tea. (10) a Study of Japanese men and women with a 13 year follow up revealed that increased consumption of Green tea was associated with a delay of diagnosis of cancer.(1) Mean age at cancer onset among men and women who consumed over 10 cups of Green tea a day was 7.6 years later than those consuming less than three cups. It was noted that the delay in cancer was only relevant to those below the age of 79. Animal, human and test tube studies have shown that Green tea may reduce the risk of prostate, breast, esophageal, lung, skin, pancreatic and bladder cancers.(2) Of the hundreds of studies done on Green tea, only about 10% have involved humans.(10) While the data is promising, it is still limited. The good news is that this data is providing insight and direction for further studies to be done on the chemopreventive effects of Green tea.
2. Protecting the heart: There is early evidence, though not conclusive, that regular intake of Green tea may reduce the risk of cardiovascular disease. Several well designed studies have demonstrated significant risk reduction in people who drink Green tea regularly.
Coronary Heart Disease - A recent cohort study assessed the effects of Green tea on 8,522 Japanese men over a period of 12 years. The data showed that men who drank 10 cups of Green tea daily versus the men who consumed only three cups daily have a lower risk of death from coronary heart disease. (3)
Stroke - A cohort study of Japanese women demonstrated an inverse relationship between Green tea consumption and the incidence of stroke. The study followed 5,910 Japanese women who neither smoked nor drank alcohol for four years. The incidence of stroke was significantly lower in women who consumed at least three to four cups of Green tea per day. (3)(11)
Hypertension - In a study published in the archives of Internal Medicine, researchers concluded that consumption of Green or oolong tea at 10 ml or more per day, for one year, significantly reduced the risk of developing hypertension.(8) Researchers also examined the impact of long term tea consumption on the risk of developing hypertension in 1,507 men and women. Those who consistently drank 120 ml or more of tea per day had a lower risk of developing hypertension.
3. Exercise Endurance: People have long used Green tea for energy. A new study might shed light on Green tea as a tool for endurance. Published by American Physiological Society, the study demonstrated that Green tea extract markedly improved endurance capacity in mice.(5) Swimming time to exhaustion was evaluated in mice fed Green tea extract. The mice that were fed Green tea extract had prolonged endurance capacity by 8-24% and the effect was accompanied by a stimulation of lipid metabolism. It is also noted that the effects were dose dependent. Although not yet confirmed in human studies, these results suggest Green tea might be a useful tool for athletes.
4. Weight Loss: The newest research on Green tea has been in the area of weight loss. Research suggests Green tea promotes weight loss by favorably affecting lipid metabolism in the blood, and through the stimulation of thermogenesis (Fat-Burning).(4)(12) Regarding Green tea and thermogenesis, a study examining the benefits of functional foods for weight control showed that Green tea increased energy expenditure over a 24-hour period. This is probably due to the combination of catechins and caffeine naturally occurring in Green tea.(4) Green tea extract looks to be a promising new tool for weight loss.
Article Source: http://vitanetonline.com