Benefits: Green Tea
2018-06-01 17:43:26 - Tea Benefits
Green tea is made from un-oxidized leaves and is one of the less processed types of tea (with white tea the least) and therefore contains one of the most antioxidants and beneficial polyphenols.
Green tea was used in traditional Chinese and Indian medicine to control bleeding and heal wounds, aid digestion, improve heart and mental health and regulate body temperature.
Recent studies have shown green tea can potentially have positive effects on everything from weight loss to liver disorders to type 2 diabetes.
Possible health benefits of green tea
Listed below are the possible health benefits associated with green tea:
According to the National Cancer Institute, the polyphenols in tea have been shown to decrease tumor growth in laboratory and animal studies and may protect against damage caused by ultraviolet UVB radiation.
In countries where green tea consumption is high cancer rates tend to be lower, but it is impossible to know for sure whether it is the green tea that prevents cancer in these specific populations or other lifestyle factors.4
One large-scale clinical study compared green tea drinkers with non-drinkers and found that those who drank the most tea were less likely to develop pancreatic cancer, particularly women, who were 50% less likely to develop the disease.
Studies have also shown the positive impacts of green tea on breast, bladder, ovarian, colorectal, esophageal, lung, prostate, skin and stomach cancer.
Researchers believe that it is the high level of polyphenols in tea that help kill cancerous cells and stop them from growing, however the exact mechanisms by which tea interacts with cancerous cells is unknown.
Other studies have shown a lack of preventative effects of tea on cancer. The amount of tea required for cancer-preventive effects has also varied widely in studies – from 2- 10 cups per day.
In 2005, the FDA stated that “there is no credible evidence to support qualified health claims for green tea consumption and a reduced risk of gastric, lung, colon/rectal, esophageal, pancreatic, ovarian, and combined cancers.”
Similarly, in the Shanghai Men’s Health Study, green tea drinking was found to reduce the risk of colorectal cancer among nonsmoking men, but not in men in general.
In a recent large-scale, population-based case–control study in urban Shanghai, regular green tea drinking was associated with a 32% reduction of pancreatic cancer risk (compared to those who did not drink tea regularly) in women who were mostly nonsmokers.
Such a beneficial effect of tea drinking, however, was not observed in men who were mostly smokers and former smokers; however, among men who never smoked, a trend of decreased risk was observed.
Similarly, a recent systematic review of epidemiological studies in Japan on green tea consumption and gastric cancer indicated no overall preventive effect of green tea in cohort studies; however, a small consistent risk reduction was found in women (but not in males because many men were smokers). When the results of all six studies were combined, there was a significant protective effect of tea drinking against stomach cancer in women who did not smoke cigarettes or drink alcohol.
These studies demonstrated that the cancer-preventive activities of tea constituents can be manifested in humans.
A 2006 study published in the Journal of the American Medical Association concluded that green tea consumption is associated with reduced mortality due to all causes, including cardiovascular disease.
The study followed over 40,000 Japanese participants between the ages of 40 and 79 for 11 years, starting in 1994.
The participants who drank at least 5 cups of green tea per day had a significantly lower risk of dying (especially from cardiovascular disease) than those who drank less than one cup of tea per day.
Another study found that consuming 10 cups of green tea per day can lower total cholesterol, however, consuming 4 cups or less had no effect on cholesterol levels.1
Type 2 Diabetes
Studies concerning the relationship between green tea and diabetes have been inconsistent. Some have shown a lower risk of developing type 2 diabetes for green tea drinkers than for those who consumed no tea, while other studies have found no association between tea consumption and diabetes at all.1
Green tea may promote a small, non-significant weight loss in overweight and obese adults; however, since the weight lost in the studies were so minimal, it is unlikely that green tea is clinically important for weight loss.
Other studies have found that green tea is helpful in preventing dental cavities, stress, chronic fatigue, treating skin conditions and improving arthritis by reducing inflammation.