What is Green Tea?
The tea plant, Camellia sinensis, originated in East Asia, and was first cultivated in China and India. The most common types of tea are green, black and oolong. All three types of tea come from the same tea plant, but differ in the way they are processed. Black tea leaves are processed the most, while green tea receives the least amount of processing, so that more of the beneficial components are retained. This is why green tea is considered to be healthier than black tea.
Green Tea Health Benefits
Green tea contains a class of antioxidant polyphenols called catechins that benefit health by helping to remove free radicals that can damage cells and cause diseases. There are six different catechin compounds in green tea. The most active catechin is epigallocatechin-3-gallate (EGCG).
The following are some of the ways in which green tea can benefit health:
Lowers cholesterol- green tea lowers total cholesterol and LDL (bad) cholesterol levels, while raising HDL (good) cholesterol. According to animal studies, the polyphenols in green tea may inhibit cholesterol from being absorbed by the intestines and increase its excretion from the body.
Lowers risk of heart disease- the cholesterol-lowering properties of green tea help to prevent atherosclerosis and coronary artery disease
Lowers risk of cancer- in numerous studies, green tea has been shown to reduce the risk or improve the survival rate for many different types of cancer, including colorectal, esophageal, lung, pancreatic and prostate. In a study involving women with Stage I and II breast cancer, drinking green tea reduced the rate of the cancer recurring. Green tea also significantly improved survival rates of those with bladder cancer.
Alleviates symptoms of diabetes- green tea helps to regulate blood sugar levels, and it may prevent type 1 diabetes. Some clinical studies showed that green tea extract decreased hemoglobin A1c levels in borderline diabetes patients.
Protects against liver damage- green tea helps to protect the liver from damage by toxins such as alcohol. In animal studies, green tea protected against the growth of liver tumors.
Protects against symptoms of inflammatory bowel disease- green tea’s anti-inflammatory properties benefit those with Crohn’s disease and ulcerative colitis.
Promotes weight loss- green tea aids in losing weight by increasing the body’s metabolic rate and helping to burn fat.
The amount of polyphenol antioxidants contained in a cup of green tea varies depending on the brand. To obtain health benefits, it is recommended to drink 2-3 cups of green tea daily, which will provide 240 – 320 mg of polyphenols. For those who want to avoid caffeine, decaffeinated green tea is available. Green tea is also available as capsules and as a standardized extract. Taking 170-750 mgs of green tea extract per day is the recommended dosage.
Cautions and Contraindications
Green tea is generally safe, but it should be avoided by those who are taking blood thinning medications such as warfarin and aspirin, and also by those who are taking certain antipsychotic drugs, MAOI antidepressants, or those who are receiving chemotherapy.
This information is for educational purposes only. If you have a health concern, see a qualified health care provider.
Sources:
http://www.umm.edu/altmed/articles/green-tea-000255.htm
http://www.whfoods.com/genpage.php?tname=foodspice&dbid=146
