Green tea

The use of green tea (GT) by Asian tribes predates written history. Early in recorded history, the use of GT became enshrined in Asian culture, religion, and traditional medicine. GT is different from black tea because, immediately after plucking, heat treatment of the leaves preserves the catechins and other phytochemicals from biodegradation. The most common use of GT is a water infusion known as a cup of tea. GT extracts concentrate the phytochemicals in GT and the phytochemical composition is determined by the content in the plant material and the method of manufacturing. After ingestion, the phytochemicals are absorbed and have pharmacological effects. GT and its extracts ameliorate, especially with exercise and dietary change, the pathophysiology of chronic inflammatory syndrome inclusive of weight loss, reduced insulin resistance, and reduced risk of cardiovascular disease. There is evidence that the consumption of GT reduces the risk of breast, prostate, and colorectal cancers and also reduces their risk of reoccurrence. GT is considered to have a positive effect on the colonic microbiome. Sinecatechins, manufactured from GT, are approved as a treatment for genital warts. GT extracts, especially at higher doses, can be toxic to the liver. GT extracts can interfere with iron and folic acid absorption, and can alter the pharmacology of prescription drugs.