Aside from water is the most consumed beverage in the world.
Generally consumed in oolong, green and black tea forms originating from the leaves of Camellia sinensis plant.
Green tea in animal studies decreased cardiovascular disease and malignancies.
In a Japanese study there was an inverse relationship between green tea consumption and mortality due to all cause disease and due to cardiovascular disease.
An inverse association between consumption of tea and risk of incident diabetes mellitus exists, and individuals who consume more than 3 to 4 cups of tea per day have a 1/5 lower risk of subsequent diabetes, than non-coffee drinkers (Huxley R).
Tea catechins inhibit carbohydrate digestive enzymes which may decrease glucose production in the gastrointestinal system resulting in lower levels of glucose and insulin (Kobayashi Y).
Black, green and oolong tea increase insulin sensitivity by increasing insulin stimulated glucose uptake in adipocytes(Kato M).
Green and black tea are endowed with polyphenols act as a suppressor of the bacterias that cause dental plaque.
Green and black tea helps to sustain oral health and is advisable during or after a meal.
Green tea may prevent damage to pancreatic beta cells.
Regular tea drinkers have slow progression of coronary calcium and fewer cardiovascular events.
An association between higher intake of green tea and lower risk of death from all causes as well as a 31% reduction in risk of death from heart disease for those women drinking 5 or more cups of green tea per day.
Other studies indicate drinking green tea regularly for 20 years or more was associated with lower risk of digestive system cancers, while black tea has been linked with a lower risk of ovarian cancer.
Tea’s positive effects attributed to its high levels of antioxidants, polyphenols and flavonoids.
Metaanalyses: for each additional cup (8 ounces) of green or black tea was associated with a 2% lower risk of all-cause mortality, with stronger associations in those over the age of 65 years.
Others studies showed a 4% lower risk of CVD mortality for each additional cup of tea, and the effects were stronger in those over 65 years of age at 11%.
7 studies included in this analysis also showed a small, 2%, reduction in risk of heart attack or stroke for every additional cup of tea.