Health effects of tea

The health effects of tea have been studied throughout human history. In clinical research conducted over the early 21st century, tea has been studied extensively for its potential to lower the risk of human diseases, but there is no good scientific evidence to support any therapeutic uses other than possibly increasing alertness, an effect caused by caffeine in the tea leaves.^[1][2]

A small number of studies suggests that both green and black tea might have beneficial effects on some cardiovascular disease risk factors, including blood pressure and cholesterol.^[1] The research has limitations though, including how the data were evaluated and differences in study populations, leading to no certain conclusions about health effects.^[1][2]

In regions without access to safe drinking water, boiling water to make tea is effective for reducing waterborne diseases by destroying pathogenic microorganisms.