Health studies on tea
First, a little intro to bring the reader up-to-speed on tea. Tea comes from steeping parts of Camellia sinensis in hot or boiled water. Depending on the level of oxidation of the tea leaves, you get different types of tea: white, oolong, green, and black tea. Herbal teas are made in the same way, but not using the Camellia sinensis plant. So, a “true” tea is any tea made from Camellia sinensis. A lot of health studies focus on green tea (common healthier tea), and some on black tea (most common tea). But just to be clear, green tea is real tea.
“Coffee and tea: perks for health and longevity?” 2013. pubmed
Tea consumption, especially green tea, is associated with significantly reduced risks for stroke, diabetes and depression, and improved levels of glucose, cholesterol, abdominal obesity and blood pressure… However, caffeine at high doses can increase anxiety, insomnia, calcium loss and possibly the risk of fractures…tea can generally be recommended as health-promoting additions to an adult diet…