Tea is the most popular beverage in the world after water. It’s a simple preparation of pouring hot water over cured leaves of the Camellia sinensis plant. The first recording of tea described it as a medicinal beverage in China in the 3rd century AD. Merchants helped its popularity to spread quickly across continents. In the early 19th century, Great Britain popularized the concept of afternoon tea, a break from one’s routine in which tea is served alongside sandwiches and baked goods such as scones. The flavor of tea varies by where the tea leaves are harvested and how they are grown and processed. Black tea is the most popular worldwide, followed by green, oolong, and white tea. 
Herbal teas are not made from the Camellia plant but from dried herbs, spices, flowers, fruit, seeds, roots, or leaves of other plants; they do not typically contain caffeine as do traditional teas.
- Caffeine (traditional teas, not herbal)
- Flavonols – myricetin, quercetin, kaempferol
- Theaflavins – formed when black tea leaves are oxidized
- Catechins – found in green tea; epigallocatechin-3 gallate (EGCG) is the main form
Most traditional teas do not contain a significant amount of nutrients, but are rich in polyphenols. These are plant chemicals that give teas their distinct flavor and aroma and may have health-promoting properties.