Tea was probably used first in China, since there are accounts from visitors to that land in 850 A.D. describing the use of a medicinal beverage named "Chah" or "Fah." In Europe the use of tea as a beverage dates from the 17th century. The importance of this item in the diet can be gained from the fact that the annual consumption of tea in the United States now amounts to about 98,000,-000 pounds per year.1 In spite of the widespread use of this beverage, information regarding its physiological activity is limited. Psychological testing has shown that a cup of tea affords an immediate as well as a delayed lift without inducing secondary depressing effects.2 This study was undertaken to investigate by objective methods the effects of tea on digestion and on various associated physiological processes.
In addition to caffeine and tannin, tea contains a variety of substances
Wirts CW, Rehfuss ME, Snape WJ, Swenson PC. EFFECT OF TEA ON GASTRIC SECRETIONS AND MOTILITY. JAMA. 1954;155(8):725–729. doi:10.1001/jama.1954.03690260017005