Black Tea, Green Tea - Research
Studies on black or green tea leaf have demonstrated that they may have positive effects in the areas of cardiovascular health, osteoporosis, obesity, and bowel conditions.4 Green tea contains antioxidants, which have been shown to inhibit cardiovascular disease development and inflammation.6 Tea may also have psychological and neurological effects, such as increases in alertness and information processing, that are not due to caffeine but a chemical (theanine) in the tea leaves.7
Tea is used extensively in the traditional medicine systems of China, Hong Kong, Japan, and Korea.4 In China, the use of tea as a beverage dates back to 2700 BCE.4 Next to water, tea is the most widely consumed beverage in the world. The Chinese have a ritual tea drinking ceremony which started during the Sung Dynasty.
Traditionally, tea was rarely used as a medicine except as a stimulant, astringent (drying agent), and in infusions (teas) to relieve headaches.5
4 Blumenthal M, Hall T, Goldberg A, Kunz T, Dinda K, Brinckmann J, et al, editors. The ABC Clinical Guide to Herbs. Austin, TX: American Botanical Council; 2003.
5 Grieve M. A Modern Herbal. Vol II. New York: Dover Publications; 1971.
6 Henson S. Green tea and cancer care. HerbClip. June 15, 2004 (No. 020141-258) Austin, TX: American Botanical Council. Green tea catechins and L-theanine in integrative cancer care by Huber L. Alternative and Complementary Therapies. December 2003:294-298.
7 The health benefits of tea. HerbalGram. 1996; No. 37:38.