Black tea is a fully fermented tea. It contains vitamins, caffeine, amino acids, minerals, polysaccharides, tea polyphenols, and more, which are known to help reduce blood sugar, lower blood pressure, and decrease blood lipids. Varieties of black tea include Keemun Black Tea, Darjeeling Black Tea, Ceylon High Altitude Black Tea, Assam Black Tea, Lapsang Souchong (Zheng Shan Xiao Zhong), Dianhong Gongfu Black Tea, and Jin Jun Mei Black Tea