Tea contains catechins, a type of antioxidant. In a fresh tea leaf, catechins can be up to 30% of the dry weight. Catechins are highest in concentration in white and green teas, while black tea has substantially fewer due to its oxidative preparation. Tea contains theanine, and the stimulant caffeine at about 3% of its dry weight, translating to between 30 mg and 90 mg per 8 oz (250 ml) cup depending on type, brand[13] and brewing method.[14] Tea also contains small amounts of theobromine and theophylline.[15] Tea also contains fluoride, with certain types of brick tea made from old leaves and stems having the highest levels.[16]
Tea has almost no carbohydrates, fat, or protein.
