It depends on the type of tea you use. Bottled or canned iced tea and iced tea made from powdered mixes or herbal teas don't provide the same benefits that iced black or green teas seem to offer. Research on tea's health benefits focuses on flavonoids, the antioxidants naturally found in black and green teas. Flavonoids may help protect body cells by fighting free radicals-harmful compounds that may damage cells and in turn, potentially increase risk for heart disease, cancer and inflammation.
An 8-ounce glass of unsweetened iced tea has 0 calories, but a glass of "sweet tea" may contain 30 to 90 calories, depending on how much sugar is added. Spice up the flavor of iced tea without extra calories by choosing fruit-flavored black or green teas, floating fresh mint leaves or orange and lemon slices in the pitcher, or brewing tea with ginger or cloves.