Satisfy your thirst with a cup of tea. Contrary to popular belief, the brew is not dehydrating. Research published in the European Journal of Clinical Nutrition reports that tea rehydrates the body as well as water — and is more nutritious. Tea contains fluoride, which helps promote strong, healthy teeth. Plus, research from the Netherlands suggests that drinking three to six cups of black tea a day is linked to a significantly lower risk of death from heart disease when compared to drinking less than one cup per day. In other studies, green tea appears to have some heart-protective benefits.