First of all. tea is a great beverage, because it contains no sodium, fat, carbonation nor sugar. It is calorie free. It helps to provide proper hydration and fluid balance.
Tea contains flavonoids, which are antioxidants. Antioxidants counteract free radicals, which are believed to cause damage of body elements and contribute to chronic diseases.
Green tea is said to have the highest antioxidant levels out of all foods and beverages available to humans. There has been a lot of research done in past and still in progress to find out all tea benefits.
For example research shows that drinking 3-5 cups of tea per day may lower Low Density Lipoprotein (LDL) cholesterol ("bad" cholesterol) and therefore reduce a risk of heart attack.
Several studies found that people who drunk tea in larger quantities had a much decreased risk of colon cancer.
Tea is also thought to help prevent skin cancer, and possibly other cancers as well, by its antioxidant and anti-mutagenic properties.
Two recent studies found that tea-drinking women had a higher bone mineral density (BMD) than women who didn't drink tea.
Tea is also considered in reduction of dental caries and plaque formation. In laboratory tests, green tea antioxidants inhibited the production of plaque by bacteria. Tea is also naturally rich in Fluoride.