Tea is the common element.
The many years of popularity that tea has enjoyed may have more to do with health benefits than taste. Tea, like many other plants, is coming under investigation for its role in reducing the risk of stroke, certain cancers and heart disease. The antioxidants in tea are the focus of much of the research. In addition, tea is a good source of fluoride which can help strengthen tooth enamel. While tea may have some health benefits, it is a source of caffeine.