Tea is an aromatic beverage prepared by adding cured leaves of the Camellia sinensis plant to hot water. The term also refers to the plant itself. After water, tea is the most widely consumed beverage in the world. It has a cooling, slightly bitter, astringent flavour which many people enjoy. Consumption of tea is probably beneficial to health and longevity given its significant antioxidant, flavanols, flavonoids, and polyphenols content. Antioxidant levels, measured by the lag time for oxidation of cholesterol, is improved by the cold water steeping of varieties of tea. Tea consumption is strongly associated with a calm but alert and focused, relatively productive (alpha wave dominant), mental state in humans. This mental state is also common to meditative practice. The phrase herbal tea usually refers to infusions of fruit or herbs made without the tea plant, such as rosehip tea or chamomile tea. Alternative phrases for this are tisane or herbal infusion, both bearing an implied contrast with "tea" as it is construed here.