The Health Benefits of Tea
Human use of tea began between four and six thousand years ago. Today, tea is the most commonly consumed beverage in the world (after water) and with good reason. In addition to being a delicious, low-calorie beverage, research has shown that tea has numerous health benefits.
What is tea? We tend to call many beverages “tea”. Technically, tea is the dried and processed leaves of Camellia sinensis, a tree indigenous to Asia. There is also herbal tea - which is not really ‘tea’ at all, but rather an herbal infusion or tisane made from various herbs. Herbal teas may be consumed simply as beverages or for their medicinal properties. Herbal decoctions, as are dispensed from Tao of Wellness, differ from herbal infusions in that they are cooked for a longer period of time and are formulated and consumed specifically for their medicinal, rather than culinary, properties.
There are four main types of actual tea (Camellia sinensis): black, oolong, green and white. Black tea is the strongest in flavor and highest in caffeine content. Black tea is produced when the tea leaves undergo an oxidation process which causes them to turn black. Oolong tea is slightly less oxidized than Black tea and has less caffeine. The term ‘red tea’ may refer to either black or oolong tea, or to Rooibos - which is another plant altogether. Rooibos or ‘red bush tea’ comes from the South African plant Aspalanthus lineari. Green tea is steamed, rolled and dried immediately after harvest so that the oxidation process is halted - allowing the leaves to retain their green color rather than turning black. White tea is the least processed - the young tea buds are simply picked and air-dried.
Tea, like all plant materials, contains numerous chemical compounds called phytochemicals. The health benefits of tea have been mainly attributed to a particular group of phytochemicals called flavonoids. Flavonoids have wide-ranging beneficial effects on the body. They act as antioxidants, meaning that they deactivate free radicals that can cause cellular damage. Other mechanisms for their health benefits are currently being studied. Researchers believe that compounds in tea may reduce cancer promoters and neutralize enzymes that are necessary for tumor growth. In addition, it is also believed that tea contains anti-inflammatory compounds.
Recent research has found that tea may protect against heart disease and many types of cancer, reduce inflammation, reduce blood pressure, increase bone density and boost the immune system. There is enough evidence to become a moderate tea drinker even if only half of these benefits pan out with further research. Which type of tea is the best for your health? It has been speculated that the less processed forms of tea (green and white) contain more beneficial compounds than black tea. However, some prominent tea researchers believe that black tea may have different, but equally beneficial compounds. Studies should clarify these issues in the years to come.
What about caffeine? On average, a cup of black tea contains about one third of the caffeine you would get from the same cup of coffee. Green tea contains about one sixth of that amount. The caffeine content will vary with the particular tea and the brewing time. For more information on caffeine, see the Fall 2003 newsletter.
To get the most health benefits out of your tea, brew it fresh from loose leaves or tea bags. Instant and bottled teas contain less active compounds. To extract the most beneficial compounds from the tea leaves or bags, let them steep for three to five minutes. Beware of bottled, sweetened teas that contain added sugar and extra calories. Drink to your health!