English breakfast tea offers a significant concentration of theanine, an amino acid that may help a person to relax and bring about a sense of overall well-being. A single cup of black tea commonly contains 35 to 50 milligrams of caffeine, and studies have shown theanine's ability to enhance the effects of caffeine while keeping us calm, sharpening our focus and placing us in a state of alert relaxation.
Black tea is also loaded with catechins – typically 20 to 28 milligrams per cup. These polyphenols are anti-inflammatory alkaloids that could reduce oxidation in the body, slowing the cellular signs of aging. According to at least one study, catechins may also boost energy and enhance an individual's metabolism.
