Tea, especially green tea, is often said to be good for your health. Tea contains substances linked to a lower risk for heart disease, cancer, and diabetes.
Research studies by Harvard University suggests that tea consumption, especially green tea, may not be the magic bullet, but it can be incorporated in an overall healthy diet with whole grains, fish, fruits and vegetables, and less red and processed meat.
The main health-promoting substances in tea are polyphenols, in particular catechins and epicatechins. Lab and animal studies say these molecules have anti-inflammatory and antioxidant properties. Harvard-led studies of large groups of people over time have found that tea drinkers are at lower risk for diabetes and possibly cardiovascular disease.
One important warning to note a cup of tea contains only a couple calories. Processed, sugar-sweetened tea beverages are loaded with extra calories. "If there are any health benefits to green tea consumption, it's probably completely offset by adding sugar."
Source: Harvard Health Publishing