If you thought that you could eat unhealthy and be sedentary but make up for it with antioxidant-rich green tea, Harvard is here to tell you that you're wrong. Interestingly, however, it seems that those who drink green tea also have healthier lives, so there is an upside of getting on the polyphenol bandwagon–which also includes coffee. Just don't sweeten it up with sugar, and you may reap the heart disease-fighting and diabetes-preventing benefits.