4. Black Tea
Black tea is good for you in many of the same ways that green tea is. It, too, has caffeine, L-theanine, flavonols, and polyphenols, which are antioxidants. So, it also protects against the development of a number of long-term illnesses, such as type 2 diabetes, cancer, stroke, and heart disease. And it helps the gut and digestion even more than green tea.