There are many recent studies that show that drinking green tea may have beneficial affects on the brain. Green tea contains a bioflavonoid called catechin, which is a powerful antioxidants that can help prevent damage to the brain caused by free radicals. This damage can lead to problems such as dementia and Alzheimer's disease.

Green tea is also one of a handful of substances that can reduce levels of nitric oxide in the brain. Nitric oxide is an important neurotransmitter that contributes to memory formation, but too much nitric oxide can cause certain neurodegenerative disorders.

Some research even indicates that green tea may protect against Parkinson's disease by cleaning up excess iron in the nervous system.

Other studies have suggested that the antioxidant characteristics of green tea may also help to prevent against certain types of cancers, heart problems, high cholesterol and hypertension.

Black teas contain most of the beneficial elements of green tea, but to a lesser extent depending on how the tea is processed. For people sensitive to caffeine, there are many decaffeinated brands on the market that preserve the positive properties of the tea.