While green tea contains only a fraction of the caffeine of coffee, it can still improve alertness, energy and concentration. Drinking green tea can also help with high cholesterol, diabetes, high blood pressure and weight loss. Made from the unfermented leaves of the Camellia sinensis plant, green tea contains higher levels of the powerful antioxidants called polyphenols than any other type of tea.
Caffeine in Green Tea
A 1-cup serving of green tea contains about 20 milligrams of caffeine. That is less than one-quarter of the amount found in a cup of coffee, at 95 milligrams of caffeine per serving. Green tea is also lower in caffeine than black tea, which contains about 47 milligrams of caffeine per 1-cup serving. Consuming high amounts of caffeine from any source for long durations can result in symptoms such as insomnia, dizziness, irritability and heart palpitations. The recommended amount of green tea is 2 to 3 cups per day.