From the Guidelines
Yes, green tea contains caffeine. The amount of caffeine in green tea can vary, but according to the evidence provided by 1, brewed green tea typically contains 25-50 mg of caffeine per 8 oz serving. This is significantly less than the amount of caffeine found in brewed coffee, which can range from 50 to over 300 mg per 8 oz serving. The evidence from 1 also supports this, listing the caffeine content of green tea as 25-50 mg per 8 oz serving. It's worth noting that these values are for brewed green tea, and the caffeine content may vary depending on factors such as the type of tea leaves, brewing method, and steeping time. However, in general, green tea is considered to be a low-caffeine beverage option.
From the Research
Caffeine Content in Green Tea
- Green tea does contain caffeine, although the amount can vary depending on factors such as serving size and steep-time 2.
- Studies have shown that the caffeine concentration in green tea can range from 14 to 61 mg per serving (6 or 8 oz) 2.
- Decaffeinated green teas typically contain less than 12 mg of caffeine per serving 2.
- The caffeine content in green tea can also be affected by the decaffeination method used, with some methods reducing caffeine levels more effectively than others 3.
Variations in Caffeine Content
- Different types of green tea can have varying levels of caffeine, with some studies showing that caffeine content can range from 28 to 183 mg per tablet or capsule in green tea dietary supplements 4.
- The caffeine content in green tea can also be influenced by factors such as the amount of tea leaves used, the steeping time, and the temperature of the water 5.
- Some studies have suggested that the combination of caffeine and catechin-polyphenols in green tea may have synergistic effects on thermogenesis and weight loss 5.