Because of its catechin content, green tea is a potent antioxidant. It is also an anti-bacterial, anti-inflammatory, and stimulant. Green tea has been shown in clinical studies to be capable of preventing or delaying the onset of diseases such as cancer and heart disease. This is due to the catechin component's ability to infiltrate a cell and shield it from free radicals and associated damage.

Green tea is widely used in anti-ageing preparations due to its antioxidant properties. It can also relieve skin swelling when added topically.