Antioxidants refers to compounds or molecules that help neutralize the effects of free radicals or ROS in the body. An antioxidant essentially is a molecule stable enough to donate an electron to a rampaging free radical and neutralize it, thus reducing its capacity to damage. Anti-oxidants come in various shapes and forms as well.
However, as the body ages or matures, its internally generated anti-oxidant levels decline, resulting in an imbalance between anti-oxidants and pro-oxidant molecules. This results in oxidative stress, which perpetuates this vicious cycle by in turn, further reducing the scavenging capacity of antioxidants. Therefore, supplementation with anti-oxidants in your diet or through other mechanisms may help to alleviate oxidative stress.
The predominant phytochemicals or anti-oxidants present in tea are catechins, theaflavins and thea-rubigins. Studies have found various health benefits of each of these phytochemicals present in tea.