Antioxidants are man-made or natural substances that may prevent or delay some types of cell damage. Antioxidants are found in many foods, including fruits and vegetables.

They are also available as dietary supplements. Examples of antioxidants include
 - Astaxanthin
 - Beta-carotene
 - Lutein
 - Lycopene
 - Selenium
 - Vitamin A
 - Vitamin C
 - Vitamin E

Vegetables and fruits are rich sources of antioxidants. There is good evidence that eating a diet with lots of vegetables and fruits is healthy and lowers risks of certain diseases. But it isn't clear whether this is because of the antioxidants, something else in the foods, or other factors.