Antioxidants are compounds that may protect cells from damage from free radicals. Exposure to various environmental factors, including tobacco smoke and radiation, can also lead to free radical formation. In humans, the most common form of free radicals is oxygen.
When an oxygen molecule (O2) becomes electrically charged or "radicalized" it tries to steal electrons from other molecules, causing damage to DNA and other molecules. Over time, such damage may become irreversible and lead to disease including cancer.
Antioxidants interact with and stabilize free radicals and may prevent some of the damage free radicals otherwise might cause. Examples of antioxidants include anthocyanins, beta-carotene, lycopene, astaxanthin and many others.
Click here for the ORAC of Selected Foods 2007.
National Cancer Institute Website. Last accessed 4/16/06. http://www.cancer.gov/cancertopics/factsheet/antioxidantsprevention