Antioxidants are by definition the substances that inhibit oxidation. Oxidation is also known as the process where oxygen contains molecules that have an uneven number, called free radicals. These are dangerous due the large chain reactions they can cause within the body. Antioxidants help by neutralizing the free radicals within the body, which lowers the risk of many oxidative-stress related diseases such as cancer and cardiovascular disease. They are also known for boosting the immune system and improving overall health as well as contributing to healthy aging.