Oxidative stress is the cause of many serious diseases such as cancer, Alzheimer's, arteriosclerosis and diabetes. It occurs when the body is exposed to excessive amounts of electrically charged, aggressive oxygen compounds. These are normally produced during breathing and other metabolic processes, but also in the case of ongoing stress, exposure to UV light or X-rays. If the oxidative stress is too high, it overwhelms the body's natural defences. The aggressive oxygen compounds destroy genetic material, resulting in what are referred to as harmful 8-oxo-guanine base mutations in the DNA.