Antioxidants are essential chemicals that help sustain health and prevent disease. They function by neutralising free radicals, which are unstable chemicals created by the body's normal metabolic processes or by external influences such as pollution, radiation, and cigarette smoke. When free radicals build up, they can create oxidative stress, which harms cells and contributes to ageing and the development of chronic diseases such as heart disease, cancer, and neurological disorders. Antioxidants help to mitigate this damage by stabilising free radicals and keeping them from hurting the body's cells. They are naturally found in a wide range of foods, including fruits, vegetables, nuts, and whole grains. Common antioxidants include vitamins C and E, beta-carotene, selenium, and a spectrum of phytochemicals such as flavonoids.