Role of Natural Antioxidants in Cancer.

The oxidative stress defined as an event caused by an imbalance between production and accumulation of reactive oxygen species (ROS), which lead to a damage in the structure of proteins, lipids, and DNA. Therefore, the production of ROS may alter the normal physiological process by provoking damage to multiple cellular organelles and processes. Oxidative stress has been linked to heart disease, cancer, respiratory diseases, immune deficiency, stroke, Parkinson's disease, and other inflammatory or ischemic conditions. Antioxidants are substances that can prevent or slow damage to cells and tissues caused by ROS, unstable molecules that the body produces as a reaction to environmental and other pressures. The β-carotene, catechins, flavonoids, polyphenols, lycopene, lutein, selenium, vitamins A, C, D, E, and zeaxanthin are all common types of antioxidants and found in plant-based foods, especially fruits and vegetables. Each antioxidant has its own role and can interact with others to process and remove free radicals efficiently. Several studies have been conducted to investigate whether the use of dietary antioxidant supplements is associated with decreased risks of developing cancer in humans, mixed results were reported. For instance, daily use of supplement such as vitamin c, vitamin E, β-Carotene, and minerals such as selenium and zinc have shown its effectiveness by reducing the risk of developing prostate cancer among men and skin cancer among women.