In cells, oxygen is constantly involved in chemical reactions in which electrons are shifted around. This process, called oxidation, creates highly reactive, unstable, harmful particles known as free radicals, which combine quickly with other compounds. Free radicals cause damage and many experts believe damage from free radicals is a factor in the development of blood vessel disease, type 2 diabetes, cancer and many chronic diseases. Free radicals can cause LDL cholesterol to oxidize, increasing cardiovascular risk. They can also damage genes in ways that contribute to the aging process. The damage to cells caused by free radicals, especially the damage to DNA, may play a role in the development of cancer and other health conditions.
We are exposed to free radicals through normal cellular processes, the effects of ultraviolet light and sun exposure, air pollution, trauma, excess heat, and smoking or when the body breaks down certain medicines. Our bodies also produce free radicals during exercise because we inhale more oxygen and use more energy and through by-products of normal processes that take place in your body (such as the burning of sugars for energy and the release of digestive enzymes to break down food). To generate energy, our cells remove electrons from sugars, fatty acids, and amino acids and add them to other molecules, especially oxygen. All this creates free radicals.
Antioxidants to the rescue. Antioxidants are the heroes of the complex world of biochemistry. Antioxidants protect the body from damage caused by free radicals. Thus, antioxidants may play a role in the management or prevention of some medical conditions, such as some cancers, heart disease, macular degeneration, Alzheimer’s disease, and some arthritis-related conditions.
It takes a variety of antioxidants and lots of them to help successfully deactivate the different kinds of free radicals. The body’s natural antioxidant defense system is partly fueled by the antioxidants we consume. Antioxidants include vitamin C, vitamin E, beta carotene, lutein, lignin, lycopene, and other carotenoids, and selenium. In general, the best dietary sources of antioxidants are vegetables, fruits, grains, beans, seeds and other plant-derived foods.