Free radicals are atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules. Once formed these highly reactive radicals can start a chain reaction, like dominoes.
Free radicals are caused by normal metabolic activity when our food mixes with oxygen and our digestive juices. It happens as a part of our normal daily metabolic activity. Healthy foods from nature such as vegetables, fruits, nuts and seeds contain naturally occuring antioxidants that help neutralize free radicals so they can not cause damage to genetic material in our cells. Free radicals are also caused by consuming fried foods, refined and processed foods that offer no antioxidant protection and food preservatives. Emotional stress, environmental toxins and cigarette smoke also cause large free radical attacks in our bodies. Their constant bombardment on our bodies can cause considerable damage to our cellular DNA.
Our body also produces its own antioxidants as parts of its defense system, the two most powerful are Superoxide Dismutase commonly called SOD and glutathione peroxidase. Healthy foods we eat provide thousands of different antioxidants that protect our cells from free radical damage.