Free radicals are atoms or molecules containing unpaired electrons.
Free radicals, also known simply as radicals, are organic molecules responsible for aging, tissue damage, and possibly some diseases. These molecules are very unstable, therefore they look to bond with other molecules, destroying their health and further continuing the damaging process. Antioxidants, present in many foods, are molecules that prevent free radicals from harming healthy tissue.
Radicals do play a key role in several biological processes. They play a part in the work of the white blood cells called phagocytes, which "eat" bacteria and other pathogens in the body. They also are believed to be involved in a process called redox signaling, where they are thought to act as cellular messengers.
What Are Free Radicals?
Free radicals are everywhere, in the air, our bodies, and the materials around us. They cause the deterioration of plastics, the fading of paint, the degradation of works of art, aging related illnesses, and can contribute to heart attacks, stroke and cancers.
Free radicals are molecules with unpaired electrons. In their quest to find another electron, they are very reactive and cause damage to surrounding molecules. However, free radicals are also useful because they help important reactions in our bodies take place.
The free radical theory of aging holds that the damage that these free radicals do to our cells, particularly the oxidative stress that oxygen-free radicals cause, could be why our bodies age. When we're young, our cells have a defense system known as superoxide dismutase (SOD) but as we get older, SOD doesn't work as well. That leaves the free radicals to have their way with our cells, and when the damage gets to be too much, the cells die and so do we.
If one believes that free radicals bring about aging and disease, then it stands to reason that we could live longer, healthier lives by either eliminating their presence altogether or by investing in mechanisms that will make them disappear. Because free radicals are a natural byproduct of numerous bodily functions, including breathing, the former is impossible. The main point of defense for many years has been antioxidants, so much so that we might as well retire the phrase "an apple a day keeps the doctor away" and consider something along the lines of "a lot of antioxidants keep free radicals away." Antioxidants, such as beta carotene and vitamins C and E, help to clean up and neutralize free radicals.