What exactly is a "free radical?"
The human body is composed of many different types of cells. Cells are composed of many different types of molecules. Molecules consist of one or more atoms joined by chemical bonds. These bonds are formed by electrons that surround an atom. These electrons surround the atom in pairs, but occasionally an atom loses an electron, leaving the atom with an "unpaired" electron. The atom is then called a "free radical", and it is very reactive because it is looking for a replacement electron. These free radicals rather indiscriminately pick up electrons from other atoms, converting those other atoms into secondary free radicals, and thus setting up a chain reaction that can cause substantial biological damage and aging.
