Source: media-newswire.com Author: K. Sandeep Prabhu Blueberries, pomegranates, green tea and dark chocolate -- these are just some of the antioxidant-rich "superfoods" found in almost any supermarket today. As well as improving our general health, there is growing evidence that diets high in antioxidants may confer some protection against a long list of chronic diseases, including Alzheimer's disease, cancer and even HIV. Given their increasing popularity, the fundamental question bears asking: What exactly are antioxidants, and how do they work in our bodies? Antioxidants come in several forms, including the vitamins A, C and E; plant-derived polyphenols, found in colorful fruits and vegetables; and also the element selenium, found in nuts and broccoli. "What these compounds share," explained K. Sandeep Prabhu, Penn State assistant professor of immunology and molecular toxicology, "is the ability to neutralize harmful molecules in our cells." These harmful molecules, known as free radicals, contain unpaired electrons -- which is unusual because electrons typically come in pairs. "The unpaired electrons make free radicals highly reactive, and in this state, they can cause damage by attacking the components of our cells, and can even cause cancer," Prabhu said. So where do free radicals come from? Some are created as a natural by-product of reactions in our cells, said Prabhu. Other sources of free radicals include cigarette smoke, air pollution and exposure to UV light or radiation. Once free radicals are formed, they can make more free radicals by scavenging electrons from other molecules, "creating a domino effect," he [...]