Oxidative stress is described as a condition in which an imbalance exists between pro-oxidant and antioxidant levels in such a way that prooxidants overwhelm the antioxidant defense. This condition has the potential to lead to the oxidative modification of important cellular components including lipids, DNA, and proteins in ways that may impair cellular function. These pro-oxidants are often collectively referred to as reactive oxygen and nitrogen species, due to their molecular composition and high potential for “reactivity” with other molecules. In the lay press, prooxidants are usually referred to as “free radicals.” Antioxidant nutrients contained within whole foods and nutritional supplements are often recommended to counteract pro-oxidants.