Free radicals are unstable molecules because they possess one or more unpaired highly reactive electrons. These molecules can steal electrons from other molecules, thereby altering the structure. The molecule that loses an electron becomes oxidized. Oxidation is thought to damage tissues, including neurons, myocytes, and muscle cells. Normally, free radical damage is kept under control by antioxidants, compounds that protect cells from this damage.
Mitochondria are organelles within cell that when damaged, can have devastating effects on the body.
With aging, mitochondria becomes damaged and this can lead to programmed cell death or apoptosis. Mitochondria contain a set of genes that possess the genetic blueprint for the production of proteins and other molecules that are critical to the process of cellular energy production. When the mitochondria fail, cells and tissue can die. Leeuwenburgh's research focuses on finding interventions that prevent the mitochondria from becoming dysfunctional. Basically, by restricting calories and exercising people can live longer.