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Glossary of Anti Aging TermsThese are compounds that neutralize oxygen radicals. Some are enzymes like SOD while others are nutrients such as vitamin C, vitamin E, and beta-carotene. High levels of these compouds have been associated in research with longer life spans. Anti-proliferative genes Genes that inhibit cell division or proliferation; these are also known as tumor suppressor genes. Average life span The average number of years that members of a population live. Biomarkers These are the biological changes that characterize the aging process. Because biomarkers are considered a better measure of aging than chronological time, studies are underway to identify biomarkers in cells, tissues, and organs. Caloric restriction An experimental approach to studying longevity in which life spans of laboratory animals have been extended by reducing calories while the necessary level of nutrients is maintained. Cell senescence The stage at which a cell has stopped dividing permanently. Chromosomes Structures in the cell's nucleus, made up of protein and DNA, that contain the genes. DNA (deoxyribonucleic acid) A large molecule that carries the genetic information necessary for all cellular functions, including the building of proteins. Damage to DNA and the rate at which this damage is repaired may help determine the rate of aging. Free radicals Molecules with unpaired electrons that react readily with other molecules. Oxygen-free radicals, produced during metabolism, damage cells and may be responsible for aging in tissues and organs. Gene A segment of DNA that contains the code for a specific protein or other product. Gene expression The process by which genes are transcribed and translated into proteins. Age-related changes in gene expression may account for some of the phenomena of aging. Glycation The process by which glucose links with proteins and causes them to bind together, thus stiffening tissues and leading to the complications of diabetes and perhaps some of the physiologic problems associated with aging. Hayflick limit The finite number of divisions of which at cell is capable. Interleukins These are substances secreted by lymphocytes. Their levels vary with age. Lymphocytes Small white blood cells that are important to the immune system. A decline in lymphocyte function with advancing age is being studied for insights into aging and disease. Maximum life span The greatest age reached by any member of a given species. Mitochondria Cell organelles that metabolize sugars into energy. Mitochondria also contain DNA, which is damaged by the high level of free radicals produced in the mitochondria. Proliferative genes Genes that promote cell division or proliferation; also known as oncogenes. Photo-aging The process initiated by sunlight through which the skin becomes drier and loses elasticity. Photo-aging is being studied for clues to aging because it has the same effect as normal aging on certain skin cells. Proteins Molecules make up of amino acids arranged in a specific order determined by the genetic code. Proteins are essential for all life processes. Certain ones, such as the enzymes that protect against free radicals and the lymphokines produced in the immune system, are being studied extensively by gerontologists. Telomeres Repeated DNA sequences found at the ends of chromosomes; telomeres shorten each time a cell divides.
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