Studying the underlying mechanisms of aging may be the most efficient and least expensive way to extend the human health span and relieve the suffering that results from age-related diseases. Some of the field’s most exciting areas include research into the metabolic characteristics of aging, especially at the cellular level, and how interventions such as caloric restriction manipulate them. Scientists are taking particular interest in growth hormone, insulin-like growth factor, and the interaction between DNA and mitochondria—the organelles in cells that convert nutrients into energy. Other hot topics include oxidative damage, telomeres and tissue engineering, DNA damage and repair, cellular senescence, immune response, and longevity variations both among and within species.

A biomarker of aging is a biochemical indicator that can help identify rates of aging, predict longevity, and reveal susceptibility to disease. Researchers have made important progress in finding biomarkers of aging in lower life forms, such as roundworms, by looking at genes that turn on and off in age dependent ways. Locating them in humans has proven more difficult, but researchers have made significant progress through studying stem cells and tumor suppressor genes. And exciting new fields such as epigenetics— the study of alterations in gene expression/regulation that go beyond the genetic sequence—are leading to a cascade of new discoveries. Although most scientists agree that finding a single biomarker for the entire complex process of human aging is a long way off, developing a group of them that can predict risk for age-related diseases, such as cancer, Parkinson’s disease, and Alzheimer’s disease, is well within our reach and generating great interest among scientists.