Via EurekAlert!: "Aging yeast cells accumulate damage over time, but they do so by following a pattern laid down earlier in their life by diet as well as the genes that control metabolism and the dynamics of cell structures such as mitochondria, the power plants of cells. These research findings [support] the theories that old age is the final stage of a developmental program AND the result of a lifelong accumulation of unrepaired cellular and molecular damage. ... The scientists first identified a mechanism closely linking life span to the dynamics of such lipids as cholesterol, triglycerides and fatty acids ... These fatty acids are constantly synthesized in the endoplasmic reticulum (ER), the cell's protein manufacturing factory. ... Low-calorie diets, which have been shown to increase lifespan and delay age-related disorders in nonhuman primates and other organisms, altered the way fats were processed in the yeast cells. The researchers assessed calorie restriction along with a number of known mutations that extend yeast lifespan against a variety of age-related changes in fat metabolism and lipid transport. ... Through the yeast model, [researchers] identified five groups of novel anti-aging small molecules that significantly delayed aging."

Link: http://www.eurekalert.org/pub_releases/2008-12/asfc-bta111908.php