The researchers also studied genetically altered strains of fruit flies to determine whether loss of olfactory function ?the sense of smell ?had an effect on lifespan. They found that in all cases, the longevity of the mutant flies was considerably greater than their wild-type controls.
The paper will be published by Science Express, an online publication of the AAAS, on Feb. 1. Science Express is used for rapid publication of selected research papers that are published later in the print version of Science.
Van Voorhies did the metabolic measurements for the study, using sensitive detectors in his laboratory at NMSU to analyze the aerobic respiration of the tiny flies. Carefully controlling the flow and oxygen content of air flowing to the flies in sealed systems, he can determine the flies' metabolic rates by analyzing the carbon dioxide they give off.
At the cellular level, this metabolic process is essentially the same in all organisms. Fruit flies and other short-lived organisms make useful "model organisms" for studies such as this because studying humans is impractical, Van Voorhies noted.
"If you are studying longevity, by definition the study is going to take longer than the lifespan of the researcher," he said.
Van Voorhies said metabolic studies of the fruit flies showed that longer lifespans in those subjected to caloric restriction were not simply a result of slower metabolism.
"A simple way to get a fruit fly to live longer is to put it at lower temperatures," he said. "It will live longer but everything i
Source:New Mexico State University