Dietary Substitution and Longevity
This is interesting, though I have to wonder how it will interact with the findings relating to methionine and calorie restriction in higher animals. Researchers have shown "that yeast cells maintained on a glycerol [rather than glucose] diet live twice as long as normal - as long as yeast cells on a severe caloric-restriction diet. They are also more resistant to cell damage. ... genetically engineered long-lived yeast cells that survive up to 5-fold longer than normal have increased levels of the genes that produce glycerol. In fact, they convert virtually all the glucose and ethanol into glycerol. ... When the researchers blocked the genes that produce glycerol, the cells lost most of their life span advantage. ... [Researchers] believe that the 'glucose to glycerol' switch represents only a component of the protective systems required for the extended survival. ... This is a fundamental observation in a very simple system, that at least introduces the possibility that you don't have to be calorie-restricted to achieve some of the remarkable protective effects of the hypocaloric diet observed in many organisms, including humans. It may be sufficient to substitute the carbon source and possibly other macronutrients with nutrients that do not promote the 'pro-aging' changes induced by sugars."
Link: http://www.eurekalert.org/pub_releases/2009-05/plos-gtg050509.php