Life Extension Update Exclusive Resveratrol works on roundworms and fruit flies, too Readers of the August 26 2003 issue of Life Extension Update may recall the question asked in that issue’s “Life Extension Update Exclusive” headline: “Polyphenols mimic calorie restriction in yeast... will they do the same in humans?” The article summarized a report published in the journal Nature (http://www.nature.com), which revealed the findings of David Sinclair and colleagues that yeast cells treated with the polyphenol resveratrol lived 60 to 80 percent longer than their normal lifespan of nineteen generations. In a new series of experiments, also conducted by Dr Sinclair and recently published online in Nature, it was found that resveratrol extends the lifespan of the roundworm C elegans and the fruit fly Drosophila melanogaster, bringing us a little closer to the answer to the question concerning whether resveratrol will similarly benefit higher species. Resveratrol is one of several compounds that activate Sir2-like proteins (known as sirtuins), which have been found to be active in calorie-restricted organisms. Greater sirtuin activity within a cell is associated with increased survival. In the current series of experiments, Sinclair and colleagues demonstrate that sirtuin activating compounds increase the in vitro activity of Sir-2.1 and Sir2 purified from the roundworm and the fruit fly. In further experiments, the team administered diets with or without resveratrol to roundworms and observed an extension of lifespan of up to 14 percent in worms who received the compound compared to the control group. When the effect of resveratrol was examined in fruit flies on abundant diets, the lifespan of flies who received the compound was extended up to 29 percent. While male and female flies on calorie restricted diets experienced an average extension of lifespan of 10 and 40 percent, respectively, the addition of resveratrol to the regimen did not increase longevity. The authors write that this finding “suggests that resveratrol extends lifespan through a mechanism related to calorie restriction.” Interestingly, the female flies who received resveratrol experienced an increase in egg production, which contradicts other experimental findings that regimens that extend lifespan reduce fertility. This research demonstrates in multicellular animals that it may be possible to elicit some of the benefits of calorie restriction without eating less by utilizing sirtuin-activating compounds such as resveratrol.
|