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Caloric Restriction May Extend Life But Not Youth

Super-low calorie diets may extend lifespan, but new evidence suggests that age-related declines continue. Karen Hopkin reports.

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For decades scientists have known that animals on a severely restricted diet live longer than their gluttonous cousins. If you cut the number of calories you consume by a third you can add about 30 percent to your lifespan—at least if you’re a rat, a worm, or a fly.  Sounds easy. But there’s a catch. Well, a bunch of ‘em, actually. For starters, cutting that many calories—without becoming malnourished—is a trick that few of us would be able to pull off.

And if that’s not enough, scientists at Virginia Commonweath University in Richmond have discovered that fruit flies on a restricted diet do live longer—but, unfortunately, they continue to act their age. As flies grow older, they lose their memory, as well as their ability to walk and to smell things. And eating less banana mash doesn’t make their lives any sweeter.  In the Virginia researchers’ hands, the calorically challenged, longer-lived flies continued to show age-related declines in their ability to climb walls and to avoid bad smells, results that appear in the October issue of the journal Aging Cell.  Just something to keep in mind before you decide to pass on the apple pie a la mode…and pretty much everything else you might be thinking about eating today.

Caloric Restriction May Extend Life But Not Youth