Researchers have long known that some lab animals live longer than normal when they receive diets sharply reduced in calories. But in a surprising twist, scientists have now cut short that longevity effect in fruit flies by simply tantalizing them with the aroma of yeast, a fruit fly staple.
Some scientists have suggested that calorie limitation prevents a type of cell damage that hastens death. Other researchers suggest that a different mechanism might be at work. Experiments have shown that interfering with the neural circuitry that's responsible for smell changes low-calorie diets' life-extending benefits in worms.
To investigate whether scent can affect life extension, Sergiy Libert of the Baylor College of Medicine in Houston and his colleagues put fruit flies on strict diets but continually provided with some of the insects with the odor of yeast. Flies that were always exposed to the continuous scent had just 82 percent the longevity of flies smelling yeast only