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.