A recent article in Scientific American discusses a synthetic chemical that has extended the lifespan of lab mice by mimicking the effects of a low-calorie diet.

Past research has shown that subjecting test animals to low-calorie diets can extend their normal lifespan by a considerable margin. (There have even been cases of people who have gone on ultra-low-calorie diets to test their effects on human, eating under 1,600 calories per day. See: http://www.nytimes.com/2003/11/23/style/food-for-holiday-thought-eat-less-live-to-140.html).