Researchers from University of Wisconsin made a study on middle-aged mice which shows that a low-cal diet keeps the heart young. Calorie restriction is the only proven way of extending the lifespan - and this has been found in primates, mice, spiders and other animals. They show that a low-cal diet prevents the genetic changes that signal the aging of the heart.
Working with middle-aged mice, they used 'gene chip' technology to analyse thousands of genes active in the heart. They found that on a full diet, the pattern of genetic activity alters with aging - for example, making heart cells larger. But when calories are restricted many of these changes were not seen. This may be the first indication, at a molecular level, of how eating less helps you live longer - by prolonging the active life of the heart. What's more, these changes were seen in mice who were middle-aged .