Talk of the Nation's Science Friday interviewed Eric Ravussin, chief of the division of Health and Performance Enhancement at Pennington Biomedical Research Center at Louisiana State University. The discussed Ravussin's research, published recently in the Journal of the American Medical Association, which investigated calorie restriction diets in non-obese humans. After six months, they found indications of better longevity. Click here to listen online.
As he has blogged about before, Dr. Fuhrman believes there is a powerful message behind this kind of science (and advocates taking advantage of this benefit not with tiny portions of the same old unhealthy food, but with lots of foods that have lots of nutrition and very few calories, like fruit and vegetables):
Scientists have known for over sixty years that if you reduce caloric intake below a certain set point while maintaining adequate nutrition you can extend life. This experiment has been performed on numerous species, including primates (we are primates too). In each case, the average animal lifespan was increased 25 - 50 percent. Reducing calories not only extends life it delays the onset of old age. You literally live younger longer. In all clinical studies published to date, animals fed reduced calorie diets were also more disease resistant. Evidence for increased lifespan by caloric restriction is enormous and irrefutable. Calorically-restricted animals are not only more cancer resistant, but oxidative stress is inhibited and youthful features of young tissue are retained with aging.
What is clear is that health and longevity are inversely proportional to caloric intake. Calorie reduction is the closest thing that science has to a fountain of youth. Typical studies suggest that you would have to reduce calories by about 30% to achieve significant life-extending benefits. This means that someone who would normally require 2200 Calories would need to reduce intake to 1800 calories in order to achieve life-extending benefits.
However, it must be noted that if one eats less food that is low or deficient in nutrients and as a result consumes less calories in a low nutrient environment, diseases will appear that will destroy the dramatic effects of caloric restriction.
By the way, Science Friday also had an interesting discussion of something that has come up on this blog a lot: mercury in fish. You can read about that, and listen to it online too.