Research on rats and calorie restriction diets first began in the 1930's at Cornell University. Since then, thousands of studies have been conducted and virtually all confirm that, "Animals that are placed on calorie-restriction life-styles have less cancer, arteriosclerosis, and immune system disorders".

Longevity studies have consistently demonstrated that rodent life-spans can be increased by 30-50 percent by simply reducing the amount of food that the mice eat.

It is interesting that the animals not only lived longer ... they lived "better". For example, muscle strength and coordination in 31 to 35 month old mice was equal to mice that were only 11 to 15 months in age. Also, they performed as well on maze tests.

WHY DOES CALORIE RESTRICTION WORK? One theory is that food deprivation allows the body to direct it's energies from "growth and reproduction" to "maintenance and repair".

Another theory holds that destructive free radicals are produced when the body goes through the digestive process - i.e., limiting the amount of food limits the production of free radicals.

WHAT ABOUT OTHER ANIMAL TESTS? Ongoing studies at the University of Wisconsin and the NIA using monkeys as subjects may give us a better idea. The monkeys, studied for 10 years, have demonstrated a lower rate of diabetes than their regularly fed counterparts. They've also maintained higher than normal levels of the hormone DHEA, which is associated with youth, according to Mark Lane, PhD, head of nutritional and molecular physiology in the Laboratory of Neurosciences at the NIA and principal investigator on the study.

CONCLUSION(S): It is likely that a calorie restricted diet (that does not cause malnutrition) is the best bet to extend longevity. Studies indicate that a 30% decrease of calories is required to gain significant benefits. Calorie restricted diets will extend life spans in insects, amphibiams and "mammals". Now, it is true that rodents and monkeys are not human ... but they are "mammals" ... it is virtually certain that the same factors that extend the life spans of rodents will also contribute to longevity in humans.

My work with "meditation" supports the "calorie restricted diet" (see "JKL 2/1 fast diet"). Quieting the Mind and Body to allow the body to heal itself is a basic philosophy of meditation ... and a study conducted in England concluded that meditators had a "real" age that was far less than their chronological age.

My work with "fasting" also supports the notion that alleviating the digestive process is actually therapeutic.

So there you have it ... the only thing that has ever been scientifically proven to extend animal life-spans is "calorie restriction".