ABSTRACT
Life extension due to dietary restriction is observed in a variety of species and may likely represent a very basic biological process. However, there are a number of studies which have measured various physiological and biochemical variables, as well as disease incidence, in normal animals as well as in those whose life span has been increased by dietary restriction. It is of interest to establish whether the various dietary manipulations which increase life span do so by a common biological mechanism. In addition, the life span of 445-day-old female, but not male rats, was increased by decreasing the dietary protein. The sex of an adult animal may also influence its response to dietary restriction in terms of life span. Efforts will be made to relate physiological and biochemical differences between normal and dietarily restricted animals to concepts regarding the causes of biological aging.
