Long-term caloric restriction (CR) can lengthen life span and reduce the risk of some age-associated diseases such as cancer, diabetes mellitus, and cardiovascular disease.^1-3 The geroprotective effects of CR and CR mimetic drugs such as rapamycin and metformin hydrochloride are accompanied by changes in the amounts of different gene products produced, so that CR or CR mimetic treatment of an older individual can back shift the expression profile to resemble the expression profile of a younger person who is untreated or on an unrestricted diet.^4-7