The extension of maximum life span.
Maximum life span can be increased by dietary modulation in rodents to a degree well beyond what is seen in "normal" laboratory animals, and probably well beyond the "potential" that wildlife animals might achieve if predation could be eliminated. With a fairly high order of probability, the same might be obtained in humans. There is no reason to insist that maximum life span in humans is irretrievably fixed.
D000375:Aging; D000818:Animals; D004038:Diet, Reducing; D006801:Humans; D008136:Longevity; D012098:Reproduction