> The changing of the oil is an understandable analogy, but it ignores the engine's inability to replace oil and manufacturer new oil itself. The body can repla

> The changing of the oil is an understandable analogy, but it ignores the engine's inability to replace oil and manufacturer new oil itself. The body can replace blood cells and manufacturer new blood cells True enough, but what the body can't do, under this idea, is get rid of any harmful waste that the kidneys and liver can't deal with. They're both quite good at their job, but they can't eliminate everything. There's experimental evidence for this. Some of the earlier studies on transfusing in "young blood" were repeated, but with saline and albumen instead of the "young blood". The same benefits were seen. > We just need the right diet How is the right diet supposed to remove waste products that the standard excretory system can't deal with? Also, there have been people eating just about every conceivable diet for a very long time. They all got old.