Is rapamycin found in food, or can you get it naturally through your diet?
Rapamycin is not found in food and cannot be obtained through your diet. If you want to influence the mTOR pathway through what you eat, proteins and leucine are relevant, but that is something entirely different from rapamycin itself.
Rapamycin is not found in food, and you cannot obtain it through your diet. In the available research, rapamycin appears only as the name of a cellular signalling system (mTOR, short for: mechanistic target of rapamycin), not as a nutrient or supplement that you can eat or drink.
That signalling system, mTOR, can be influenced through diet. Certain nutrients activate this pathway: most notably leucine (an amino acid found in large amounts in protein-rich foods), other so-called branched-chain amino acids, proteins in general, and long-chain fatty acids. However, this is something entirely different from taking rapamycin itself. You are not eating rapamycin; you are influencing a system that happens to be named after rapamycin.
Rapamycin itself is a medication that doctors prescribe after organ transplants and for certain conditions. It actually inhibits the very mTOR pathway that nutrients activate. Anyone who wants to experiment with rapamycin for ageing purposes needs a prescription for that, not a different diet.
All claims are based on the provided abstracts (PMID 27659301, 37681443, 36722264, 38803274, 39595578, 26682004, 22643031, 34251643). None of the abstracts describe rapamycin as a dietary component.