Given what we know about clinical nutrition, that sometimes a startling mix of foods can be used to help people in certain disease states — more ice cream and gravy for someone
undergoing cancer treatment,
less protein and fewer vegetables for someone with kidney disease — and since dividing your risk among a wide variety of different foods can help hedge your health bets, the idea that there are universally good or bad foods doesn't hold up well under
scrutiny.
In this way, certain assumptions, theories, and findings can become the entrenched wisdom in a field, not because they are correct but because they have consistently
undergone less critical
scrutiny.