Before I found this board more of my research was done the old fashioned way: I read books.
Here is one that I found useful in explaining how we got to a place where our food supply is poisoned. My interpretation is that once you had an organization such as the FDA to enforce standards the seller didn't have to convince buyers his product was good. Instead all he had to do was to persuade, cajole or control the agency doing the regulating.
https://press.princeton.edu/books/hardcover/9780691645308/before-silent-spring
Before Silent Spring: Pesticides and Public Health in Pre-DDT America
Quote about the book:'The author shows how economic necessities, technological limitations, and pressures on regulatory agencies have brought us to “our present dilemma of seemingly having to poison our food in order to protect it.”'