"deficiency in one vital nutrient among a great many can cause other nutrients to be less effectively utilized in the human body..."
The same can be said for an over abundance of any one nutrient... or a congested system be it respiratory, circulatory, elimination, what have you.
But for some reason we just do not ever get that there is no magic bullet or a single cure/fix/fountain of youth. I would be the first to tell you from personal experience that the cleanses can be near miraculous for some people, however they are not the entire answer... the answer is many things;
I changed my diet first, before I did anything else. Doing any or all of the above without first cleaning up ones diet is like throwing a gallon of water on a bonfire... the water may douse the flames for a bit, but the fire will eventually come back just as big as ever.
If you want to have it all, you have to do it all... all would be good, clean, high quality foods, adequate exercise, rest, fresh air, sun, good clean water, and good clean dirt... I bet if one were to do this, they would minimize or even eliminate their needs for cleanses and most all "supplements" save for those difficult to get nutrients through diet alone (these days).
These "fads" are pieces of a puzzle on the road to recovery and are absolutely essential for some people and the reason they cycle as they do here on the zone.