I think that was sort of their point in that a lot of times you should limit your intake of some things maybe even not eat however you can find recipes and people advocating for them still without pointing this out.Whereas the advice is sound, modern chemical analysis has identified ‘toxins’ in many common foodstuffs; volume of consumption is the thing to watch.
There are many things we consume every day that have the capacity to make you ill
I think comfrey was something they mentioned.