He is probably referring to the added salt typical of these foods. Whether or not he is right about mined salt (non-food bound) I do not know yet. It seems a reasonable theory, but it may be bollocks. More evidence is needed. His case is that salt is purified in the body, and when it is, it becomes highly explosive (pure sodium is very explosive apparently), and eventually explodes in your system, causing cellular damage. Would like to see some evidence for or against.
This is opposed to plant and animal salts, animals getting theirs from plants typically, and plants getting theirs from the soil. Obviously herbivores and some other animals love salt/mineral licks when offered. But the only time they would see something like that in the wild is natural salt flats and ocean water, among a very few others. By and large most wild animals get their salt from diet.