My niece told me that also, and she does not want to eat anything that is salty. I think our bodies need a certain amount of salt to retain water, to wash our cells.
It was a joke on the internet. But to diffuse this from blowing out of proportion, I would say that all living beings have salt, minerals, water, air etc..... you name it, going through us and recycling throughout the environment.
I don't think anyone should dwell on that particular instance whether it is true or not.