Salt is what makes a brine. The idea is that salt from the brine migrates into the meat because there is a lower concentration of salt in the meat than the brine. Then, the salt begins to denature some of the meat proteins, the solute level increases in the meat, and some water is drawn back into the meat, which in theory makes it juicier after cooking.
But honestly, depending on what you want to brine, I would suggest just not brining it at all. If you're talking about chicken, we never brine chicken--we find we get better results (and crispier skin) from drying off the outside of the bird really well and sprinkling the seasonings directly on the skin. We don't even brine turkey anymore. I think my husband and I have both come to the conclusion that brined meat is sort of mushy and not as flavorful as when you just put the seasonings on the skin.
Sorry I couldn't give you a recipe for a low-sodium brine. Just thought you might want to reconsider brining overall. It's not a necessary practice. There are other ways of keeping meat juicy and flavorful.
absolutely right. brine= salt like candy= sweet