Brine is just a mixture of salt and water, and since salt is Paleo, and I have yet to hear of a diet that restricts water, there’s no reason a good brine can’t be Paleo-friendly.
Brine is mostly used for flavoring and preserving food, both of which are good things. No one wants to eat food that’s bland and dry, so we always encourage natural ways of flavoring food, and salt is a staple for enhancing flavor.
Debunking the Salt Myth
Contrary to popular belief, it turns out salt plays no part in elevating our blood pressure. In fact, rather than eliminating salt to the extreme, it’s probably beneficial to include about two teaspoons per day in our diet. Salt does a number of useful things for us, including helping to balance our potassium levels. A proper balance between salt and potassium in our diet is essential for health, and if you’re eating tons of veggies (as you should) you might need a little extra salt.
Even Mark Sisson took on the salt myth.