Because table salt comes from the same batch as vacuum-refined industrial salt, it is treated with caustic soda or lime to remove all traces of magnesium salts. These vital magnesium salts are NOT taken out because they keep the salt from flowing out of the dispenser spout (a common myth)... Magnesium salts are removed because they bring in more profits on the chemical market. Yet these magnesium salts are a very necessary part of the food salt and fill important biological and therapeutic roles. Further, to prevent any moisture from being reabsorbed, salt refiners now add alumino-silicate of sodium or yellow prussiate of soda as desiccants plus different bleaches to the final salt formula.
But since table salt, chemically treated in this way, will no longer combine with human body fluid, it invariably causes severe problems of edema (water retention) and several other health disturbances. The fear of salt that we witness today and the virtual ban on consuming products with a high sodium content is a matter of serious concern to biologists.
Salt-free diets can cause salt starvation, which is a stark reality of our modern world, but it is actually a starvation of macro- and trace minerals, a biological deficiency that refined sodium chloride alone cannot correct.
Natural sea salt does combine with human body fluid (so it doesn't cause edema) and has not been chemically treated or contain chemical additives. Todd and I always look for pure sea salt - with absolutely nothing added. You can buy it in bulk and Fred Meyer, Whole Foods or PCC. Someday I would love to try some fleur de sel which is French for flower of salt. It's apparently the most coveted sea salt on the planet, but unfortunately it's really expensive. Hmmm... wonder if you can really taste the difference?