Video narration
If people hadn't discovered salt yet, how did your nerves and muscles keep working? Think about your meal: food can contain things you never sprinkled on it. Your body needs sodium, a mineral it cannot make; table salt is one way to get it, but not the only way. Inside your cells, the sodium-potassium pump moves sodium and potassium across cell membranes, helping nerves send signals and muscles contract. Those signals help coordinate ordinary movement. Jens Christian Skou's work on this pump earned him the 1997 Nobel Prize in Chemistry. No salt shaker didn't mean no sodium. Our ancestors got it from food. Hunter-gatherers ate meat and blood, which supplied sodium. So they lived without deliberately collected salt, not without sodium-it came to their meals in the food they ate.