The Truth About Low-Sodium Soy Sauce
Dieticians and health care workers have declared war on sodium, a mineral that is naturally found in foods like celery, beets, and milk. But the medical profession's problem with sodium doesn't involve what occurs naturally in food — their beef is with sodium which is found in prepared or processed foods and which delivers as much as 75 percent of the sodium we ingest today (via Sodium Breakup). In fact, most of the sodium put into our bodies comes from foods such as pizzas, deli meats, snack chips, cheese, and eggs.
To help us cut down on the mineral blamed for our heart problems, some food producers have taken the responsible step of producing low-sodium soy salt. And before you think low-sodium soy sauce is just another food manufacturer's gimmick, one of the world's largest soy sauce producers, Kikkoman, says low-sodium soy sauce is brewed the same way as regular soy sauce — but with 40 percent of its sodium removed. So if a tablespoon of regular soy can have 902 mg of sodium (via Healthline), the same amount of the low-sodium sauce will instead deliver 541 grams of sodium.
Low-sodium soy sauce and light soy sauce can be used interchangeably, but they aren't the same
Keep in mind, though, that light soy sauce and low-sodium soy sauce is not exactly the same thing. The Woks of Life says "light" soy sauce usually refers to Chinese soy sauce, which is thinner and lighter than Japanese soy sauce. In Chinese cooking, there is a difference between light soy and dark soy (which is thick, dark, and sweeter).
But while low-sodium soy and light soy sauce are different, The Woks of Life says light soy sauce and low-sodium soy sauce can both be used interchangeably, but you'll definitely want to use it with caution as dishes prepared with low-sodium soy will naturally end up being less salty. The Woks of Life also recommends that low-sodium soy be added to braised meats which will allow the dish to take the flavor of soy sauce without having it become too salty.
In case you're wondering why low-sodium soy salt wasn't a thing until recently, Chinese cultures have been producing soy sauce for the past 3,000 years, and it's likely producers didn't actually find a way to create a low-sodium version until recently.