What Are Salt Substitutes Made of and Are They Healthier Than Real Salt?

“Real” salt is sodium chloride. The issue of safety revolves around its sodium content; no one has ever blamed the chloride for anything. The aim of all the substitutes is to lower or eliminate the sodium.

Sodium in the diet has long been suspected as a possible cause of high blood pressure, but there appears to be little consensus among medical researchers. Some believe that sodium contributes to high blood pressure and some don’t. While no smoking gun evidence has yet been uncovered, opinion seems to be swinging toward the sodium is bad side of the fence.

As in all health research, the worst that can be said of a dietary practice is that it increases the risk of something or other. That doesn’t mean “eat it and die.” Risk is only a probability, not a certainty. Nevertheless, cutting down on sodium may well be a prudent thing to do.

The medical uncertainties haven’t stopped our vast national food mill from grinding out fear of sodium products. Salt substitutes are usually potassium chloride, a chemical fraternal twin of sodium chloride. It tastes salty, but with a different kind of saltiness.

Both are members of a large chemical family called salts; we call sodium chloride “salt” as if it were the only one because it’s by far the most common. But you can hear chemists laughing as they pass the supermarket shelf where NoSalt is sold; it is potassium chloride, an honest-to-god chemical salt, but its label claims that it is “salt-free.” That’s only because the FDA allows labels to use the word salt to mean sodium chloride and nothing else.

Morton’s Lite Salt Mixture is a 50-50 mixture of sodium and potassium chlorides, for those who want to cut down on sodium but retain some of sodium chloride’s unique flavor.

And finally, there is Salt Sense, which claims to be 100 percent “real salt” (meaning real sodium chloride), yet also purports to contain “33 percent less sodium per teaspoon.” That statement is disconcerting to a chemist, because sodium chloride is made of one atom of sodium plus one atom of chlorine, which means that sodium chloride must always contain the same percentage of sodium by weight: 39.3 percent. (It’s less than 50 percent because the chlorine atom is heavier than the sodium atom.) So there’s just no monkeying around with how much or how little sodium “real salt” contains. It would be like claiming that a certain dollar contains less than 100 cents.

So what’s the trick? It’s in the word teaspoon. A teaspoon of Salt Sense does indeed contain 33 percent less sodium, because a teaspoon of Salt Sense contains 33 percent less salt.

Salt Sense consists of salt crystals that are flaky and fluffy, so they don’t settle down into the spoon as much as ordinary granulated table salt does. So if you use the same volume, or bulk, of Salt Sense that you do of ordinary salt, it’s actually less weight and, hence, less sodium. It’s just as if a brand of ice cream claimed to have 33 percent fewer calories per mouthful because it’s frothed up with more air (yes, they do that) and there is therefore less ice cream in a mouthful.

In tiny print at the bottom of the Salt Sense label, there’s a footnote: “*100 grams of either product [Salt Sense or regular salt] contains 39,100 milligrams of sodium.” Right. When you take equal weights, rather than an equal number of teaspoonfuls, Salt Sense is nothing but salt with an additive: creative marketing.

Okay, you nitpickers, you’ve noticed that 39.1 isn’t exactly 39.3. That’s because Salt Sense is only about 99.5 percent pure.