Salt and Sodium in Processed Foods

If you've been told to cut back on your sodium intake, it's more than likely you've been instructed to reduce or eliminate a lot of the processed foods you've been eating, even foods that may not seem salty.

That's because sodium is frequently used as a preservative and as a flavor enhancer, either as salt or a component of certain food flavorings.

Food Preservative

Using salt as a food additive is nothing new—it's been used as a preservative for centuries. In fact, salt was vital in trade and so valuable it was used almost like a currency at times. So how does salt work?

Salt is made up of sodium and chloride ions that reduce something called the water activity of foods. The water activity is the amount of water available for supporting bacteria growth or allowing other chemical reactions to occur.

Salt might also draw water out of any bacteria present, which kills them or, at least, slows them down quite a bit. In addition, salt enhances fermentation, which can be used to preserve foods.

Salt is an effective preservative on its own, but sometimes additional chemicals are necessary. Some of them work just like plain salt does to change the water activity, but others work by altering the chemical reactions that would typically result in spoiled foods and rancid fats. In either case, the end result is food that lasts longer.

You'll find sodium-containing preservatives in a variety of foods including salad dressings, canned foods, baked goods, cured meats, canned meats, cheese, jams, jellies, and fruit fillings. Look at the ingredients listed on the packages.

Flavor Enhancer

Salt is a flavor enhancer that you probably use in cooking or at the table. But that accounts for just a small amount of the average daily sodium intake—less than 25 percent. You can use table salt and stay under the recommended daily sodium intake of 1,500 to 2,300 milligrams as long as you avoid other sodium-containing ingredients.

Some flavorings that don't contain salt still contain large amounts of sodium. Monosodium glutamate strengthens your perception of the umami flavor in savory foods like meat and fish. Sodium acetate is another flavor enhancer that is only slightly salty, but it appears to suppress bitter flavors in foods, so it enhances the perception of sweet flavors.

Soy sauce is also used as a flavor-enhancing ingredient, and it's exceptionally high in sodium. You may also swap for potassium chloride, which has a salty taste but increases your overall potassium intake. Potassium is a nutrient of public health concern because not everyone consumes the recommended 4,700 mg per day.

Watching Your Intake

Look for sodium on the Nutrition Facts label. Even 'reduced sodium' foods can still contain more sodium than you expect. Sodium is listed as milligrams per serving, and that may not mean the whole package. If you eat a whole can of chicken soup, you may actually be eating two or three servings, so make sure you account for all the sodium.

Get smart about sodium by learning to look for it on labels and checking the serving size. Often used as a preservative or flavor enhancer in processed foods, the compound goes by many different names, but ultimately functions in the same way. You may also want to follow the DASH diet.