If you or one of your family members has high blood pressure, you probably know all about the challenges of avoiding added salt in modern-day prepared foods. Yet salt is critical for life and has always been a critical part of human society.
The earliest-known pharmaceutical text, the Peng-Tzao-Kan-Mu, written about 5,000 years ago in China, described 40 kinds of salt and their properties. The ancient Greeks traded slaves in exchange for salt, which gave rise to the expression, “not worth his salt.” Marco Polo found salt cakes stamped with the imperial seal of Kublai Khan used as money in Tibet; and in Timbuktu, on the southern edge of the Saharan desert, salt was once traded ounce for ounce for gold. Salt enabled the early Europeans to fish the Grand Banks in Newfoundland since they could preserve their catch for the long journey home. In this respect, salt could be considered one of the first antibiotics used by humans, since it was used to kill the bacteria that would have otherwise caused the fish to spoil.
Common table salt is made up of one part sodium and one part chloride atom. It is one of the four basic flavors that all humans appreciate, along with sweet, sour and bitter. Salt is present in all the fluids and tissues of our bodies and is necessary for normal functioning of our organs. Our heart needs it to beat and our brain needs it to think. Yet too much salt can contribute to blood-pressure problems. So we ask our patients to avoid added salt and to read food labels regarding salt content.
Dietary salt is measured and displayed on food labels as milligrams (mg) of sodium. The current recommendation is that we consume less than 2,400 mg of sodium daily. That is only about one teaspoon, and this includes all salt — salt naturally present in foods, salt added to processed foods, salt used in cooking and salt added at the table. For someone with high blood pressure, a lower target — 1,500 mg daily — helps keep blood pressure down and helps blood pressure-lowering medicines work more effectively.
Salt is present in almost all of our foods. Even natural unprepared foods have some salt. Milk, a natural body fluid, has about 160 mg of sodium per cup.
Some foods are obvious culprits. Pretzels wear their salt right on the surface, and we eat potato and corn chips as much for the salty flavor as for the flavor of the baked or fried starch. But there is a surprising amount of salt in most sauces or condiments, such as spaghetti sauce and catsup. Most canned foods, including soups, stews and vegetables, are rife with added salt, sometimes 300 to 1,000 mg per serving. Prepared meats such a cold cuts and sausages are also chock full of salt.
Always read the food label for sodium (salt) content. Always check the serving size and servings per container. Though some prepared foods may appear to have only a modest salt content, a review of the food label may reveal many servings per container. If you are consuming more than one serving, your actual salt intake could be much higher than the number listed on the label. Fast foods are probably the worst offenders. It is not uncommon for fast food meals to have 1,000 to 2,000 mg of sodium in one serving.
While salt has been a critical part of human history and is critical to our body’s physiology, we want to make sure we avoid “too much of a good thing.” For additional information on the impact of salt on health, visit the following websites.
http://www.cdc.gov/features/sodium/
http://www.nhlbi.nih.gov/hbp/prevent/sodium/sodium.htm
http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm181577.htm
— Bill Black, M.D., Ph.D.