DEAR DR. BLONZ: My husband has high blood pressure and is watching his salt intake. He thinks he is being careful by not adding salt to his foods, but to me, that is only the most obvious part; it is all the hidden sodium I am concerned about. Processed foods and condensed soups have a lot of sodium, but since it is not in a form that means anything to us, it doesn't really hit home how much it is. If I could picture the sodium in a frozen dinner entree, for instance, in spoonfuls rather than milligrams, that might help. How many milligrams of sodium are there in a teaspoon of salt? -- K.M., Sedona, Ariz.
DEAR K.M.: With the exception of sugar, we add more salt to our food than any other condiment. There are 2,325 milligrams of sodium in one teaspoon (6 grams) of salt. The Daily Value -- that single set of values developed for use on food labels -- recommends an upper limit for sodium of 2,400 milligrams per day. Our health can be maintained with as little as one-tenth of that teaspoon of salt per day. As a country, we are consuming much more sodium than is necessary: The average sodium intake in the United States is between 4,000 and 5,000 milligrams per day.
About 10 percent of the salt we eat is naturally present in food, and 15 percent is added during cooking and at the table. The remainder, 75 percent of the salt in our diet, comes from processed foods.
Salt is added to processed foods for a number of reasons. Depending on the level used, it can slow the growth of certain microorganisms. Before refrigeration, salting was the only practical way to keep meat and fish from spoiling. Salt can also play a role in food texture: Processed meats such as bologna, hot dogs and lunch meats contain higher levels of salt because it helps maintain the consistency of the product. Then, of course, there is salt's role as a flavor enhancer.
The concern about excess salt is its association with hypertension, or high blood pressure, which currently affects about 50 million Americans. Hypertension is defined as blood pressure readings above 140/90. The first number (140, in this case) is the measure of the pressure in the arteries when the heart contracts and the second number (90) is the pressure in the arteries as the heart relaxes between beats.
Hypertension is called "the silent killer" because there are no warning signs until problems such as heart disease, stroke or kidney disease have already developed. There is more information at tinyurl.com/d7o7mmb. The only reliable way to find out whether you have hypertension is to have regular blood pressure checks.
Impressive data coming out of DASH (Dietary Approaches to Stop Hypertension) studies show how blood pressure can be lowered by decreasing sodium intake along with a low total- and saturated-fat diet rich in fruits, vegetables and low-fat dairy.
The bottom line? Read your labels, avoid foods overloaded with sodium and try to focus on the natural flavor of food -- not that which comes from the salt shaker.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.