Salt Kicks Hypertension Up A Notch

That will help, but it's not nearly enough, say a doctor and dietitian from the University of Michigan Health System. The bigger problem, they say, is that salt hides in a range of foods -- including soup, cereal, frozen dinners and canned vegetables -- and the result can be higher blood pressure in people with hypertension (high blood pressure).

"When you look across whole populations, societies where people don't eat much salt have lower blood pressures than places where people eat a lot of salt," says Lee Green, M.D., MPH, associate professor of family medicine at the U-M Medical School. "Salt convinces your body that your blood pressure ought to be higher."

Hypertension affects more than 50 million Americans, Green says, and is the number one disease issue that primary care physicians see in their patients.

"Because hypertension is an enormous contributor to strokes, heart failure and heart attacks, that makes controlling it a great problem for patients and for physicians," Green says.

Many people would be surprised to learn about the amount of salt in some pre-packaged foods, says Lynn Glazewski, R.D., MPH, a dietitian with the U-M Health System. Some types of healthy-seeming breakfast cereals, such as some varieties of raisin bran, have more than 350 milligrams of sodium per cup. Dietary guidelines say that people should consume no more than 2,400 milligrams a day.

Canned soup can have almost 1,000 milligrams of salt per one-cup serving, which is less than the amount people often eat as a serving. Even some low-sodium soups have about half that amount, which is still substantial, Glazewski says. Some specialty soups have just 140 milligrams per cup, she notes.

"If you don't have time to make homemade soup, it's worth your while to check the labels of all the products available to you and make the wisest choice," she says.

When you're searching for vegetables, the best idea is to go to the produce section of the grocery store, rather than the canned-food aisle, Glazewski says. Many canned vegetables contain 300-400 milligrams of sodium for a half-cup serving, she says, while fresh vegetables contain close to zero.

For those who think of rice as a healthy, wholesome food -- well, it is, but only the natural kinds of rice. Many popular packaged rice dishes include flavor packets, an addition that can boost the sodium levels to about 750 milligrams.

Other big sources of sodium include salad dressings, which can have 500 milligrams or more of sodium, and prepared frozen meals, which can contain more than half the recommended allotment of sodium in a single serving. Glazewski suggests making your own dressing with oil and vinegar and looking for lower-sodium frozen meals.

One thing to watch out for, ironically, is the low-calorie section of the frozen food aisle, she says. "If you're going to choose a light product, you have to be aware that some of the products that are lower in saturated fat and lower in calories may have just as much sodium or more than a comparable higher-fat, higher-calorie product," Glazewski says.

In short, she says, look at the label and learn to be a smart consumer. And both Green and Glazewski note that looking at the label isn't always possible, such as when you're dining at a restaurant.

"Restaurant food is quite heavily salted, much more so than people realize," Green says. "We need to start insisting that restaurants tell us how much salt is in food, and we need to insist that food be labeled so we can tell how much we're getting."

Facts about hypertension and sodium:

* Hypertension -- or high blood pressure -- is a reading of 140/90 or higher.

* About one-third of American adults have high blood pressure.

* Tips for reducing salt in your diet include cutting back on processed foods, looking for the lower-sodium versions of frozen dinners and canned soups, adding herbs and spices to dishes instead of salt, reducing intake of salty crackers and snack foods, and eating fresh foods.

* Choose steamed or grilled dishes at restaurants; avoid soups, stir-fry dishes, and foods with salty dressings or dipping sauces.

For more information, visit these web sites:

UMHS Health Topics A-Z:

High blood pressure: Low-sodium diet http://www.med.umich.edu/1libr/aha/aha_hpt-nacl_car.htm

Dietary Approaches to Stop Hypertension (the DASH Diet): http://www.med.umich.edu/1libr/aha/aha_dashdiet_car.htm

National Institutes of Health information about hypertension: http://www.nlm.nih.gov/medlineplus/ency/article/000468.htm

National Institutes of Health information about dietary sodium: http://www.nlm.nih.gov/medlineplus/dietarysodium.html

High-sodium restaurant foods: http://www.cspinet.org/salt/hsrestaurant.html