The standard soups from most manufacturers are so salty that many dietitians suggest avoiding them altogether.

On a cold winter day, is there any food more comforting than a warm bowl of soup? Just inhaling the steam rising from a bowl of chicken noodle soup brings back warm memories, hearkening back to the way your mother took care of you when you were sick.

But while soups can be among the most nutritious foods on your table, there are also plenty of potential pitfalls lurking in that cup of broth. The most common downfall of soups is their sodium content, and canned soups can be particularly troublesome. A standard red-label can of Campbells Chicken Noodle soup contains 1,780 milligrams of sodium, about three quarters of the daily recommended amount for the average adult.

Most Americans consume far too much sodium as is, particularly if they eat a lot of processed foods. Sodium can raise blood pressure, and those with hypertension are advised to limit their sodium intake even further.

The standard soups from most manufacturers are so salty that many dietitians suggest avoiding them altogether.

I never recommend a regular soup, says Vanessa Vargas, a registered dietitian with Bend Memorial Clinic. There can be your total sodium intake for the day or more than you need in one can of soup.

Federal health officials have taken notice of the sodium content in soups as well. In 1994, the Food and Drug Administration ruled that no food can be labeled healthy if it has more than 480 milligrams per serving, about 20 percent of daily recommended amount. Because many people eat both servings in a standard can of soup themselves, they essentially double that limit.

Rebecca Brody, a Portland-based professor of nutrition, says that while lower sodium soups are a better choice, consumers still need to check the labels.

Youve got to be careful about the canned soups that say low-sodium because a lot of times theyre saying theyre less sodium than the regular soup version, she says. So there may be 33 percent less than whats normal, but it can still be high in sodium.

And many soups are also high in fat. A Campbells Cream of Mushroom soup, for example, contains about 3 grams of saturated fat per can, about the same as a McDonalds hamburger.

The good news is that the demand for healthier soups has influenced food manufacturers. In its most recent report on the soup market, global food analyst Mintel reported that 51 percent of all new soups introduced in Europe and U.S. markets in the second half of 2004 claimed lower fat, calories or sodium content.

But finding a low-fat, low-sodium soup can still be challenging. Many manufacturers proudly tout their soups as 99 percent fat-free but keep them salty to improve taste. And many reduced sodium soups remain high in fat.

Finding a healthy soup might take a little detective work, but they can be found, Brody says. That might include investigating the freezer section.

There are some really good frozen soups, she says. You still have to look at the sodium content because it depends how theyre flavoring it. But there are some brands that have healthier versions of lower fat, lower sodium soups that are frozen.

Many stores also carry nutritious soup bases in a box.

You can just add your own vegetables and beans, and make a really nice quick healthy soup by using a vegetarian type of base, and then throwing in your own low-sodium items, Brody says. Then you dont have all the processed sodium that comes in the canned products.

Soup du jour

Still, with the information on the label of every can, its easier to discern among store-bought soups than restaurant-bought soups. While chain restaurants sometimes provide nutritional breakdowns of their soups, most independent restaurants cant give those kinds of details.

Not only do you not know, but theyre usually making it from a high-sodium bouillon broth, Vargas says. But she says there are ways of making better or worse choices.

On average, a broth-based soup will be your best choice, she says. Soups like chicken noodle or chicken and rice will run about 100 calories a cup and have a manageable fat content.

Starch-based soups, such as bean, split pea or lentil soups, will average about 200 calories per cup, but do offer the benefit of fiber and protein.

Those fibers and protein have the ability to induce satiety, Vargas says. And fiber passes right through you. You dont absorb all those calories.

Cream-based soups could be the worst choice, with an average of 250 to 300 calories per cup and a lot of saturated fat.

Usually theyre made with half and half or heavy cream, or sometimes a melted cheese, she says.

Bisques and chowders are often cream-based as well. The cream-based New England clam chowder will be much higher in fat and calories than the tomato-based Manhattan clam chowder.

Vargas recommends asking whether soups are cream, starch or broth-based when ordering. If you have the time and inclination, cooking soups at home can be the best way to ensure their nutritional quality. You can avoid the heavy doses of salt and take steps to reduce the fat content.

The American Dietetic Association recommends refrigerating soups before they are served so the fat will congeal. Then you can remove it easily with a spoon. Or if youre in a hurry, you can add a few ice cubes to the broth. The fat will rise and solidify around the ice cubes. Each tablespoon of fat removed accounts for about 120 calories, and 13 grams of fat.

If you dont have time to cook soups from scratch, there are good bases sold in boxes in most grocery stores.

You can take those bases as a convenient way to make soups, she says. Puree some vegetables and add them into the soup to make them thicker and add more fiber.

Soups also offer another way of getting vegetables into your diet.

I know personally with my kids, they will tend to eat vegetables in soup, but not vegetables (on their own.), Brody says. I can get some spinach, kale and okra, things they would probably never eat, and sneak them in.

Weight-loss aid

There are plenty of good reasons to eat soup. A national dietary survey found that people come much closer to dietary guidelines on days when they eat soup than on days when they dont. And studies show that people who eat soup as the first course of a meal tend to consume fewer overall calories during that meal.

A study by researchers from Pennsylvania State University found that soup helps people feel full and eat fewer calories.

The researchers served a first course of a chicken rice casserole, the casserole and a glass of water, or just a bowl of chicken rice soup. Even though all three starters contained the same number of calories, those eating soup ate less at the lunch served 17 minutes later.

The body processes hunger and thirst through different mechanisms, says Dr. Barbara Rolls, the nutrition professor who led the study. Clearly, if a beverage is processed by thirst, it will not reduce hunger.

That could be in part because liquids tend to empty from the stomach much more quickly than solids. Even broth-based soups contain enough particles of solid food to be treated by the stomach as a food and not a beverage.

In another study, Rolls found that people who ate soup as their first course in a meal ate 100 fewer calories in that meal compared with those eating the same amount of cheese and crackers or cantaloupe. That alone is enough of a reduction to lose a pound of body weight in five weeks.

The research also helped confirm Rolls findings that it was volume rather than calories that helps us feel full. Rolls has published a book called Volumetrics that outlines an evidence-based eating plan based on high-volume, low-calorie foods, such as soup, that fill you up and keep hunger at bay, without excessive caloric intake.

Soup is different because its released more slowly due to the fact that theres a little fat and pieces of solid food, and vegetables and meat that need to be broken down by the stomach before it moves on, Vargas says. The stomach recognizes it as a food and not a liquid so it processes it more slowly.

Chicken soup and colds

Of course, soups greatest claim to fame is the most-widely used treatment of colds. In a recent survey of more than 20,000 family physicians, two-thirds backed the use of chicken soup for the treatment of colds. The doctors ranked chicken soup second only to water as an effective way to increase fluid intake when sick.

And theres some evidence that chicken soup may have pseudo-medicinal qualities. In 1993, Dr. Stephen Rennard, a medical school professor at the University of Nebraska, was watching his wife make chicken soup using her Lithuanian grandmothers recipe.

She told me the soup was good for colds, Rennard said. Ive heard that a zillion times. Then I started to think, Well, maybe it has some anti-inflammatory value. Everyones heard this from their mother in many cultures. No one seems to have a monopoly on the insight of the value of chicken soup.

He decided to test the family chicken soup as well as several store-bought cans of soup in his laboratory. Rennard found that many of the chicken soups inhibited the movement of neutrophils, a common white blood cell that defends the body against infection. Researchers believe that the reduction in movement of the neutrophils reduces the activity in the upper respiratory tract that can cause symptoms associated with a cold.

The family recipe included chicken, onions, sweet potatoes, parsnips, turnips, carrots, celery, parsley, salt and pepper. But store-bought soups with other ingredients had the same effect.

However, Rennard couldnt figure what compounds in chicken soup were responsible for the effect. Using chicken broth alone did not seem to have any impact.

I think its the concoction, Rennard says.