Monday, April 26, 2010

How much salt is too much?

You've been trying to eat less sodium — just a pinch of table salt on your baked potato and a dash to your scrambled eggs.
But a pinch and a dash can quickly add up to unhealthy levels of sodium, especially when many foods already contain more than enough sodium. About 11 percent of the sodium in the average U.S. diet comes from adding salt or other sodium-containing condiments to foods while cooking or eating. But the majority of the sodium — 77 percent — comes from eating prepared or processed foods that contain the mineral. So even though you may limit the amount of salt you add to food, the food itself may already be high in sodium.
Are you getting too much? Here's where sodium sneaks into your diet and ways you can shake the habit.

Sodium: Essential in small amounts

Your body needs some sodium to function properly. Sodium:
  • Helps maintain the right balance of fluids in your body
  • Helps transmit nerve impulses
  • Influences the contraction and relaxation of muscles
Your kidneys regulate the amount of sodium kept in your body. When sodium levels are low, your kidneys conserve sodium. When levels are high, they excrete the excess amount in urine.
If your kidneys can't eliminate enough sodium, the sodium starts to accumulate in your blood. Because sodium attracts and holds water, your blood volume increases. Increased blood volume, in turn, makes your heart work harder to move more blood through your blood vessels, increasing pressure in your arteries. Certain diseases such as congestive heart failure, cirrhosis and chronic kidney disease can lead to an inability to regulate sodium.
Some people are more sensitive to the effects of sodium than are others. People who are sodium sensitive retain sodium more easily, leading to excess fluid retention and increased blood pressure. If you're in that group, extra sodium in your diet increases your chance of developing high blood pressure, a condition that can lead to cardiovascular and kidney diseases.

How much sodium do you need?

Various organizations, including the National Academy of Sciences' Institute of Medicine, have published recommendations on daily sodium limits. Most recommend not exceeding the range of 1,500 and 2,400 milligrams (mg) a day for healthy adults. Keep in mind that the lower your sodium, the more beneficial effect on blood pressure.
If you are older than 50, are black or have a health condition such as high blood pressure, chronic kidney disease or diabetes, you may be more sensitive to the blood pressure raising effects of sodium. As a result, aim for a sodium limit at the low end of the range recommended for healthy adults. Talk to your doctor about the sodium limit that's best for you.

Three main sources of sodium

The average U.S. diet has three main sources of sodium:  
  • Processed and prepared foods. Most sodium in a person's diet comes from eating processed and prepared foods, such as canned vegetables, soups, luncheon meats and frozen foods. Food manufacturers use salt or other sodium-containing compounds to preserve food and to improve the taste and texture of food.
  • Sodium-containing condiments. One teaspoon (5 milliliters) of table salt has 2,325 mg of sodium, and 1 tablespoon (15 milliliters) of soy sauce has about 900 to 1,000 mg of sodium. Adding these or other sodium-laden condiments to your meals — either while cooking or at the table — raises the sodium count of food.
  • Natural sources of sodium. Sodium naturally occurs in some foods, such as meat, poultry, dairy products and vegetables. For example, 1 cup (237 milliliters) of low-fat milk has about 107 mg of sodium.

Be a savvy shopper: Find the sodium

Taste alone may not tell you which foods are high in sodium. For example, you may not think a bagel tastes salty, but a 4-inch (10-centimeter) oat-bran bagel has 451 mg of sodium.
So how do you identify foods high in sodium? The best way to determine sodium content is to read food labels. The Nutrition Facts label tells you how much sodium is in each serving. It also lists whether salt or sodium-containing compounds are ingredients. Examples of these compounds include:
  • Monosodium glutamate (MSG)
  • Baking soda
  • Baking powder
  • Disodium phosphate
  • Sodium alginate
  • Sodium nitrate or nitrite

How to cut sodium

You may or may not be particularly sensitive to the effects of sodium. And because there's no way to know who might develop high blood pressure as a result of a high-sodium diet, choose and prepare foods with less sodium.
You can cut sodium several ways:
  • Eat more fresh foods and fewer processed foods. Most fresh fruits and vegetables are naturally low in sodium. Also, fresh meat is lower in sodium than luncheon meat, bacon, hot dogs, sausage and ham are. Buy fresh and frozen poultry or meat that hasn't been injected with a sodium-containing solution. Look on the label or ask your butcher.
  • Opt for low-sodium products. If you do buy processed foods, select those that have reduced sodium.
  • Remove salt from recipes whenever possible. You can leave out the salt in many recipes, including casseroles, stews and other main dishes. Baked goods are an exception. Leaving out the salt could affect the quality as well as the taste of the food.
  • Limit your use of sodium-laden condiments. Salad dressings, sauces, dips, ketchup, mustard and relish all contain sodium.
  • Use herbs, spices and other flavorings to enhance foods. Learn how to use fresh or dried herbs, spices, zest from citrus fruit, and fruit juices to jazz up your meals.
  • Use salt substitutes wisely. Some salt substitutes or light salts contain a mixture of table salt (sodium chloride) and other compounds. To achieve that familiar salty taste, you may use too much of the substitute and actually not use less sodium. In addition, many salt substitutes contain potassium chloride. Though dietary potassium can lessen some of the harm of excess sodium, too much supplemental potassium can be harmful if you have kidney problems or if you're taking medications for congestive heart failure or high blood pressure that cause potassium retention.
Your taste for salt is acquired, so it's reversible. To unlearn this salty savoring, decrease your use of salt gradually and your taste buds will adjust. Most people find that after a few weeks of cutting salt, they no longer miss it. Start by using no more than 1/4 teaspoon (1 milliliter) of added salt daily, and then gradually reduce to no salt add-ons. As you use less salt, your preference for it lessens, allowing you to enjoy the taste of food itself.