Function
The body uses sodium to control blood pressure and blood volume. Sodium is also needed for your muscles and nerves to work properly.
Food Sources:
Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which is table salt. Milk, beets, and celery also naturally contain sodium, as does drinking water, although the amount varies depending on the source.
Sodium is also added to various food products. Some of these added forms are monosodium glutamate, sodium nitrite, sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate. These found in items such as Worcestershire sauce, soy sauce, onion salt, garlic salt, and bouillon cubes.
Processed meats, such as bacon, sausage, and ham, and canned soups and vegetables are all examples of foods that contain added sodium. Fast foods are generally very high in sodium.
Side Effects
Too much sodium in the diet may lead to:
High blood pressure in some people
A serious build-up of fluid in people with congestive heart failure, cirrhosis, or kidney disease
Recommendations:
Sodium in the diet (called dietary sodium) is measured in milligrams (mg). Table salt is 40% sodium; 1 teaspoon of table salt contains 2,300 mg of sodium.
Healthy adults should limit sodium intake to 2,300 mg per day. Adults with high blood pressure should have no more than 1,500 mg per day. Those with congestive heart failure, liver cirrhosis, and kidney disease may need much lower amounts.
The specific amount of sodium intake recommended for infants, children, and adolescents is not clear. Eating habits and attitudes about food formed during childhood are likely to influence eating habits for life. For this reason, it is a good idea to avoid eating too much salt.
Sodium: Essential in small amounts
Your body needs some sodium to function properly because it:
Helps maintain the right balance of fluids in your body
Helps transmit nerve impulses
Influences the contraction and relaxation of muscles
Your kidneys naturally balance the amount of sodium stored in your body for optimal health. When your body sodium is low, your kidneys essentially hold on to the sodium. When body sodium is high, your kidneys excrete the excess in urine.
But if for some reason your kidneys can't eliminate enough sodium, the sodium starts to build up in your blood. Because sodium attracts and holds water, your blood volume increases, which makes your heart work harder and increases pressure in your arteries. Such diseases as congestive heart failure, cirrhosis and chronic kidney disease can make it hard for your kidneys to keep sodium levels balanced.
Some people's bodies are more sensitive to the effects of sodium than are others. If you're sodium sensitive, you retain sodium more easily, leading to fluid retention and increased blood pressure. If this becomes chronic, it can lead to heart disease, stroke, kidney disease and congestive heart failure.
Sodium: How much do you need?
The Dietary Guidelines for Americans recommend limiting sodium to less than 2,300 mg a day — or 1,500 mg if you're age 51 or older, or if you are black, or if you have high blood pressure, diabetes or chronic kidney disease.
Keep in mind that these are upper limits, and less is usually best, especially if you're sensitive to the effects of sodium. If you aren't sure how much sodium your diet should include, talk to your doctor or dietitian.
Sodium: What are the major dietary sources?
The average American gets about 3,400 mg of sodium a day — much more than recommended. Here are the main sources of sodium in a typical diet:
Processed and prepared foods. The vast majority of sodium in the typical American diet comes from foods that are processed and prepared. These foods are typically high in salt and additives that contain sodium. Processed foods include bread, prepared dinners like pasta, meat and egg dishes, pizza, cold cuts and bacon, cheese, soups, and fast foods.
Natural sources. Some foods naturally contain sodium. These include all vegetables and dairy products, meat, and shellfish. While they don't have an abundance of sodium, eating these foods does add to your overall body sodium content. For example, 1 cup (237 milliliters) of low-fat milk has about 100 mg of sodium.
In the kitchen and at the table. Many recipes call for salt, and many people also salt their food at the table. Condiments also may contain sodium. One tablespoon (15 milliliters) of soy sauce, for example, has about 1,000 mg of sodium.
Tips for cutting back on sodium
Virtually everyone can benefit from reducing the sodium in their diet. Here are more ways you can cut back on sodium:
Eat more fresh foods. Most fresh fruits and vegetables are naturally low in sodium. Also, fresh meat is lower in sodium than are luncheon meat, bacon, hot dogs, sausage and ham. Buy fresh or 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, choose those that are labeled "low sodium." Better yet, buy plain whole-grain rice and pasta instead of ones that have added seasonings.
Remove salt from recipes whenever possible. You can leave out the salt in many recipes, including casseroles, soups, stews and other main dishes that you cook. Look for cookbooks that focus on lowering risks of high blood pressure and heart disease.
Limit use of sodium-laden condiments. Soy sauce, salad dressings, sauces, dips, ketchup, mustard and relish all contain sodium.
Use herbs, spices and other flavorings to season foods. Use fresh or dried herbs, spices, zest from citrus fruit, and fruit juices to jazz up your meals. Sea salt, however, isn't a good substitute. It has about the same amount of sodium as table salt.
Use salt substitutes wisely. Some salt substitutes or light salts contain a mixture of table salt and other compounds. To achieve that familiar salty taste, you may use too much of the substitute — and get too much sodium. Also, many salt substitutes contain potassium chloride. Although potassium can lessen some of the problems from excess sodium, too much potassium can be harmful especially if you have kidney problems or if you're taking medications for congestive heart failure or high blood pressure that cause potassium retention.
Sodium: Be a savvy shopper
Taste alone may not tell you which foods are high in sodium. For example, you may not think a bagel tastes salty, but a typical 4-inch (10-centimeter) oat-bran bagel has about 600 mg of sodium, and even a slice of whole-wheat bread contains about 100 mg of sodium.
So how can you tell which foods are high in sodium? Read food labels. The Nutrition Facts label found on most packaged and processed foods lists the amount of sodium in each serving. It also lists whether the ingredients include salt or sodium-containing compounds, such as:
Monosodium glutamate (MSG)
Baking soda (also called sodium bicarbonate)
Baking powder
Disodium phosphate
Sodium alginate
Sodium citrate
Sodium nitrite
Try to avoid products with more than 200 mg of sodium per serving. And be sure you know how many servings are in a package — that information is also on the Nutrition Facts label.
Sodium: More tips to cut back
The supermarket is full of foods labeled "reduced sodium" or "light in sodium." But don't assume that means they're low in sodium. For example, a can of chicken noodle soup that claims to have 25 percent less sodium still has a whopping 524 mg in 1 cup. It's only lower in salt compared with regular chicken noodle soup that has more than 790 mg of sodium in a cup.
Here's a rundown on common sodium claims and what they really mean:
Sodium-free or salt-free. Each serving in this product contains less than 5 mg of sodium.
Very low sodium. Each serving contains 35 mg of sodium or less.
Low sodium. Each serving contains 140 mg of sodium or less.
Reduced or less sodium. The product contains at least 25 percent less sodium than the regular version.
Lite or light in sodium. The sodium content has been reduced by at least 50 percent from the regular version.
Unsalted or no salt added. No salt is added during processing of a food that normally contains salt. However, some foods with these labels may still be high in sodium because some of the ingredients may be high in sodium.
Go low and take it slow
Your taste for salt is acquired, so you can learn to enjoy less. Decrease your use of salt gradually and your taste buds will adjust.
After a few weeks of cutting back on salt, you probably won't miss it, and some foods may even taste too salty. Start by using no more than 1/4 teaspoon of salt daily — at the table and in cooking. Then throw away the salt shaker. As you use less salt, your preference for it diminishes, allowing you to enjoy the taste of the food itself, with heart-healthy benefits.