Sodium is an important mineral and electrolyte necessary for many functions in the body. It has an important role in maintaining water balance within cells, and is involved in proper functioning of both nerve impulses and muscles within the body. Along with potassium, sodium also plays a crucial role in blood pressure regulation. Sodium is only needed in small quantities, and the kidneys are responsible for excreting extra sodium from the body.
Sources of sodium
Sodium in Food—A small amount of sodium is naturally present in most foods, but most dietary sodium is found in processed foods in the form of salt. Salt may be added for flavor enhancement and to extend the shelf life of certain foods. Salt is added to most canned foods, some frozen vegetables, fast foods, smoked and cured meats, and pickled foods (Table 1). It is used in most cheeses, sauces, soups, salad dressings and many breakfast cereals. It is also found in many other ingredients used in food processing. Many commercially prepared condiments and seasonings are also high in sodium. The food industry is working to decrease sodium content in these food items.
Sodium in Salt—Sodium is a component of salt. Table salt, also known as sodium chloride, is 40% sodium and 60% chloride. The sodium portion of salt is associated with high blood pressure.
How much sodium?
The Adequate Intake (AI) for sodium is 1,500 milligrams daily for males and females ages 9-50. This value is less than 1 teaspoon of table salt per day. The maximum recommended level of sodium intake is 2,300 milligrams daily.
On average, more than 85 percent of American men and women consume sodium in amounts that far exceed the maximum recommended level of intake.
Sodium deficiency is extremely rare, as most Americans over-consume sodium. Deficiency usually only occurs with prolonged bouts of fluid loss due to diarrhea, vomiting, or perspiration. Those who have kidney problems may also be more likely to develop a sodium deficiency. Symptoms of deficiency include nausea, dizziness, and muscle cramps.
For athletes and those strenuously active for more than 1 hour in duration—Those exposed to conditions promoting sweat loss for extended periods may be at risk for low blood sodium levels. For those who are well hydrated and active for more than four hours, it is important to replenish sodium stores in the body.
Usually, sodium losses can be easily replaced during the next meal. However, in endurance exercise longer than 4 hours, sodium stores should be replaced during exercise with food or sports drink
Too much sodium?
Most Americans consume too much sodium. The Tolerable Upper Limit Level (UL) for sodium is 2,300 milligrams daily for teens and adults. This value does not apply to those with high blood pressure, as this value may be set too high. In healthy individuals, excess sodium is usually excreted by the kidneys. However, chronic consumption of excess sodium may also lead to edema or water retention.
Special Conditions for a Low Sodium Diet—In addition to those who are African American or over the age of 51, groups with the following conditions should limit sodium intake to 1,500 milligrams daily:
Kidney Disease: Those with kidney disease may have trouble excreting sodium and other minerals, leading to water retention and swelling.
Congestive Heart Failure: Those with heart failure experience swelling and fluid retention in the lungs and throughout the body. Since sodium promotes fluid retention, a low sodium diet may be helpful in relieving fluid accumulation.
Osteoporosis: Women who consume excess sodium may be at higher risk for developing osteoporosis even if calcium intake is adequate. Some evidence suggests that for each teaspoon of salt (2,000 milligrams of sodium) consumed, considerable calcium is excreted in the urine.
High Blood Pressure or Hypertension: High sodium consumption is one factor involved in the development of high blood pressure, or hypertension. Hypertension tends to develop as people age, and can lead to cardiovascular disease. Some individuals are “salt sensitive,” so reducing intake of sodium helps to reduce blood pressure levels. A high intake of sodium early in life might weaken genetic defenses against developing high blood pressure. Experts recommend reducing sodium intake while blood pressure is still normal, which may decrease the risk for hypertension later in life.
For those with hypertension or any other special condition, following an overall eating plan known as DASH (Dietary Approaches to Stop Hypertension) and restricting sodium intake to 1,500 milligrams per day, may be useful for lowering blood pressure. Increasing potassium intake has also been shown to have beneficial effects for lowering blood pressure.
Steps to reduce sodium
An important recommendation from the Dietary Guidelines for Americans is to reduce consumption of sodium. The following suggestions are starting points to reduce dietary sodium:
— Use more fresh fruit, vegetables and meat. Processed foods usually contain more sodium.
— When cooking use canola oil or olive oil, which contain less sodium, instead of butter or margarine.
— Check food labels for the words salt or sodium. Salt often is used as a preservative or flavoring agent. Any ingredient that has sodium, salt or soda as part of its name (monosodium glutamate (MSG), baking soda, and seasoned salt) contains sodium. Do not use salt substitutes, especially those that contain potassium, without first talking to a medical professional.
— Remove the salt shaker from the table and season foods with herbs and spices rather than salt.
— Try products such as low or reduced sodium to curb sodium intake.
— Plan meals that contain less sodium. Try new recipes that use less salt and sodium-containing ingredients and seasonings. Adjust your own recipes by reducing such ingredients a little at a time. Make homemade condiments, dressings and sauces that are low in sodium.
— Taste food before it is salted. If using canned food, rinse in water to remove some of the salt before preparing or serving.
Source: Colorado Cooperative Extension
Fruity Rainbow Salad
1 can (8 ounces) unsweetened pineapple chunks
2 cups sliced fresh strawberries
2 cups green grapes
1 can (15 ounces) mandarin oranges, drained
¼ cup lemon juice
¼ cup honey
1/8 teaspoon nutmeg
Drain pineapple, reserving ¼ cup juice. In a bowl, combine the fruit. In another bowl, combine the lemon juice, honey, nutmeg and reserved pineapple juice. Pour over fruit. Mix gently. Cover and refrigerate for several hours or overnight. Serves 8.
Sandra R. Cain is the Extension agent for Family and Consumer Sciences in Bladen County.