Salt is a mineral essential to the body’s ability to function properly. Although salt and sodium are often referred to interchangeably, table salt (sodium chloride) is actually 40 percent sodium and 60 percent chloride. Salt can have both positive and negative impacts on a person’s health.

Sodium is a mineral that occurs naturally in food. It is essential to life because it regulates the fluid balance of cells and plasma. Too little sodium in the body can result in dehydration because the cells are unable to retain water. Proper fluid balance is important to nutrition because it helps move nutrients into the cells and carries waste products out of the cells.

The kidneys regulate levels of sodium in the body. However, a person with damaged kidneys or other medical conditions (including congestive heart failure and cirrhosis) may not be able to eliminate excess sodium, allowing it to build up in the blood. Too much salt can lead to water retention in the blood, which eventually leads to high blood pressure. In addition, certain people have a greater sensitivity to sodium that may cause a spike in blood pressure when they consume too much.

Most salt and sodium intake comes from three sources: processed and prepared foods, condiments that contain sodium (including table salt and seasoned salts) and natural sources of sodium. The amount of sodium and salt found in the diet is particularly high in processed foods.

Salt is a mineral essential to the body’s ability to function properly. It is important to have a proper balance of salt in one’s diet. Although people often refer to salt and sodium interchangeably, table salt (sodium chloride) is 40 percent sodium and 60 percent chloride.                    

The mineral sodium occurs naturally in food. It is essential because of its role in regulating the fluid balance of cells and plasma. Salt regulates both blood pressure and blood volume. Too little sodium in the body can result in dehydration because the cells are unable to retain water. Proper fluid balance is important to nutrition because it move nutrients into the cells and carries waste products out of the cells. Sodium also helps regulate nerve and muscle function.

Sodium belongs to a group of minerals called electrolytes, which also includes chloride and potassium. These minerals help transmit electrical currents in the body, which is vital to transmitting nerve impulses and helping muscles (include the heart muscle) to relax or contract.

Throughout history, salt has played a role in people’s diets. For centuries before the advent of refrigeration, salt was used to preserve foods such as meat, fish, vegetables and fruit. Salt can help protect foods from bacteria, yeast and molds, preventing food spoilage and foodborne illness. At one time, salt was so highly valued that it was used as currency.

Beginning in the late 1700s, people began to prefer less salty food and other methods of food preservation became available, including canning, the use of ice in cold climates, and by the 20^th century, freezing and refrigeration. Eventually, salt was used more for industrial purposes than in preserving the food supply. However, it is still used as a preservative in cured foods (ham, sausage, bacon and corned beef) and vegetables such as pickles (which are preserved in a salt/water combination known as brine). Sodium commonly occurs as ann ingredient in many processed and frozen foods.

Other roles that salt plays in food include:

• Affects texture. For example, yeast (leavened) breads with salt have a finer texture than those without salt.
  
  
• Controls fermentation speed. Fermentation is a process that changes the chemistry of a food, altering its appearance and flavor. Salt helps control this process in cheeses, bread dough and sauerkraut.
  
  
• Increases and stabilizes volume. Salt performs this function in whipping egg whites or cream.

While moderate amounts of sodium promote good health, too much sodium may increase the risk of high blood pressure in some people. Also, overweight people who eat too much salt are at greater risk of heart disease or stroke, and people with high blood pressure are at greater risk of kidney damage.

The body only requires about half a gram of sodium per day, and the American Heart Association (AHA) recommends that people consume no more than 2.3 grams (about 1 teaspoon of salt per day). However, the average American consumes at least 9 grams of sodium per day, with many Americans eating 6 to 18 grams on a daily basis. Therefore, most Americans need to reduce their salt intake.

Recently, the American Medical Association announced an initiative to cut the nation’s sodium intake by half over the next decade.  The plan is to reduce salt in processed foods, fast foods and restaurant meals.  As part of this effort, the AMA is urging the government to mandate warning labels on foods high in salt. The AMA also plans to petition the U.S. Food and Drug Administration to remove salt from the list of foods “generally recognized as safe.”

Previously, the National Institutes of Health announced a plan to encourage manufacturers, restaurants and consumers to reduce sodium intake by 5 percent a year over the next decade.

Dietary salt intake is such a concern worldwide that an international organization of medical experts formed World Action on Salt and Health (WASH), established in 2005. Experts from 48 different nations are part of this organization, which aims to reduce dietary salt intake among all adults to 5 grams per day.

There are many different types of salt. Most cooking recipes call for table salt, but other forms of salt may be used in some foods. Types of salt include:

• Table salt. Fine, granulated salt typically found in salt shakers and used in cooking.
  
  
• Iodized salt. Table salt with the nutrient iodine added. Consumption of iodine helps the thyroid produce hormones and prevents a thyroid gland condition called goiter. An iodine deficiency is also associated with higher risk of miscarriage.
  
  
• Lite salt. Salt that is half sodium chloride and half potassium chloride. This reduces but does not eliminate a person’s salt intake.
  
  
• Salt substitute. Usually made of potassium chloride, it contains no sodium and is often used by people on sodium-restricted diets. However, salt substitutes may not be a good choice for people with kidney problems or other conditions that prohibit them from consuming too much potassium.
  
  
• Seasoned salt. Salt with herbs and other ingredients that add to flavoring. These may include celery seed, garlic powder or onion flakes. It may have less sodium than table salt.
  
  
• Popcorn salt. Finely granulated salt that sticks well to popcorn, fries and chips.
  
  
• Kosher salt. Coarse grain salt that adds a crunchy texture to some foods and drinks (e.g., margaritas). Kosher salt is used to prepare food in concordance with Jewish dietary laws. Kosher salt usually has no additives.
  
  
• Sea salt. Salt produced by evaporation of seawater. Examples include Black Sea, French or Hawaiian sea salt. Trace amounts of other minerals may be present to alter the flavor. Although sea salt is marketed as an alternative to table salt, the sodium content is similar.
  
  
• Rock salt. Chunky crystals of salt used in crank-style ice cream makers. Rock salt also may be used as foundation for serving foods such as clams or oysters.
  
  
• Pickling salt. Fine-grained salt that is used to make brines (mixture of salt and water) for preserving sauerkraut and pickles.

The kidneys regulate levels of sodium in the body. When sodium levels are low, the kidneys work to conserve sodium. When sodium levels are high, excess sodium passes from the body through urine, and to a lesser extent, through perspiration.

However, a person with damaged kidneys or other conditions (including congestive heart failure and the liver disease cirrhosis) may not be able to eliminate excess sodium, allowing it to build up in the blood. Too much salt can lead to water retention in the blood, because sodium attracts and holds water.

Normally, the kidneys flush excess water from the body. However, kidneys that are not functioning properly are unable to expel the excess fluid sufficiently, leading to fluid retention. This increases the volume of blood being pumped through the blood vessels and can lead to high blood pressure (hypertension).

In an effort to pump the extra fluid through the body, the heart may become enlarged. The extra volume of fluid may also leave the bloodstream and enter body tissues, causing swelling (edema) in the parts of the body where it builds up.

Certain people have a greater sensitivity to high levels of sodium than others. Up to 30 percent of Americans have blood pressure that is sensitive to sodium, according to the American Dietetic Association. Patients with this condition may experience a spike in blood pressure after consuming too much sodium. Research has shown that African Americans tend to be more salt-sensitive than white Americans.

Studies have not identified whether people are genetically predisposed to be salt-sensitive. However, it is known that reducing sodium consumption can help lower blood pressure in salt-sensitive patients. There is no test to indicate whether or not a person’s blood pressure is sodium-sensitive. Therefore, some patients with high-sodium diets will develop high blood pressure, while others will not.

The National Heart, Lung and Blood Institute (NHLBI) released clinical practice guidelines for the prevention, detection and treatment of high blood pressure in 2003. The report recommends and encourages lifestyle changes to prevent high blood pressure. These include losing excess weight, becoming physically active, limiting alcoholic beverages and following a heart-healthy diet, including cutting back on salt and other forms of sodium.

The guidelines recommend that people follow the Dietary Approach to Stop Hypertension (DASH) eating plan, which is rich in fruits, vegetables, lowfat dairy products and low in saturated fat, total fat, and cholesterol. It is also high in fiber. In addition to reducing levels of salt and sodium, the DASH diet includes generous helpings of other minerals that also may help lower blood pressure. This includes potassium from fruits and vegetables, calcium from dairy foods and certain vegetables and magnesium from whole grains, legumes, nuts and green vegetables.

Other studies have suggested that lower salt intake may reduce the risk of high blood pressure, heart disease, heart failure and stroke in overweight men and women. Research indicates that lower levels of salt may help reduce calcium loss from bone, which in turn reduces the risk of osteoporosis and bone fractures. In addition, reducing sodium may help a person lose weight. Sodium both attracts and holds water. People who eat less salt retain less water and are not as bloated.

One recent study even linked salt intake and obesity. Researchers reported that consuming higher levels of sodium increases thirst. Many Americans slake their thirst by drinking beverages high in calories, which in turn causes weight gain.

Although a low-salt diet benefits the health of most people, pregnant women should not cut back on sodium. Pregnant women generally need more sodium then women who are not pregnant, although this usually can be obtained in a balanced prepregnancy eating plan.

Americans get most of their salt and sodium intake from three sources: processed and prepared foods, condiments that contain sodium, and natural sources of sodium.

Sodium naturally occurs in foods such as fruits, vegetables, meat, poultry, dairy products and drinking water. Condiments such as table salt and soy sauce also add sodium to a meal, whether the condiment is added during food preparation or during eating.

However, the greatest source of sodium in the average person’s diet is processed and prepared foods. Canned vegetables, soups, luncheon meats and frozen foods all contain varying levels of salt and sodium. Salt sometimes is added to processed foods to help preserve them. The salt draws water out of the food, depriving bacteria of the moisture necessary to thrive. Salt also kills bacteria that cause food to spoil.

Salt also may be added to processed foods for other reasons including:

• Adding flavor to food
  
  
• Boosting the thickness of soups
  
  
• Decreasing dryness in foods such as crackers and pretzels
  
  
• Disguising metallic or chemical aftertastes in products such as soft drinks
  
  
• Increasing sweetness in products such as cakes, cookies and soft drinks

The amount of sodium and salt is particularly high in processed foods. Ingredients that include sodium usually can be identified for looking for several words in the ingredient list. These include “na” (the chemical symbol for sodium), “salt,” “soda” or “sodium.” Ingredients with sodium and their functions are as follows:

Sodium compounds are also found in over-the-counter medications. These include:

About 75 percent of all salt consumed in the United States comes from salt added in the processing and manufacturing of foods rather than from a salt shaker. The average American consumes 6 to 18 grams of salt daily, according to the American Heart Association (AHA). Each gram equals 1,000 milligrams of salt.

Because the body only requires about 500 milligrams per day, the sodium levels that naturally occur in fruits, vegetables, natural cheeses, sea fish and shellfish may be enough to sustain good body function. The 2005 Dietary Guidelines and the American Heart Association (AHA) recommend restricting daily sodium (salt) intake to 2,300 milligrams (2.3 grams) or less, or no more than about a teaspoon of table salt.

A person’s sodium intake quickly adds up when salt is added during the following:

• Cooking
  
  
• Adding salt to a food while eating
  
  
• In restaurant foods
  
  
• In processed, prepackaged or prepared foods purchased in the grocery store (e.g., soups, chips, cereal, pizza, lunch meats, cheese and ice cream)
  
  
• As a natural preservative for meats and vegetables

A preference for salty taste is something that people acquire, usually during childhood. People enjoy the saltiness of a food rather than the sodium, and that salty flavor is probably associated with chloride more than sodium. Usually, people who begin to eat less salt find that the desire for salt adjusts downward.

The following suggestions are offered as strategies for reducing sodium intake:

• Avoid processed foods as much as possible, or read food labels and look for reduced-sodium varieties of favorite foods. Prepared foods that tend to be high in sodium include frozen dinners, pizza, packaged mixes, canned soups or broths, and salad dressings. The following information, sanctioned by the Food and Drug Administration (FDA), on store packaging serves as a guide in reading labels:
  
• • “Sodium-free” or “salt-free” foods contain less than 5 milligrams sodium per labeled serving.
    
    
  • “Very low sodium” foods contain less than 35 milligrams sodium per serving.
    
    
  • “Low-sodium” foods contain 140 milligrams or less sodium per serving.
    
    
  • "Light in sodium" foods contain at least 50 percent less sodium per serving than an average reference food without any sodium reduction.
    
    
  • "Lightly salted" foods contain at least 50 percent less sodium per serving than reference amount.
    
    
  • “Reduced-sodium” foods contain at least 25 percent less sodium per reference amount than an appropriate reference food. Some reduced-sodium products such as soy sauce or canned soups can still contain significant amounts of sodium.
    
    
  • “Unsalted” or “no salt added” must meet conditions of use and must declare “This is Not a Sodium Free Food” on information panel if food contains sodium.
    
    
• Cut back on high-sodium foods gradually. This allows a person time to grow accustomed to less salty food.
  
  
• Taste food before adding salt. In many cases, people find that food tastes fine without the added salt.
  
  
• Look at the nutrition facts section of a food label to see how much sodium is in one serving of the food. It is generally better to consume foods that contain 5 percent or less of the daily value (DV) for sodium, according to the American Dietetic Association. More than 20 percent of the DV for sodium is high.
  

  

• Take the salt shaker off the table.
  
  
• Choose meats with less naturally occurring salt, such as turkey or chicken.
  
  
• Choose foods that naturally have less sodium, including fish, dry and fresh legumes, nuts, eggs, milk, and yogurt. Other foods that have low levels of sodium include plain rice, pasta and oatmeal.
  
  
• Use seasonings and spices other than, and not containing, salt (e.g., choose garlic powder over garlic salt). Herb-spice blends are good substitutes, as are lemon and lime juices. Be sure to check the nutrition facts label to make sure these products do not contain sodium. People who still prefer a saltier taste may want to try monosodium glutamate (MSG). MSG has about one-third as much sodium as table salt.
  
  
• Replace canned, frozen and other processed foods with fresh fruits and vegetables. For example, one cup of cooked fresh peas may have just 2 milligrams of sodium while a cup of canned peas has 493 milligrams of sodium. People who purchase processed foods are urged to look for low-sodium versions.
  
  
• Rinse canned foods such as tuna to remove some sodium.
  
  
• Cook hot cereals, pasta or rice without using salt. Reduce the use of instant or flavored cereal, pasta and rice mixes, which typically have a lot of salt.
  
  
• Limit consumption of salty snacks like pretzels, peanuts and potato chips.
  
  
• Request that restaurants cook without additional salt or MSG, which is often used in commercial cooking.
  
  
• Use margarine or unsalted butter rather than regular butter.
  
  
• Select low-fat, low-sodium cheese and yogurt.
  
  
• Eat bananas and other potassium-rich foods. These foods help to balance sodium levels.
  
  
• Look for low-sodium over-the-counter medications.

People who are seeking to lower dietary sodium are urged to consider the following:

Because a small amount of sodium is vital for maintaining healthy body function, it is possible to have too little salt. Symptoms of sodium deficiency include weakness, cramping, headache, nausea, fatigue, dizziness, loss of appetite, and (in severe cases) shock. However, this condition is rarely experienced by anyone other than athletes who have been sweating profusely for long periods of time, or people who regularly use diuretics or laxatives. Even strenuous activity is usually not enough to lower a person’s sodium content to unhealthy levels, because any lost electrolytes are easily restored through normal meals and snacks.

Preparing questions in advance can help patients have more meaningful discussions regarding their conditions. Patients may wish to ask their doctor or registered dietitian the following questions related to salt:

1. Should I be monitored for high blood pressure if I have a family history of sodium-sensitive blood pressure?
   
   
2. Can you explain the difference between salt and sodium?
   
   
3. Do you suspect a medical condition is at the root of my high blood pressure?
   
   
4. Do I still need to worry about watching my salt intake if I am taking blood pressure medicine?
   
   
5. How will I know how much salt is in my food when I dine out?
   
   
6. Can you recommend restaurants that serve low-sodium foods?
   
   
7. If I am not overweight but have high blood pressure, is salt restriction still important?
   
   
8. Should I visit a dietician? Can you recommend one?
   
   
9. Can you recommend medications that are low in sodium?
   
   
10. Are there any symptoms that will indicate I am getting too much salt?