Educational Series
The Science of Nutrition
Is Salt Good For You?
By Mohammad Ahrar, PhD
Introduction
Historically, salt has played a major role in people’s lives. According to the Oxford English Dictionary, ancient civilizations traded salt for gold, ounce-for-ounce. The Greeks and Romans bought slaves with salt, and cakes of salt were used as money. A salt tax ignited the French Revolution. History also shows that as humans craved salt, they followed animals to find a source of salt, and tribes migrated from place to place in search of water and salt.
What Is Salt Made Of?
In chemistry, salt has a broad explanation, basically referring to the combination of positively and negatively charged compounds. For this article, we are just referring to table salt. Salt is also known as sodium chloride (NaCl), which consists of about 40% sodium (Na+) and 60% chloride (Cl–). Salt is commonly harvested from salt mines or by evaporating ocean water or salt lakes.
Role Of Salt In The Body
The human body requires a small amount of sodium to conduct nerve impulses, contract and relax muscles, and to maintain the proper balance of water and minerals. The body of a 154-pound adult contains about 105 grams (3.5 ounces) of sodium. Approximately 70 percent of the sodium in the body is in the blood, other extracellular fluids, and also in nerves and muscle tissue. The other 30 percent is in bones. When you eat foods that contain salt, about 95 percent of ingested sodium is absorbed into the bloodstream. To maintain a normal level of sodium in the blood, the kidney either reabsorbs sodium and returns it to the bloodstream or allows it to be spilled in the urine. Some hormones are involved in these processes.
Sodium is necessary for the transmission of electrochemical impulses along nerve and muscle membranes. The influx of sodium from the extracellular fluid (surrounding the cells) into the nerve cells produces an electrochemical impulse or nerve signal that can stimulate body muscles to function, heart muscles to beat, and smooth muscles surrounding the blood vessels and intestinal walls to function properly. Without sodium, nerves and muscles cannot function, which would result in paralysis.
How Much Salt Do You Need?
The human body requires a small amount of sodium to maintain the proper balance of water and minerals as well as the proper functions of the body’s organs and tissues. It is estimated that we need about 500 mg of sodium daily for these vital functions. The American Heart Association advises adults to get no more than 2,400 milligrams of sodium daily. That’s about 1 teaspoon of salt per day. The Dietary Guidelines for Americans, which is published by the U.S. Department of Agriculture in conjunction with the U.S. Department of Health and Human Services, recommends limiting sodium to even less than 2,300 milligrams a day. Please be reminded that almost all foods that you eat contain salt, which makes the total consumption of salt likely more than the recommended level.
Food Sources
Almost all unprocessed foods like fruits, vegetables, whole grains, raw nuts, raw meats, and dairy items contain a low amount of sodium. Most of the salt in our diets comes from commercially-prepared foods. Salt is used as a binder and stabilizer in most commercial foods. It is also a food preservative, as bacteria can’t thrive in the presence of a high amount of salt.
According to The Centers for Disease Control and Prevention (CDC), the top 10 sources of sodium in our diets include bread/rolls; pizza; sandwiches; cold cuts/cured meats; soups; burritos, tacos; savory snacks (chips, popcorn, pretzels, crackers); chicken; cheese; eggs, omelets, and most preserved foods. Studies also indicate that ketchup, mustard, salad dressings, pickled foods, sausage, bacon, ham, salty snack foods, monosodium glutamate (MSG, which is often added to Chinese food), soy sauce, processed meat, and other processed foods are high in sodium and low in potassium.
Types Of Salt
Finely ground salts are dense, so they tend to contain more sodium than coarser salts.
∙ Iodized table salt, fine – contains about 2,300 mg of sodium per teaspoon
∙ Sea salt, fine – about 2,120 mg/teaspoon
∙ Sea salt, course – about 1,560 mg/ teaspoon
∙ Kosher salt, course – about 1,920 mg/teaspoon
∙ Pink (Himalayan) salt – about 2,200 mg/teaspoon
The inclusion of brand names on this list is for reference only and does not constitute an endorsement for any specific brands. Note that sodium content can vary widely among brands, so check the Nutrition Facts label for exact amounts.
According to the Mayo Clinic, the main differences between sea salt and table salt are in their taste, texture, and processing. Table salt is typically mined from underground deposits. It is processed to remove other minerals. Table salt is commonly fortified with iodine, which is important for thyroid health. Sea salt is a general term for salt produced by the evaporation of ocean water or water from saltwater lakes. It is less processed than table salt and retains trace minerals which add flavor and color. Sea salt is often promoted as being healthier than regular table salt. However, no significant differences in nutritional value have been found between the two. Himalayan pink salt is sourced near the Himalayan mountains of South Asia and from mines in Pakistan. Its pink hue comes from small amounts of iron oxide. Course Himalayan pink salt may contain less sodium per serving than ordinary table salt. It also contains some trace minerals such as zinc, iron, calcium, potassium, and magnesium depending on where the Himalayan pink salt is sourced. Although Himalayan salt is believed to be a healthier alternative to common table salt, scientists don’t believe that the small amount of additional minerals in Himalayan pink salt is great enough to make a significant difference in your diet.
What Happens If Salt Is Eliminated From The Diet?
A deficiency of sodium in the U.S. is rare because it is so commonly added to a wide variety of foods and occurs naturally in some foods. Elimination of salt from the diet over a long period of time can result in hyponatremia, a condition that occurs when the sodium in your blood falls below the normal range of 135–145 mEq/L. Excess vomiting, diarrhea, and sweating can also cause hyponatremia. In rare cases, simply drinking too much fluid can lead to hyponatremia if the kidneys cannot excrete the excess water. In severe cases, low sodium levels in the body can lead to muscle cramps, nausea, vomiting, dizziness, headaches, altered mental state/confusion, lethargy, seizures, and coma. Total elimination of salt can lead to shock, coma, and even death.
What Is Problematic About Consuming Too Much Salt?
Too much sodium in the blood is called hypernatremia. Medical studies have shown that long-term excess of sodium intake can lead to high blood pressure, heart disease, and stroke. It can also cause calcium losses, some of which may be pulled from the bone.
According to The Dietary Guidelines for Americans, salt intake should be no more than 2,400 milligrams a day. Most Americans consume at least 1.5 teaspoons of salt per day, far more than our bodies need. Studies show that the kidneys have trouble keeping up with excess sodium in the blood. As sodium accumulates, the body holds onto water to dilute the sodium. This increases both the amount of fluid surrounding cells and the volume of blood in the bloodstream. Increased blood volume means more work for the heart and more pressure on blood vessels. Over time, the extra work and pressure can stiffen blood vessels, leading to high blood pressure, heart attack, stroke, and damage to the kidneys. This fluid shift and a build-up of fluid in the brain can cause seizures, coma, or even death. Extra fluid collecting in the lungs can also cause difficulty breathing.
Some studies have shown that there may be a genetic component to salt intake, as people respond differently to lower sodium intakes. Those who are “salt-sensitive” experience the greatest blood pressure reductions after following a reduced sodium diet. Those who are “salt-resistant” do not experience these changes even with significant increases in sodium intake.
The Interplay Of Sodium And Potassium
Sodium and potassium are closely interconnected but have opposite effects on the body. High salt intake increases blood pressure, which can lead to heart disease, while high potassium intake to a certain level can help relax blood vessels and excrete sodium, decreasing blood pressure. Studies indicate that the higher the ratio of potassium to sodium in a participant’s diet, the lower the chances of developing cardiovascular trouble. This suggests that a strategy that includes both increasing potassium in the diet such as eating more fruits, vegetables, legumes, bananas, and low-fat dairy products while lowering sodium to a certain level may be the most effective way to fight high blood pressure. Vegetables and fruits are naturally high in potassium and low in sodium. A study in the Archives of Internal Medicine found that people with the highest ratio of sodium to potassium in their diets had double the risk of dying of a heart attack than people with the lowest ratio.
Start Early To Prevent A Craving For Salt
Studies from Harvard University indicate that high blood pressure can start developing in childhood and becoming conditioned to high-salt tastes early in life can make it more difficult to cut back later. Childhood is an important time to focus on preventing the development of high blood pressure, but cutting back on salt and sodium can have a significant impact on people of all ages. About 70% of the sodium Americans eat comes from processed, prepared foods such as crackers, cheese, canned foods, and restaurant meals. Even processed foods that don’t taste “salty”—like breakfast cereal—can have surprisingly high sodium levels. Additionally, foods consumed numerous times a day, such as bread, can add up to a higher sodium intake even though an individual serving is not high in sodium.
Choosing foods with lower sodium doesn’t mean losing flavor. Human taste buds aren’t sensitive enough to notice a minor reduction in the salt of about 30%, and for many types of foods, salt reductions of up to 30% won’t taste noticeably different. This means that home cooks, professional chefs, and the food industry can make significant sodium reductions with minimal impact on flavor.
Smaller Portions Matter
There’s no need to completely eliminate favorite foods or traditional cultural cuisines. Instead, it’s best to enjoy such foods in smaller amounts. However, in foods where salt is a key component, such as soy sauce or cold cuts, the best a manufacturer can do is reduce the amount. Whichever type of salt you enjoy, do so in moderation.
Salt Alternatives
Salt substitutes, including herbs, spices, and citrus such as lemon can provide more flavor with less sodium. For example, citrus and sodium both activate the same taste sensors; therefore, less sodium can be used when combined with citrus. The Food and Drug Administration (FDA) requires a “low-sodium” labeled food to contain less than 140 mg per serving.
Summary
Salt is known as sodium chloride (NaCl) consisting about 40% sodium (Na+) and 60% chloride (Cl–). Salt is commonly harvested from salt mines or by evaporating ocean water or salt lakes. Sodium is necessary for the transmission of nerve impulses or signals that can stimulate body muscles to function, heart muscles to beat, and smooth muscles to function properly. The Dietary Guidelines for Americans recommends limiting consumption of salt to no more than 2,400 milligrams per day.
References
