Everyone likes to talk about the good ol’ days, and in food circles, we hark back to ancestral diets that were more natural and more nutritious. However, in one respect, modern people enjoy a huge advantage over their ancestors: Everybody in the world today has access to plentiful, inexpensive salt.
An interesting article on the social history of salt, published in a 1963 Scientific American issue, notes that in ancient times, where salt was plentiful, the society tended to be free, independent, and democratic; where it was scarce, those who controlled the salt controlled the people. For example, along the shores of the Mediterranean and the North Sea, farmers and fishermen with access to plentiful salt enjoyed free societies. By contrast, areas of the world that had to import most of their salt or obtain it from small, isolated sources show a more autocratic pattern, a history of frequent conflict, monopoly, and all-powerful rulers. In the ancient river valley civilizations of the Nile, Babylon, India, China, Mexico, and Peru, the kings and priests maintained their rule and obtained their income through their monopoly of salt, on which the population depended for their survival.
The colonization of India provides a modern example. The British exerted control by heavily taxing salt and jailed those Indians who dared to make salt themselves. In protest, Gandhi led a salt march that gained worldwide attention. “Next to air and water, salt is perhaps the greatest necessity of life,” he said, believing a mass protest over the salt laws would help invigorate the cause of Indian independence.
It’s estimated that the British arrested 60,000 people, including Gandhi himself, during this Indian version of the Boston Tea Party, but eventually the colonizers signed a pact that led to the release of political prisoners and allowed the manufacturing of salt by Indians in coastal areas. Indian independence followed a few years later.
The fact is, we cannot live without salt. Salt is our main source of sodium and chloride, both essential minerals. While small amounts of sodium and chloride are present in a variety of foods, our main source of these two essential minerals is salt.
One of salt’s major functions is to regulate blood volume and pressure, including the flexibility of the blood vessels. For certain individuals who are salt sensitive, excessive consumption of sodium can increase blood pressure, but for the majority, blood pressure is not raised by increased salt intake.
In fact, some people experience an increase in blood pressure when they reduce salt intake. In most people, even a drastic increase in salt consumption does not raise blood pressure.
When our salt consumption is too low, defense mechanisms kick in; these include salt hunger to increase sodium intake and reduction of urine and sweat to reduce sodium losses. When salt intake is too high, salt receptors in the tongue make the salt taste unpleasant, which tends to decrease the intake of salty foods.
Salt plays a key role in digestion. Sodium-dependent enzymes are required for carbohydrate digestion, to break down complex carbohydrates and sugars into monosaccharides such as glucose, fructose, and galactose; sodium is also involved in transporting these monosaccharides across the intestinal wall.
The chloride in salt is the major component of hydrochloric acid, needed for protein digestion. Hydrochloric acid also plays a role in keeping parasites and pathogens from entering the digestive tract—parasites can easily gain a foothold in those on low-salt diets. Other symptoms of hypochlorhydria (low hydrochloric acid) include bloating, acne, iron deficiency, belching, indigestion, diarrhea, and multiple food allergies.
In addition to carbohydrate and protein digestion, fat digestion also requires salt. Sodium is involved in the manufacture of bile, which emulsifies fats so that they can be absorbed.
We need salt for our brains. Chloride is essential for the growth of the brain and the development of neurological function, and sodium activates enzymes needed for the development and function of glial cells in the brain. Unfortunately, many so-called experts advise pregnant and nursing mothers to adopt a low-salt diet, or to restrict salt in the diets of their infants. Mental confusion is a common side effect of a low-salt diet.
The adrenal glands are responsible for the release and regulation of more than 30 of the body’s hormones, including sex hormones and hormones that regulate blood pressure, glucose levels, mineral metabolism, healing, and stress response. They produce the body’s supply of epinephrine and norepinephrine, which help regulate metabolism. Adequate salt helps the adrenal glands to produce the hormones needed to keep the body’s metabolism running smoothly; for example, vitamin C transport into the adrenal glands is sodium-dependent, and vitamin C is an enzymatic cofactor involved in the production of several adrenal hormones. Craving salt is a sign of poor adrenal function.
When levels of aldosterone drop, which often happens during periods of stress or fatigue, the body responds by craving salt to help stabilize blood pressure. If the adrenal glands are working hard to produce aldosterone in situations of salt deprivation, they may not be able to produce other important hormones, including stress and sex hormones.
The medical literature has repeatedly linked low-salt diets with conditions like insulin resistance (diabetes), metabolic syndrome, increased cardiovascular mortality and readmissions, cognition loss in babies and older adults, and unsteadiness, falls, and fractures.
How Much Salt?
Americans consume an average of 1.5 teaspoons (8 grams) of salt per day, which satisfies the requirement for sodium and chloride for most people. However, many need more salt and thrive on twice that amount
Surprisingly, available data suggest that Western societies consumed between 3 and 3.3 teaspoons (15–17 grams) of salt per day from the early 1800s until the end of World War II, based on military archives for prisoner-of-war and soldier rations around the world. Of course, much of that salt was for preserving meat and fish, so it had a much wider role in food preservation at that time.
During the War of 1812, despite its high cost, salt rations amounted to three teaspoons (15 grams) per day. American prisoners of war, incarcerated in Britain’s Dartmoor prison, bitterly complained that the little over 2 teaspoons of salt per day they received were part of a “scanty and meager diet for men brought up in the land of liberty, and ever used to feast on the luscious fruits of plenty.”
After World War II, with the advent of refrigeration rather than salt as a means of preserving food, salt consumption in the United States dropped dramatically to about half that rate and has remained flat for the last 50 years. During that time, rates of hypertension have increased, thus casting doubt on any linkage between salt consumption and blood pressure levels.
In a 2011 study, published in the Journal of the American Medical Association, researchers found moderate salt intake to be associated with the lowest risk of cardiovascular events, whereas low intakes, equivalent to less than or equal to 1.5 teaspoons (8 grams, of which contains 3.5 grams of sodium) of salt per day, were associated with an increased risk of cardiovascular death and hospitalization for congestive heart failure. Higher intakes of more than 3 teaspoons (7 grams of sodium) of salt per day were associated with an increased risk of stroke, heart attack, and other cardiovascular events.
Despite what we know about the importance of adequate salt in the diet, on June 1, 2016, U.S. health officials announced a new set of recommendations regarding the salt content of processed foods. The stated goal was to help Americans reduce sodium intake to levels recommended by the Institute of Medicine (IOM) in 2004 and 2005, to less than 1 teaspoon—for everyone, including growing children and frail elders. The maximum recommended was set at slightly more than 1 teaspoon.
Ironically, about the same time that U.S. health officials announced their new initiative to reduce salt intake, The Lancet published a large population-based study that showed that the risk of mortality and serious cardiovascular events increases significantly when salt intake drops below ⅔ teaspoon in an adult of average weight.
The good news is that we are all free to ignore the U.S. guidelines and enjoy salt on our food. The bad news is that most salt in the food supply is refined, a process that removes all the magnesium and trace minerals and often adds anti-caking agents such as sodium ferrocyanide, ammonium citrate, and aluminum silicate. Fortunately, many brands of unrefined salt are now available; choose salt that is light gray, pink, or beige (not bright white), indicating the presence of minerals.
One last caveat: To meet government recommendations of reduced salt in processed food, manufacturers are adding flavor enhancers that mimic the taste of salt. Developed by a biotech company named Senomyx, the products are labeled as “artificial flavors.” They are now added to most processed food, including soft drinks and juices, snack foods, cereals, cookies, soups, and mixes. Their health effects are unknown, but one consequence is likely to be increased obesity, as consumers of processed food just eat and eat and eat to satisfy the cravings brought on by additives and nutrient deficiencies.