Why Salt is Essential to Health and Happiness
A national program to reduce dietary salt “could prevent tens of thousands of heart attacks, strokes, and deaths and trim as much as $24 billion from the U. S. health care tab, according to a study published Wednesday in the New England Journal of Medicine.”1 So began a January 21, 2010 Wall Street Journal article on salt. “The study, a computer simulation, suggested that the impact would be similar to prevention strategies such as quitting smoking, lowering cholesterol or modest weight loss” as an “effective weapon against high blood pressure and cardiovascular disease.” According to Kirsten Bibbins-Domingo, lead author of the study, “The time is right now to consider efforts to achieve population-wide reduction in salt intake.” We have heard words like this before. In the 1970s, the McGovern Committee on Dietary Goals assured Americans that our ten greatest killers would be resolved by the simple measure of substituting polyunsaturated oils for animal fats. Now, forty years later, Americans have largely abandoned animal fats for industrial oils, with disastrous consequences—our ten greatest disease killers have only increased, and the pall of disease has now settled on our children as well. At least in the case of saturated fat we have a substitute, albeit a poor one—refined carbohydrates, which the body very efficiently turns into saturated fat. But as far as the body is concerned, there is no substitute for salt.
VITAL TO HEALTH
Salt, of course, is vital to health. There’s a reason we have a salt taste in our mouths and a reason that foods taste better with salt. The desire for salt is not some cruel joke imposed by a capricious god, but acts to ensure that we eat our food with salt.
The body’s interior ocean is salty, and without salt the myriad chemical reactions that support enzyme function, energy production, hormone production, protein transport and many other biochemical processes simply can’t work. The chemical requirements of the human body demand that the salt concentration in the blood be kept constant. If the body does not get enough salt, a hormonal mechanism compensates by reducing the excretion of salt in the urine and sweat. But it cannot reduce this output to zero. On a completely saltless diet, the body steadily loses small amounts of salt via the kidneys and sweat glands—more if the body is engaging in vigorous physical activity. It then attempts to adjust to this loss by accelerating its secretion of water, so that the blood’s salt concentration can be maintained at the vital level. The result is a gradual desiccation of the body and finally death. The organism literally dies of thirst.
Western people today consume about half the amount of salt that they consumed traditionally. Before the days of refrigeration, most of our meat and fish was preserved by salting it. The Japanese, who have one of the highest salt intakes in the world, also have the highest life expectancy.
Salt provides two elements that are essential for life and for good health: sodium and chloride ions. They are both elements that the body cannot manufacture itself so it must be supplied by food. Although salt is the most common dietary source for these essential elements, sodium is also available from various foods that contain sodium naturally.
Sodium is a mineral element that plays a critical role in body physiology. It controls the volume of fluid in the body and helps maintain the acid-base level. About 40 percent of the body’s sodium is contained in bone, some is found within other organs and cells and the remaining 55 percent is in blood plasma and extracellular fluids. Sodium is important in proper nerve conduction, in aiding the passage of various nutrients into cells, and in the maintenance of blood pressure.
Chloride ions also help maintain proper blood volume, blood pressure, and pH of body fluids. Chloride is the major extracellular anion and contributes to many body functions including the maintenance of blood pressure, acid-base balance, muscular activity, and the movement of water between fluid compartments. While sodium is present in a variety of foods, chloride is not; adequate chloride must be obtained from salt.
One of salt’s major functions is to regulate blood volume and pressure, including the flexibility of the blood vessels. Blood pressure can be affected by stress, age, exercise, heredity and diet. 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 an average population when salt intakes are reduced, about 30 percent will experience a small drop in blood pressure, between one and four mm Hg, while about 20 percent will experience a similar increase in blood pressure. The remaining 50 percent of the population will show no effect at all of salt intake reduction. In most people, even a drastic increase in salt consumption does not raise blood pressure.2
Nevertheless, the entire debate on salt and health has almost exclusively focused on the issue of blood pressure, with little regard to any other risk factors or biomarkers resulting from a variation in salt intake.
Sodium and chloride ions play an important role in the firing of the nervous system neurons. Changes in the concentrations of sodium and chloride ions cause an action potential to fire, allowing a neuron to send a signal to other cells. This results in sending the proper signals throughout the body to elicit all of our physiological reactions including mechanical movement of muscles. Changing the consumption of salt has a minimal impact on the nervous system. Only at extreme levels of sodium deficiency will responses in the nervous system be noticed.
METABOLISM AND DIGESTION
Almost all the salt taken in with food or beverages is quickly absorbed from the small intestine and rapidly finds its way to the circulatory system and the extracellular space of tissues. During rapid growth, a considerable amount of sodium is taken up by the skeletal system and other tissues. After maturity, in a healthy person, all salt that is taken in, regardless of quantity, is compensated for by the daily elimination of the same quantity through our normal excretory channels. In fact, our kidneys are capable of filtering an incredibly large quantity of sodium on a daily basis (the daily equivalent of six pounds of salt).
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.
Salt is our main dietary source of chloride, 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.
So we need salt for digesting carbohydrates and proteins; we also need salt for digesting fats as sodium is involved in the manufacture of bile, which emulsifies fats so that they can be absorbed.
SALT AND THE BRAIN
Salt is critical for development of the glial cells in the brain. Between 1984-1991, Mary Enig, PhD, served as an expert witness in several law suits involving two brands of chloride-deficient soy formula, Neo-Mul-Soy and CHOFree, both produced by a company called Syntex. The plaintiffs argued that by removing chloride (in the form of sodium chloride) from the formula, their children did not achieve their full intellectual potential. Dr. Enig testified that chloride was essential for the growth of the brain and development of neurological function, and that sodium activated an enzyme needed for the formation of glial cells.3 Syntex went out of the infant formula business because of adverse publicity about their products, and the formula industry now knows better than to produce formula without salt, but 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.
The adrenal glands are responsible for the release and regulation of over fifty 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 a number of adrenal hormones.
Craving salt is a sign of poor adrenal function. The adrenal hormone aldosterone helps regulate blood pressure. 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.
LOW SALT HAZARDS
In 1936, a British researcher named McCance published the results of a seminal study in which three human beings were put on a salt-free diet combined with sweating, to quickly reduce the salt levels in the body.4 They immediately lost weight and began to look ill. Their sense of taste and smell was affected—foods became tasteless and fatty foods made them nauseous. Even though they drank a lot of water, they got no relief from the sensation of thirst. Two of the three were troubled by nightmares. They suffered from frequent cramps, they became apathetic, had difficulty speaking and their mental capacity was dulled. All returned to normal health and vigor shortly after resuming salt intake.
In a study with rats, researchers found that rats on salt-deprived diets shied away from activities they normally enjoyed—a sign of depression. They concluded that salt is a natural mood booster.5
By the way, one hazard of beer drinking is a disease called Beer Potomania, a condition of low blood sodium common among beer drinkers. The condition is characterized by fatigue, confusion, dizziness and in extreme cases coma—so if you pass out at the bar, too much beer is not necessarily to blame, it might be a case of not enough salty peanuts.6
A BRIEF HISTORY OF SALT
Demonization of a substance so vital to our health could only happen in a society ignorant of the history of salt.
The use of salt by humans is intimately connected with our advance from a nomadic stone age life of hunting and gathering, to agriculture in which grain cereals became an important food. Salt is needed to make these foods taste good, and also to preserve meats and dairy foods for storage and transport. Increased use of salt led to increased production of glial cells in the brain, the cells that make us capable of creative thinking and long-term planning. Indeed, in ancient cultures, salt was considered the gift of the gods. Homer referred to salt as a “divine substance” and Plato described it as “especially dear to the gods.” The Celtic word for salt meant “holy” or “sacred.”
The hunter gatherer obtains the salt he needs from the blood of animals (and sometimes the urine), which concentrate salt from the plants that they eat. Areas where there is very little sodium in the soil will support only small numbers of human beings.7
The quest for salt led to the development of the major trade routes in the ancient world. If you look at a map of the world showing the major accessible salt deposits, there you will also see where civilizations developed—in Jordan, the Tigris-Euphrates, the Yellow River of China, the salt swamps in Persia, the deserts of Egypt and the Sahara; in the New World in Central America, the Andes and the Great Lakes; and finally on the seacoasts in areas of abundant sunshine, where salt could be obtained from evaporated sea water.
Roman soldiers were paid partly in salt— our word salary is derived from the Latin word for salt, salarium. The Romans were noted for sausages, called salsus, because so much salt was used to make them tasty and to preserve them. Having control of the salt supplies in the Dead Sea region was critical to the process of Roman empire-building. They needed salt for their vast armies, and to preserve meat and fish for these armies.
An interesting article published in Scientific American, 1963, describes the social influence of salt.8 The salt trade, over land and sea, had military, social and political consequences. The caravans and ships carrying salt needed protection against bandits; thus a system of protection came into existence.
A certain political pattern emerges: 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, where salt was plentiful, farmers and fishermen nourished free societies. In 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 was hopelessly dependent.
In Europe, a large portion of the salt was obtained from low-lying flat lands at the ocean’s edge, where seawater flowed into natural or diked pans and then was evaporated by the action of the sun. From tracing old shorelines, we can see the level of the sea during various areas. At the height of the ancient Greek and Phoenician civilizations, the sea level was more than three feet lower than it is today. For about a thousand years, salt-making in solar pans and peat marshes flourished in the Mediterranean, the Atlantic and the North Sea. But the sea water was rising. By AD 500, the sea water was more than six feet higher (three feet higher than it is today). This may seem an insignificant change but it was enough to wipe out the salt pans. The covering of the salt pans corresponded with the Dark Age of Europe—it wiped out an important source of wealth and commerce and resulted in reduced health and intelligence of the population; only as the sea level became lower again and salt more available did Europe recover, about 1000 AD.
Today we have many sources of salt and we are not dependent on trade routes, or the height of the sea. Modern technology has made salt cheaply available to almost everyone, and this fact alone has had the effect of lifting many population groups out of misery. Yet, if we read the handwriting on the wall, we can see the move to limit and control salt—either to convince us to do this voluntarily, or even to impose salt restriction on the whole population. There is something very sinister about what is going on with salt. Will salt restriction lead us unwittingly into a new dark age?
THE SALT RESTRICTION AGENDA
Attempts to get Americans to restrict salt go back several decades. The salt wars began in 1972 when the National High Blood Pressure Education Program, a coalition of thirty-six medical organizations and six federal agencies essentially declared that salt was an unnecessary evil. In 1978, one researcher called salt, “the most dangerous food additive of all.”9
Mary Enig, PhD, recalls attending a lecture for the Society for Nutrition Education back in the early 1980s. The speaker was Kristin McNutt, who had been retained by the MSG Foundation. (When manufacturers lower the salt content of food, they usually choose to increase the artificial flavorings, like MSG.)
McNutt said, “It’s just like what we did before the McGovern Committee hearings. In order to get media attention, we said that salt causes high blood pressure. We knew it wasn’t true but we had to get their attention.” It was clear to Enig that agents like McNutt had infiltrated key nutrition groups to promote a no-salt agenda.10
In 1978, the activist group Center for Science in the Public Interest began lobbying Congress to require the labeling of high-salt foods; the FDA got on board in 1981, aiming to reduce the nation’s salt intake. Now the mandate to reduce salt intake is part of the dietary guidelines.
The recent 2010 USDA Dietary Guidelines recommend reducing salt consumption to 3.5 grams, less than the teaspoon that constitutes our absolute requirement for salt, down from 6 grams in the 2005 Guidelines.
The interesting thing about the 2010 Dietary Guidelines Committee’s call for more salt restriction, is that this time the food companies are not objecting. In fact, a number of food companies have announced that they will be reducing the salt content of their products by 20 percent. This includes many food giants, such as Kraft Foods and Nestlé. We now have a similar announcement from Frito-Lay regarding their salted potato chips.
Of real concern is the fact that these announcements about salt reduction just happen to have occurred as a new salt substitute, Senomyx, is readied to enter the marketplace. The Senomyx salt substitute is clearly a chemical product that works in the body as a neurological agent, causing an individual to perceive a salty taste. It would seem to be nothing more or less than a neurotrophic drug.
Because the maker of the Senomyx product calls it a food, their salt substitute does not require the extensive testing that would be required by the FDA if it were called a pharmaceutical. To our knowledge, there has been no testing of the Senomyx salt substitute for safety, and it is so potent that the amount needed in food is below the amount requiring FDA approval. Furthermore, it will never be disclosed on food labels as Senomyx—Senomyx can be used in or called “artificial flavor.”
We can easily predict the results of using a salt substitute instead of real salt—more health problems of every description, including mental retardation, heart failure, failure to thrive. . . and obesity—because our bodies really do need salt. What happens when we eat foods that taste salty but don’t satisfy our requirements for salt? We will feel the urge to eat more and more until our requirements for salt are satisfied.
RECENT CARDIOVASCULAR EVIDENCE
While the “experts” insist on salt restriction as a way of preventing heart attacks, high blood pressure and strokes, evidence to the contrary continues to accumulate. A 2010 (May 4) government-funded study published in the Journal of the American Medical Association finds that even modest reductions in salt intake are associated with an increased risk of cardiovascular disease and death.11 In addition, the increased risk of death was evident within the range recommended by the U.S. government’s Dietary Guidelines on sodium, which means U.S. citizens who follow the dietary guidelines on sodium will be at risk.
The study concludes that lower sodium is associated with higher mortality. “Taken together, our current findings refute the estimates of computer models of lives saved and health care costs reduced with lower salt intake. They do also not support the current recommendations of a generalized and indiscriminate reduction of salt intake at the population level,” wrote the authors.
Likewise, an examination of the largest U.S. federal database of nutrition and health (NHANES), published in the Journal of General Internal Medicine, found a higher rate of cardiac events and death with patients put on low-salt diets—a result perfectly consistent with the JAMA study.12
If salt consumption and hypertension were linked, both would be rising. But a 2010 paper by two Harvard researchers shows that while hypertension has increased among Americans over the last forty years, sodium consumption has remained flat.13
A 2010 Harvard study linked low-salt diets to an increase in insulin resistance, the condition that is a precursor to type 2 diabetes. Subjects on the low-salt diet developed insulin resistance withint seven days!14 Recent studies out of Australia show that individuals with type 1 or type 2 diabetes die in much greater numbers when placed on a salt restricted diet.15
Because of declining renal function in the aging body, the kidneys retain less sodium. Recent studies have shown that elderly people with hyponatremia (low sodium levels), have more falls and broken hips and a decrease in cognitive abilities.16
A 2007 study found that babies with low birth weight are also born with low sodium in their blood serum because their mothers were on low-salt intakes.17 Another study found that infants with low sodium may be predisposed to poor neurodevelopmental function between the ages of ten and thirteen.18
Regarding the lungs, some have hypothesized that salt may impede lung function and be problematic for asthmatics or others with respiratory ailments. The Center for Science in the Public Interest claims “High-salt diets impair lung function and worsen asthma symptoms,” while World Action on Salt and Health goes so far as to state: “There is evidence that bronchial reactivity in people with asthma is linked with salt intake. A recent review of epidemiological and intervention studies demonstrated that reducing salt intake may help to reduce the severity of an asthma attack and other breathing problems.”19 The long-awaited definitive study of the question was published in June 2008, headlined: “Low-sodium advice for asthmatics should be taken with a pinch of salt.”20 In short, science confirms salt is blameless with regard to asthma, which confirms the wisdom of many doctors who had routinely prescribed extended visits in salt mines for those suffering asthma and other respiratory diseases.
Does salt cause obesity? Anti-salt advocates continually call for reduction of this non-caloric ingredient in our diets. True, salt makes food taste good and people are more likely to eat more food that’s palatable than food they find bland and unappealing, but there is no metabolic association of salt intakes with the likelihood of developing obesity.21 Rather, it is likely that salt restriction—especially coupled with the use of taste bud-tricking salt mimickers—will lead to an increase in obesity as people binge and splurge in an effort to satisfy their requirements for salt.
The campaign against salt is a perfect example of the law of unintended consequences. Researchers, politicians, medical professionals and journalists push their no-salt agenda as a surefire way to limit disease when all the evidence points to the opposite—increased health problems in young and old, diminished brain function, increased confusion, and a boon to the food processing and medical industries. With very few exceptions, there is no reason to fear the salt shaker, just put that salt on real, home-prepared food and enjoy!
Salt, Essential Nutrient
Message from The Salt Institute
Salt is an essential nutrient. This is a technical descriptor, not marketing hype. An essential nutrient is one required for life that the body cannot produce itself and which is required for good health. For humans, salt is as essential as water. We can perish from too little salt as we can of thirst. The human body contains about eight ounces of salt. The amount of salt is regulated in our bodies by our kidneys and by perspiration.
One component of salt, sodium (Na), is involved in muscle contraction including heartbeat, nerve impulses, and the digestion of body-building protein. Sodium is easily absorbed and is active in the absorption of other nutrients in the small intestine. Sodium is the major extracellular electrolyte responsible for regulating water balance, pH, and osmotic pressure. It is important in nerve conduction. Because of sodium’s importance to the body, several interacting mechanisms, including generation of hormones angiotensin and aldosterone, adjust the system in the event of consumption of insufficient amounts of salt, which would threaten the body’s nerves and muscles and interfere with the sodium-potassium “pump” that adjusts intra- and extra-cellular pressures. If your salt intake varies widely, these mechanisms activate to ensure that your body remains healthy, maintaining a relatively constant blood pressure.
The other component of salt, chloride (Cl), is also essential to good health. It preserves acid-base balance in the body, aids potassium absorption, supplies the essence of digestive stomach acid, and enhances the ability of the blood to carry carbon dioxide from respiring tissues to the lungs.
Because salt is essential to good health, the human body is hard-wired with an innate salt appetite. Around the world, population salt intakes vary somewhat, but nearly all fall within what eminent medical researcher Bjørn Folkow termed the “hygienic safety range” of sodium intake, between 2,300 mg per day and 4,600 mg per day or even 5,750 mg per day. In common English measures, that would be one to two or two-and-one-half teaspoons of salt per day. A few remote peoples lacking access to salt apparently consume far below 2,300 mg per day of sodium while a few others consume diets heavy with salted fish and vegetables, but virtually every society with access to salt consumes amounts within the “safety range.” Intakes in North America and most of Europe average about 3,500 mg per day — right in the middle of this range. Some public health agencies feel these intake levels are too high, but consumption levels are unchanged over the past century when medical instruments allowed accurate measurements.
REFINED AND “FORTIFIED” SALT
Most table salt today is “refined” or “purified,” a process that usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most “impurities,” that is magnesium and trace minerals. Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are kiln-dried.
During the drying process, an anti-caking compound is added to the brine—this ensures that the salt will “pour when it rains.” Some anticaking agents used are sodium ferrocyanide, tricalcium phosphate, calcium or magnesium carbonates, fatty acid salts (acid salts), magnesium oxide, silicon dioxide, calcium silicate, sodium aluminosilicate, and calcium aluminosilicate. The ferrocyanide and aluminosilicate compounds give the most cause for concern.
Since salt use is ubiquitous, health officials have naturally eyed it as a vehicle for delivering nutrients considered in short supply. The practice of adding iodine to salt began in the 1920s—salt manufacturers, notably Morton’s Salt, added minute amounts of potassium iodide, sodium iodide, or sodium iodate to help reduce the incidence of iodine deficiency in humans. Tested first on school girls in Cleveland, the iodized salt completely eliminated goiters. In Switzerland, many cantons introduced iodized salt, and those districts where it was used experienced a decline almost to zero in the incidence of goiter. In spite of these successes, mass iodine supplementation programs met with much resistance, especially as side effects emerged. While the programs almost completely eliminated goiter, the prevalence of autoimmune thyroiditis increased in areas with iodated water or in those using iodized salt. Iodization of salt, especially as it is used in processed food, poses real problems for those who are sensitive to iodine.
Some European countries, where water fluoridation is not practiced, also add fluoride to table salt. In France, 35 percent of table salt sold contains either sodium fluoride or potassium fluoride and use of fluoridated salt is widespread in South America. Added folic acid gives salt a yellow color, and health officials in some countries have considered adding iron to salt.
Our advice: avoid all processed, refined, “enhanced,” and “fortified” salt; stick to unrefined sea salt or mined salt, of which there are many brands listed in the Weston A. Price Foundation Shopping Guide.
PREMATURE BABIES NEED SALT!
Salt is critical to the brain development of premature babies. In premature babies, language, memory, intelligence and coordination were all better in children whose diets had been supplemented with salt shortly after birth.
The study focused on 37 children who had been monitored since birth. All had been born before or at 33 weeks of pregnancy. Between the ages of 10 and 13 the children were tested for competency in movement and balance, IQ, memory, learning, and language. They were also assessed for behavioral problems. All the tests used were recognized and validated measures of performance.
Sixteen of the children had received a salt supplement of 4 to 5 millimoles per kg of body weight a day – about one twentieth of a teaspoon – in their feed four to 14 days after birth; the other 21 children had not.
The results showed that on average, the children whose feeds had been supplemented with salt scored 10 per cent higher than their prematurely born peers in memory, learning and language. And their physical coordination, IQ, general memory and behavior were significantly better.
The authors conclude that babies born several weeks early require a higher salt intake for their first two weeks of life than babies born after the full nine months or thereabouts. And they suggest that failure to supplement a premature newborn’s diet with salt could compromise their subsequent neurodevelopment in childhood.
Salt Institute Press Release
New dietary guidelines on sodium will increase obesity and health risks for Americans Washington, DC — February 10, 2011: At the Oral Comment Meeting of the Dietary Guidelines Advisory Committee, held today at USDA headquarters, the Salt Institute cautioned that instead of improving the health of consumers, the 2010 Dietary Guidelines will result in confusion and unintended consequences. Reduced salt in food will fuel the obesity epidemic as individuals will consume more to satisfy their natural sodium appetite and their hunger for taste satisfaction. It will also lead to other serious unintended health risks.
Salt Institute Vice President of Science and Research, Morton Satin said that the Dietary Guidelines have become far more a reflection of activist ideology than sound science. “The purpose of the five-year review process is to objectively examine all the new evidence before making recommendations, yet, before the process began, key Committee members openly stated the expected outcomes regarding salt, thereby compromising the process and making any final recommendations a forgone conclusion,” Satin said.
The recommendation of 1,500 mg sodium amounts to less than four grams of salt per day. Available data confirms that there is no modern society that consumes so little salt, thus making the Dietary Guidelines recommendation a trial on more than 300 million Americans. Population-wide interventions to reduce health risks can only work when there are no negative health consequences—which is clearly not the case with salt reduction. Elevated renin-angiotensinaldosterone activity, the body’s natural hormonal response to reduced salt intake, will drive the population’s health risks to higher levels. Peer-reviewed evidence further suggests the possibility of unintended consequences such as cognitive impairment, adverse infant neurodevelopment and increased attention deficits and falls in the elderly, resulting from insufficient salt intake.
Satin went on to state, “Previous Guidelines made rigid recommendations on fat, portraying them as scientifically sound, yet had to be withdrawn when the actual science proved them wrong. I believe this grim lesson will be repeated once more with salt. Healthy humans, all around the world, consume salt within a relatively narrow range, controlled by their natural physiological control mechanisms. Trying to trump biology with flawed policy is pure folly.”
Studies have confirmed the importance of a balance of electrolytes: sodium, calcium, potassium and magnesium. When the body loses electrolytes in perspiration or when suffering diarrhea, serious consequences ensue. Likewise, when we drink only water after exercise, the usual electrolyte balance is not restored and “water intoxication” or hyponatremia occurs. Marathon runners are warned to make sure they consume extra salt, and diarrhea is treated with Oral Rehydration Therapy to replace lost electrolytes. The consequences of not replacing salt can be serious, even deadly.
It is sodium that makes “soft drinks” soft. While modern soft drinks are a witch’s brew of unhealthy ingredients, they do supply salt and for that reason alone give needed relief after work in the out of doors or exercise that stimulates a sweat. But soft drinks need not be unhealthy. Lacto-fermented beverages contain small amounts of salt, as does kombucha. If you are thirsty for water—plain or sparkling—be sure to add a pinch of salt to it. Otherwise the body simply gets rid of the water as fast as possible so as not to further dilute low salt levels. If you are using unrefined salt, you will be taking in small amounts of magnesium, and even calcium and potassium, as well.
MORE STUDIES VINDICATING SALT
1985. A ten-year study of nearly eight thousand Hawaiian Japanese men concluded: “No relation was found between salt intake and the incidence of stroke.”
1995. An eight-year study of a New York City hypertensive population stratified for sodium intake levels found those on low-salt diets had more than four times as many heart attacks as those on normal-sodium diets—the exact opposite of what the “salt hypothesis” would have predicted.
1997. An analysis by NHLBI’s Dr. Cutler of the first six years’ data from the MRFIT database documented no health outcomes benefits of lower-sodium diets.
1997. A ten-year follow-up study to the huge Scottish Heart Health Study found no improved health outcomes for those on low-salt diets.
1998. An analysis of the health outcomes over twenty years from those in the massive U.S. National Health and Nutrition Examination Survey (NHANES I) documented a 20 percent greater incidence of heart attacks among those on low-salt diets compared to normal-salt diets.
1998. A health outcomes study in Finland, reported to the American Heart Association that no health benefits could be identified and concluded “…our results do not support the recommendations for entire populations to reduce dietary sodium intake to prevent coronary heart disease.”
1999. A further analysis of the MRFIT database, this time using fourteen years’ data, confirmed no improved health benefit from low-sodium diets. Its author conceded that there is “no relationship observed between dietary sodium and mortality.”
2002. In September 2002, the prestigious Cochrane Collaboration produced the latest and highest-quality meta-analysis of clinical trials. It was published in the British Medical Journal and confirmed earlier meta-analyses’ conclusions that significant salt reduction would lead to very small blood pressure changes in sensitive populations and no health benefits.
2003. In June 2003, Dutch researchers using a massive database in Rotterdam concluded that, “variations in dietary sodium and potassium within the range commonly observed in Westernized societies have no material effect on the occurrence of cardiovascular events and mortality at old age.”
2004. In July 2004, the first “outcomes” study identifying a population risk appeared in Stroke magazine. Researchers found that in a Japanese population, “low” sodium intakes (about 20 percent above Americans’ average intake) had one-third the incidence of fatal strokes of those consuming twice as much sodium as Americans.
2006. A March 2006 analysis of the federal NHANES II database in The American Journal of Medicine found a 37 percent higher cardiovascular mortality rate for low-sodium dieters.
2007. A February 2007 article reported in the International Journal of Epidemiology described a study of over forty thousand Japanese over seven years and found “the Japanese dietary pattern was associated with a decreased risk of CVD mortality, despite its relation to sodium intake and hypertension.”
2007. An October 2007 analysis of a large Dutch database published in the European Journal of Epidemiology documented no benefit of low-salt diets in reducing stroke or heart attack incidence nor lowering death rates.
2008. A May 2008 examination of NHANES II (the largest U.S. federal database of nutrition and health) published in the Journal of General Internal Medicine confirmed two earlier studies of earlier NHANES surveys that there is no health benefit (CVD or all-cause mortality) for those on low-sodium diets.
THERAPEUTIC USES OF SALT
Salt therapy, sometimes called halotherapy or speleotherapy, is the therapeutic use of salt mines, caves or other forms of exposure to salt air, including visits to the ocean, particularly for respiratory diseases.
Records of improvements in the breathing of miners exposed to salt air date from Roman and medieval times. Dr. Feliks Boczkowski, a physician at the Polish salt mine at Wieliczka, wrote in 1843 that the miners there did not suffer from lung diseases. His successor set up a spa based upon these observations. Halotherapy is now practised in places such as Bystrianska in Slovakia, Wieliczka in Poland and Solotvyno in Ukraine.
Halogenerators are used to simulate the salted atmosphere of salt mines. These highly developed machines crush rock salt into dry micron sized particles, ionize the particles, and release them into the air. Salt particles of sizes 0.1-2.5 microns are able to escape the natural defenses of the upper airways and travel deep into the lung to the level of the alveoli.
Salt lamps are another method of ionizing rocksalt. A large crystal of natural salt is hollowed out and heated with a tealight or lightbulb.
The easiest way to use salt therapy is to breathe an aerosol of concentrated salt water (3-7 percent sodium chloride). This treatment has been found effective as a treatment for the heavy build up of mucus typical of cystic fibrosis. The benefits of this were first noticed by sufferers who regularly surfed in Australia and so were exposed to the natural aerosol of the salt spray.
The use of saline solution delivered by a nebulizer to treat bronchiolitis in children has also been systematically reviewed. The conclusion was that, “Current evidence suggests nebulized 3 percent saline may significantly reduce the length of hospital stay and improve the clinical severity score in infants with acute viral bronchiolitis.”
Those suffering from asthma or sinus conditions have reported significant relief from salt therapy using a nebulizer.
Variations in Salt Metabolism
Although health authorities such as the National Heart, Lung and Blood Institute (NHLBI ) recommend blanket restrictions on sodium intake for the whole population in order to reduce the burden of blood pressure-related cardiovascular diseases, the tenth edition of the well respected textbook Modern Nutrition in Health and Disease (2006) acknowledges that “the role of increased sodium intake as a cause of hypertension is still hotly debated, and raging controversy continues.”1 The inconsistent effects of sodium restriction in clinical trials helps fuel the controversy. When researchers pooled together the results of fifty-six trials, sodium restriction lowered blood pressure to the greatest degree among institutionalized elderly people with high blood pressure.2 There was little or no effect in young people with high blood pressure, and no effect at all in young people with normal blood pressure. Although much of this variation may be a result of differences in the length and quality of studies, much of it may be a result of a phenomenon called “salt-sensitive hypertension.” According to this view, some people do experience an increase in blood pressure when they consume more salt, while others do not. There is likely to be genetic variation that contributes to salt-sensitivity, but the evidence to date suggests that the overall dietary context is the most important determinant of a person’s response to salt.
Researchers currently estimate that about fifty to sixty million American adults have high blood pressure, fifty-eight million are salt-sensitive, and twenty-six million are both salt-sensitive and hypertensive.3 Thus, somewhat less than half of those with high blood pressure would be able to reduce it by consuming less salt. The estimated thirty-two million Americans who are salt-sensitive but have normal blood pressure may be predisposed to develop high blood pressure later in life. African Americans are much more likely to be salt-sensitive than Caucasians. Extensive investigations of the associations of variations in more than two dozen specific genes with the incidence of salt-sensitive hypertension, however, have produced very inconsistent results.3 This is probably because variations in many genes must interact with one another and with dietary factors in order to render a person salt-sensitive.
The dominant effect of dietary context can be seen in clinical trials that use dietary factors other than sodium to change people’s response to salt. Studies suggest that sodium bicarbonate increases blood pressure only half as effectively as sodium chloride in salt-sensitive individuals.4 Sodium citrate produces little or no increase in blood pressure in salt-sensitive individuals.5 The addition of potassium bicarbonate to the diet dose-dependently reduces the incidence of salt-sensitivity and may even abolish it.6 These findings are consistent with research suggesting that mild metabolic acidosis may be at the root of salt-sensitivity.5,7 If this is the case, we might expect calcium, magnesium and alkaline-rich foods such as milk, potatoes, fruits, vegetables, and beans to be protective. Nevertheless, the best way to protect against mild acidosis is probably not to obsess over the relative balance of acids and bases in whole foods, but instead to focus on maximizing metabolic efficiency by eating a nutrient-dense diet that is not overly restrictive in any particular macronutrient, including carbohydrate, by normalizing body weight if necessary, and by normalizing any autoimmune conditions or thyroid disorders that might be present.
(Sidebar by Chris Masterjohn)
1. Oh MS, Uribarri J. Electrolytes, “Water, and Acid-Base Balance.” In: Shils ME, Shike M, Ross AC, Cabellero B, Cousins RJ, eds. Modern Nutrition in Health and Disease: Tenth Edition. Baltimore, MD: Lippincott Williams & Wilkins (2006) pp. 149-93.
2. Midgley JP, Matthew AG, Greenwood CM, Logan AG. Effect of reduced dietary sodium on blood pressure: a meta-analysis of randomized controlled trials. JAMA. 1996;275(20):1590-7.
3. Sanada H, Jones JE, Jose PA. Genetics of salt-sensitive hypertension. Curr Hypertens Rep. 2011;13(1):55-66.
4. Schmidlin O, Forman A, Sebastian A, Morris RC Jr. Sodium-selective salt sensitivity: its occurrence in blacks. Hypertension. 2007;50(6):1085-92.
5. Sharma AM, Kribben A, Schattenfroh S, Cetto C, Distler A. Salt sensitivity in humans is associated with abnormal acid-base regulation. Hypertension. 1990;16:407-13.
6, Morris RC Jr, Sebastian A, Forman A, Tanaka M, Schmidlin O. Normotensive salt sensitivity: effects of race and dietary potassium. Hypertension. 1999;33(1):18-23.
7. Sharma AM, Cetto C, Schorr U, Spies KP, Distler A. Renal acid-base excretion in normotensive salt-sensitive humans. Hypertension. 1993;22:884- 890.
1. Study Counts Benefits of Cutting Salt. http://online.wsj.com/article/SB10001424052748704320104575015453863612776.html. Strangely, we are unable to find the study referred to in MedLine or on the New England Journal of Medicine website.
3. Mary G. Enig, PhD, personal communication.
4. McCance. Nutrition Reviews Vol 48, March 1990, pp 145-147.
5. Morris and others. Salt craving: the psychobiology of pathogenic sodium intake. Physiol Behav. 2008 Aug 6;94(5):709-21. Epub 2008 Apr 13.
6. American Journal of Kidney Diseases, Vol 31, No 6, June 1998, pp 1028-1031.
7. MR Bloch, The Social Influence of Salt, July 1963, reprinted in Scientific American, 1978.
10. Mary G. Enig, PhD, personal communication.
11. Stolarz-Skrzypek and others. Fatal and Nonfatal Outcomes, Incidence of Hypertension, and Blood Pressure Changes in Relation to Urinary Sodium Excretion. JAMA.
2011;305(17):1777-1785. doi: 10.1001/jama.2011.574.
12. Cohen and others. Sodium intake and mortality follow-up in the Third National Health and Nutrition Examination Survey (NHANES III). J Gen Intern Med. 2008 Sep;23(9):1297-302. Epub 2008 May 9.
13. Bernstein and Willett. Trends in 24-h urinary sodium excretion in the United States, 1957-2003: a systematic review. Am J Clin Nutr. 2010 Nov;92(5):1172-80. Epub 2010 Sep 8.
15. Ekinci and others, Dietary Salt Intake and Mortality in Patients With Type 2 Diabetes, Diabetes Care April 1, 2011 34:861-866.
16. Renneboog and others. Mild Chronic Hyponatremia Is Associated With Falls, Unsteadiness, and Attention Deficits. American Journal of Medicine, Volume 119, Issue 1, Pages 71.e1-71.e8, January 2006.
17. Shirazki and others. Lowest neonatal serum sodium predicts sodium intake in low birth weight children. Am J Physiol Regul Integr Comp Physiol. 2007 Apr;292(4):R1683-9. Epub 2006 Dec 14.
18. Al-Dahhan and others. Effect of salt supplementation of newborn premature infants on neurodevelopmental outcome at 10–13 years of age. Arch Dis Child Fetal Neonatal Ed. 2002 March; 86(2): F120–F123. doi: 10.1136/fn.86.2.F120.
21. Is Salt Implicated in Our Obesity Epidemic? http://www.saltinstitute.org/content/download/257/1479.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation, Summer 2011