SUMMARY: This post is all about the salt controversy and discusses Salt: How much, Autoimmunity, & Iodine Deficiency. In sum, studies now show salt limits that are within a moderate salt consumption range (between 2,645 to 4,945 mg per day), reduces the risk of death or a serious event such as a heart attack or stroke and below or above these limits has increased risk of such. Studies now show autoimmunity associations with ordinary table salt through Th17 releasing up to 10x more cytokines when exposed to refined salt. Last, some groups have borderline iodine deficiency whereas other groups are high (children). Also included is how much salt do we really eat and a heads up: Those eating a Whole Foods diet may not be getting enough salt to be in that optimal bell curve range (between 2.645 to 4,945 mg per day).
What is the safest sodium limits?
The study, Compared With Usual Sodium Intake, Low- and Excessive-Sodium Diets Are Associated With Increased Mortality: A Meta-Analysis, read full text here, found that, “as with all other essential nutrients, there was a U-shaped correlation between sodium intake and health outcomes. When consumption deviated from the 2,645 — 4,945 mg range mortality increased, so that both excessively high and low consumption of sodium were associated with reduced survival. The study also found that there is little-to-no variation in health outcomes between individuals as long as their consumption remained within the ideal intake range (2,645 — 4,945 mg/day).” See also Levels of sodium intake recommended by CDC associated with harmful health outcomes, study finds.
- Deaths increased when daily consumption was less than 2,645 mg or above 4,945 mg.
- Between 2,645 and 4,945 mg of salt a day had little or no variation in death.
For perspective, Mayo Clinic notes that a single teaspoon of table salt, which is a combination of sodium and chloride, has 2,325 milligrams (mg) of sodium. These limits contradict current public health policy in the United States but is unlikely to change it. Realize, both excessively high and low consumption of salt were associated with reduced survival.
“Current guidelines from U.S. government agencies, the World Health Organization, the American Heart Association and other groups set daily dietary sodium targets between 1,500 and 2,300 milligrams or lower, well below the average U.S. daily consumption of about 3,400 milligrams.” –Wall Street Journal, Low-Salt Diets May Pose Health Risks, Study Finds Findings Are Latest Challenge to Benefits of Aggressively Low Sodium Targets (if the link doesn’t work just Google the title):
How much salt does the world really consume?
WHO cites a 5 gram/day upper sodium limit:
According to World Health Organization, Salt Fact Sheet, most of the world’s populations consume on average 9–12 grams per day, or around twice the recommended maximum level of intake which WHO places at 5 grams per day. WHO further explains, “Salt intake of less than 5 grams per day for adults helps to reduce blood pressure and risk of cardiovascular disease, stroke and coronary heart attack. The principal benefit of lowering salt intake is a corresponding reduction in high blood pressure.” This is interestingly similar to the 4,945 mg/day upper limit for sodium consumption findings from the recent studies.
The World’s salt consumption graphically depicted:
The below charts from Some Implications of Changing Patterns of Mineral Consumption, dated 2000, shows salt consumption in 18 of most populous countries, in tons per capita, for comparatives. USA, Germany, UK, France, and Japan lead the pack. For perspective, the UK average salt intake is 8.1 gm/day according to the consumption of both added salt and table salt has been reduced: Average salt intake in the UK measured in random samples of adults has fallen from 9.5g to 8.1g per day):
Figure 17 is a plot of per capita consumption of salt for eighteen countries, with reported statistical data on production and trade for the years 1970, 1975, 1980, 1985, 1990, and 1995. Salt differs from the three mineral commodities discussed earlier in an important respect — world per capita consumption of salt (production divided by world population) dropped between 1970 and 1995. In the 18 countries shown in figure 17, per capita consumption of salt has generally been between a few kilograms per person and 200 kilograms per person. Figure 18 shows the per capita consumption of salt in the five developed countries. Per capita consumption of salt has fallen slightly in France, the UK, and the United States. Per capita consumption has risen slightly in Japan. The plot of per capita consumption of salt for Germany shows more variability than other countries due to reunification. Per capita consumption of salt rose in the Federal Republic of Germany through 1990 but per capita consumption fell in the reunified Germany in 1995. Of developing countries, Brazil has experienced significant growth in salt consumption. –Some Implications of Changing Patterns of Mineral Consumption
Ummm… so, what factors other than sodium may be contributing to the heart disease…?
Cardiac risk factors and prevention, The wrong white crystals: not salt but sugar as aetiological in hypertension and cardiometabolic disease explains it is the sugar and not the salt:
“the benefits of [recommendations to reduce consumption of processed food] might have less to do with sodium—minimally related to blood pressure and perhaps even inversely related to cardiovascular risk—and more to do with highly-refined carbohydrates. It is time for guideline committees to shift focus away from salt and focus greater attention to the likely more-consequential food additive: sugar. A reduction in the intake of added sugars, particularly fructose, and specifically in the quantities and context of industrially-manufactured consumables, would help not only curb hypertension rates, but might also help address broader problems related to cardiometabolic disease.”
Check out what 30 grams of carbohydrates (sugar) really looks like, two ways from the Diet Doctor, Andreas Eenfeldt, a Swedish medical doctor specialized in family medicine, and how much the US has increased grain (sugar) consumption:
New England Journal of Medicine looks at the three studies that find moderate sodium intake optimal:
Three recent studies are at issue as their findings are turning the current low target sodium recommendations on its head. This video: New England Journal of Medicine (NEJM) video, Global Sodium Consumption, evaluated them:
First study: Association of Urinary Sodium and Potassium Excretion with Blood Pressure, by Mente et al.
Subjects: 102,216 adults from 18 countries. Method: single fasting urine levels of sodium and potassium were used to estimate 24-hour excretion, providing an indirect estimate of dietary intake. Findings: the association of sodium with BP was greatest in hypertensives, the elderly, and those who had the highest intakes of salt. It was greatest in those ingesting over 6 grams of sodium a day, modest in those ingesting 3-5 grams, and not significant in those ingesting less than 3 grams a day. They found an inverse relationship for potassium: higher levels of potassium were associated with lower blood pressures.
Second study: Urinary Sodium and Potassium Excretion, Mortality, and Cardiovascular Events, by O-Donnell et al.
Subjects: 101,945 adults from 17 countries. Method: as in the first study, single fasting urine tests were used to estimate 24-hour urinary sodium and potassium excretion; those estimates were compared to a composite outcome of death and major cardiovascular events. Findings: mean sodium excretion was 4.93 g. Compared to a reference range of 4.00-5.99 g a day, the odds ratio for death and cardiovascular events was 1.15 for high sodium excretion (over 7 g a day) but was even greater at 1.27 for a low sodium excretion (below 3 g). Higher potassium excretion was associated with decreased risk.
Third study: Global Sodium Consumption and Death from Cardiovascular Causes, by Mozaffarian et al.
The authors reviewed 205 studies on sodium consumption from 66 countries. Estimated mean global consumption was 3.95 grams a day, with regional means varying from 2.18 to 5.51. Daily sodium intake >6 grams a day was associated with increased risk of mortality and cardiovascular events. Surprisingly, so was intake of <3 grams. The lowest risk was in the 3-6 gram range. They used a computer model to estimate that 1.65 million deaths a year could be attributed to a sodium intake of greater than 2 grams a day. That’s about 10% of all cardiovascular deaths. The rate ranged from 4 deaths per million adults per year in Kenya to 1,967 per million in Georgia.
The conclusion found that too low and too high is high risk, but least risk is moderate sodium consumption.
The too low sodium health concern is especially relevant to those eating a whole foods diet (low in processed, prepared, and restaurant foods) who may not be consuming enough sodium (above the 2,645 mg lower limit found in the studies)
and that increases your risk of death or a serious event such as a heart attack or stroke: Relevant New England Journal of Medicine (NEJM) video, Global Sodium Consumption slides are:
Interestingly, the Scientific American article, It’s Time to End the War on Salt, The zealous drive by politicians to limit our salt intake has little basis in science summarizes the research and shows that sodium does not dramatically alter blood pressure. Matter of fact, this article does an incredible job summarizing at least eleven research studies looking at the association between salt to heart disease (which has always been tenuous.) The article’s conclusion calls into question the common wisdom that excess salt is bad for you; for every study that suggests that salt is unhealthy, another does not. Those findings ranged from sodium has no effect on heart disease to the more sodium people ate, the less likely they were to die from heart disease.
The Wall Street Journal, Low-Salt Diets May Pose Health Risks, Study Finds Findings Are Latest Challenge to Benefits of Aggressively Low Sodium Targets, reported (if the link doesn’t work just Google the title):
- The new study, which tracked more than 100,000 people from 17 countries over an average of more than three years, found that those who consumed fewer than 3,000 milligrams of sodium a day had a 27% higher risk of death or a serious event such as a heart attack or stroke in that period than those whose intake was estimated at 3,000 to 6,000 milligrams. Risk of death or other major events increased with intake above 6,000 milligrams.
- Participants in the study, known as the Prospective Urban Rural Epidemiology study, or Pure, consumed an average of 4,930 milligrams of sodium a day, based on estimates derived from a single urine sample obtained when they enrolled in the study and were followed an average of 3.7 years. They found that 4.3% of those who consumed less than 3,000 milligrams of sodium either died or suffered a heart attack or stroke or developed heart failure in that time, versus 3.1% with intake between 3,000 and 6,000 milligrams. The percentage rose to 3.2% at levels above 6,000 milligrams and to 3.3% above 7,000 milligrams.
- The findings, published in the New England Journal of Medicine, are the latest to challenge the benefit of aggressively low sodium targets—especially for generally healthy people. Last year, a report from the Institute of Medicine, which advises Congress on health issues, didn’t find evidence that cutting sodium intake below 2,300 milligrams reduced risk of cardiovascular disease.
- The FDA said it intends to review the studies but “continues to recognize the need to reduce the sodium content of the food supply” to help reduce sodium intake.
- Current guidelines are largely derived from short-term studies that found that low-salt diets helped people already diagnosed with hypertension or with borderline high blood pressure to get their readings significantly lower. But studies that show the resulting blood-pressure reduction in such patients reduces risk of death or serious cardiovascular problems are lacking. “There is not a single study, not one, showing [such a] benefit for having a sodium intake of less than 2,300 milligrams,” said Brian Strom, chancellor of Rutgers Biomedical and Health Sciences in New Jersey who wasn’t involved in the study but chaired the Institute of Medicine panel that reported on sodium last year.
- Underscoring the divide among heart experts over sodium intake levels, a separate study Wednesday in NEJM, from researchers at the Harvard School of Public Health, estimated that globally, there were 1.65 million deaths from cardiovascular causes in 2010 attributed to sodium consumption above 2,000 milligrams a day… but said because of the “lack of high-quality data” and “numerous assumptions” that went into the analysis, “caution should be taken in interpreting the findings.”
- Reducing dietary sodium has been a public-health goal for several decades, but meeting the recommended targets is a daunting challenge for most people. Fewer than 1% of Americans are now in compliance, Dr. Strom said. More than three-quarters of dietary sodium comes not from the salt shaker but from processed food and restaurant fare, according to the FDA. Grocery-store aisles and restaurants, according to information on a Texas A&M University website, are rich in sodium: 264 milligrams in two slices of whole-wheat bread; 1,107 in a cup of chicken noodle soup; 639 in a hot dog; 1,093 in a frozen pot pie; 709 in a fast-food cheeseburger. Such levels help explain calls for efforts to work with food makers to reduce sodium content. “Very high levels of sodium intake appear to be associated with bad outcomes,” said Michael Lauer, director of cardiovascular sciences at the National Heart, Lung and Blood Institute. “That’s an important message to keep in mind.”
This Reuters article, Controversial studies say lowest sodium intake may pose risks, reports:
“What these studies show collectively is that there is an optimal level, and lower is not necessarily better,” Dr. Andrew Mente of McMaster University in Hamilton, Ontario, chief author of the blood pressure study, told Reuters Health by phone.”
One thing all the studies confirm: too much salt is bad for you. High amounts contribute to high blood pressure, stroke, heart attack, kidney problems and heart failure. Worldwide, daily consumption is usually 3 to 6 grams of sodium, which translates to 7.5 to 15.0 grams of salt. That’s well above the limit of 1.5 to 2.4 grams of sodium each day recommend by the World Health Organization, the American Heart Association and other organizations. “If people are eating a very high level of sodium and they reduce their intake, you get a large reduction in blood pressure,” he said. “But if you’re eating a moderate level of sodium – about what most North Americans eat – and you reduce it to a lower level, you’re not really getting much in return as far as blood pressure reduction is concerned.”
The most dramatic evidence was the study that looked at the link between sodium intake and death, heart attacks and strokes using urine samples to estimate sodium consumption. Led by Mente’s colleague at McMaster, Dr. Martin O’Donnell, it found that consuming less than 3 grams of sodium per day increased the risk of death or major cardiovascular events by 27 percent compared to people who consumed 4 to 6 grams daily. The optimum sodium level was 3 to 6 grams per day. “Both higher and lower levels of estimated sodium excretion were associated with increased risk,” the O’Donnell team concluded. That study shows “there are unintended consequences of going lower” Mente said in a telephone interview.
The study, The population risks of dietary salt excess are exaggerated, reports the optimal range of sodium at 3 to 6 g/day with paradoxical higher rate of events at less than 3 g/day:
The evidence supports a strong association of sodium with BP and cardiovascular disease events in hypertensive individuals, the elderly, and those who consume > 6 g/d of sodium. However, there is no association of sodium with clinical events at 3 to 6 g/day and a paradoxical higher rate of events at < 3 g/day. Therefore, until new evidence emerges, the optimal range of sodium consumption should be considered to be between 3 and 6 g/d. Population-wide sodium reduction is not justified in countries such as Canada.
And there two more salt concerns beyond quantity ingested: autoimmunity and iodine
Did you know: Ordinary Table Salt is associated with autoimmunity:
Mineral rich sea salt contains minerals like magnesium, potassium, calcium and many others (according to Chemical composition of natural sea salt from the Sečovlje salina (Gulf of Trieste, northern Adriatic), the American Heart Association and Mayo Clinic). In cooking whole foods, we do NOT use refined heavily processed ordinary table type salt which is void of any minerals and which also contains added anti-clumping ingredients (see American Heart Association and Mayo Clinic.) It is the latter ordinary mineral-less refined table salt that is used in restaurants as well as most prepared and processed foods, and it is the refined table salt that recently has come under fire for possible links to autoimmune disease (see Study links processed table salt to autoimmune disease, Shaking Out Clues to Autoimmune Disease (National Institutes of Health), and [Refined] Salt Linked to Autoimmune Diseases). NOTE: An association does not mean causation.
This excerpt is from the study, “Study links processed table salt to autoimmune disease,” which showed an association of refined table salt with autoimmune-promoting inflammation:
In order to fend off harmful pathogens, the body relies upon T cells, which help activate the immune cells responsible for targeting bacteria or viruses. Included in the T cells category is a subset of cells known as Th17, which adaptively develop, as needed, to address incoming threats.
When exposed to refined table salt, however, these Th17 cells tend to malfunction, becoming more aggressive than usual. It is in this aggressive state, Th17 cells promote inflammation rather than mitigate it, a phenomenon that a growing number of scientists believes is a trigger for autoimmune disorders.
In the lab, tests revealed that exposure to refined salt causes Th17 cells to release up to 10 times more cytokines than normal. This so-called cytokine “storm” can damage the immune system by overextending it, which in some cases results in the body attacking itself rather than appropriate foreign invaders.
Hafler and colleagues conclude that ” … increased dietary [refined] salt intake might represent an environmental risk factor for the development of autoimmune diseases through the induction of pathogenic TH17 cells”. –[Refined] Salt May Play Role In Autoimmune Disease, Third Study: Confirming Findings in Mouse and Human Cells
Did you know: Some age populations bordered on iodine deficiency. Pass the iodized salt, please? But children bordered on excess iodine.
Borderline iodine deficiency was found for women of childbearing age (excess was found for children) in the Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population, Executive Summary 2012.
“Salt,” and what the CDC says:
The CDC stands by its recommendation for less than 2,300 mg of salt per day for healthy people under 50, and less than 1,500 mg per day for most people over 50 according to an agency representative.
- Most Americans Should Consume Less Sodium. “Ninety percent of Americans exceed the general daily recommended sodium intake limit of 2,300 mg, increasing their risk for high blood pressure, heart disease, and stroke,” according to Janelle Gunn, a public health analyst in the CDC’s division for heart disease and stroke prevention. Most Americans Should Consume Less Sodium and we consume 75% of our sodium in the form of salt from processed and restaurant foods. Salt used for cooking and at the table is only a small amount of the daily sodium intake. Excess sodium can increase your blood pressure and your risk for a heart disease and stroke. Together, heart disease and stroke kill more Americans each year than any other cause.1
According to Samantha Heller, a senior clinical nutritionist at NYU Langone Medical Center in New York City, “what is too much salt or too little is a matter of debate. However, the salt argument is really all about balance. The reality is few people have any idea how much salt they consume in a day. This study highlights the fact that too much or too little salt can affect the physiological functions of the body and increase the risk of death.”
Children need to reduce sodium: Nearly 9 in 10 US children eat more sodium than recommended, and about 1 in 6 children has raised blood pressure, which is a major risk factor for heart disease and stroke later in life.
- Choose the DASH (Dietary Approaches to Stop Hypertension) diet, a Heart-Healthy Diet which is a simple, heart-healthy diet that can help prevent or lower high blood pressure. The DASH diet is low in sodium, cholesterol, and saturated and total fats, and it is high in fruits and vegetables, fiber, potassium, and low-fat dairy products. If you follow the DASH eating plan and also make other lifestyle changes, such as getting more physical activity, you will see the biggest benefits. Learn more about the DASH eating plan on the National Heart, Lung, and Blood Institute’s Web site.
But, what exactly is your dietary sodium load anyway? Read labels, and if eating mainly whole foods (little processed, prepared, and restaurant foods), it’s likely very low which may be problematic.
For most eating a whole foods diet, sodium loads are dramatically reduced from those eating the standard American diet where sodium lurks everywhere. In fact, the CDC, Sodium and Food Sources, notes that “Most of the sodium Americans eat comes from packaged, processed, store-bought, and restaurant foods. Only a small amount comes from salt added during cooking or at the table. In fact, most Americans already get more daily sodium than recommended before they ever pick up a salt shaker.” And, What is processed food? The Dietary Guidelines for Americans define the term “processed food” includes “any raw agricultural commodity [product] that has been subject to processing, such as canning, cooking, freezing, dehydration, or milling.” Processing certain foods can make them last longer by killing organisms in the food or slowing their growth. -The U.S. Federal Food, Drug and Cosmetic Act, Section 201, Chapter II, (gg). So salt is ubiquitous so as to extend shelf life; it’s anywhere and everywhere except for what you buy that doesn’t list ingredients on it (a.k.a. raw produce and often not chicken having broth as a processing additive- read raw chicken labels):
Check out some surprising sodium gluts
Poultry is most often injected with broth (and it’s not your high quality homemade) – read labels and realize broth injected chicken is likely what you get at restaurants and in all prepared food, clients are shocked to taste bread made without salt, high salt in sandwiches, pizza, soup, and cheese is a surprise since there isn’t a particularly strong salt taste, and snack foods which many believe to be top sources of sodium (since the salt on the outside is tasted more intensely then that mixed into batters such as bread or spaghetti sauces) are in fact at the bottom of the list as top sources of sodium in the diet, – Snack Sense, Sodium:
Based on the fact that most eating a whole foods (little to no processed, prepared, or restaurant foods), you’ll likely want to include salt and based on the autoimmune associations, I’d choose sea or Himalayan salt (and consider the need for some of that added to be iodized given the borderline deficiency for women of child-bearing age).
I actually use non-iodized sea salt for soaking nuts and seeds. See IT’S EASY TO SOAK & DEHYDRATE NUTS for How-To’s. For baking, I use both iodized and non-iodized sea salt including Himalayan, but consider your own dietary iodine loading from iodine rich whole foods and supplements (i.e. multivitamin).
Make certain you read the research and educate yourself about your own situation relative to sodium and iodine dietary intake, and as always, speak with your doctor. Again, I am only increasing awareness, not making health care recommendations or advice.
Sidebar: I am not aware of any studies looking at impact of oral ingestion of sea salt on any disease, high blood pressure, or stroke. Studies to date use highly refined mineral-less table salt. I am only aware of pubmed studies showing the anti-inflammatory nature of sea salt in topical applications and oral health:
- 2005 Bathing in a magnesium-rich Dead Sea salt solution improves skin barrier function, enhances skin hydration, and reduces inflammation in atopic dry skin,
- 2011 Anti-inflammatory Effects of Topical Formulations Containing Sea Silt and Sea Salt on Human Skin In Vivo During Cutaneous Microdialysis and
- 2013 Purple bamboo salt has anticancer activity in TCA8113 cells in vitro and preventive effects on buccal mucosa cancer in mice in vivo.
In health and awareness,
Last updated: February 15, 2017 at 17:40 pm The ‘Summary’ opener was re-written for easier reading and SEO was further optimized. The prior update September 24, 2016 was for SEO optimization.