A comprehensive guide to salt

“The salt of the earth.” “Worth one’s salt.” “Salt away” savings. These age-old expressions illustrate the value humans have placed on salt for eons.

More recently, however, salt has gone from something treasured to something feared. Health authorities have been encouraging us for more than two decades to cut back on this once-prized substance, especially for lowering blood pressure and decreasing heart disease risk.

But are low-sodium diets necessary — or even safe — for everyone? Read on to learn more about salt and how much of it we should be eating, based on the best current evidence.

Disclaimer: Most health authorities currently recommend limiting salt intake. However, the evidence for this is still inconclusive, with no proven benefit beyond lowering blood pressure, and potential harm demonstrated for some people.1
Of note, people who eat a low-carb or keto diet may have an increased need of salt (). At the same time these diets may lower blood pressure, likely reducing any benefit of salt restriction.2 It is thus possible that people eating a low-carb diet may benefit from a higher salt intake than other people.

This guide is written for adults eating a low-carb diet and who are concerned about salt intake and health.

Discuss any lifestyle changes with your doctor. Full disclaimer



1. What is salt?

When you hear the word “salt,” you probably picture a typical salt shaker filled with the white, crystalline substance that’s added to food for seasoning purposes. Originating from seawater, evaporated lakes, or mines deep beneath the earth, salt not only brings out flavors in foods, it’s also used as a preservative and plays an important role in curing, smoking, pickling, and processing food.

For centuries, salt was a precious commodity that was traded for gold. In fact, the term “salary” comes from salarium, the Latin word for salt.

Salt vs. sodium: What’s the difference?

Although frequently used interchangeably, salt and sodium aren’t the same thing — an important distinction when discussing daily intake. Sodium is a mineral that is found naturally in small amounts in many foods such as meat, milk, yogurt, certain tropical fruits, and vegetables like artichokes, celery, beets, and seaweed.

Salt is actually sodium combined with chloride, another mineral. Since sodium chloride is roughly 40% sodium, 5 grams of salt (about 1 teaspoon) contains about 2 grams of sodium. According to one study, salt added to processed foods accounts for about 70% of our daily sodium intake.3

Some sodium also comes from baking soda (sodium bicarbonate) in baked goods, crackers and cookies.

In short, sodium is the essential mineral our body uses, but salt (sodium chloride) is the dominant way we take that mineral in.

Different types of salt

Salt is found on every continent, and edible forms are available in dozens of varieties. Here are a few of the most popular:

  • Table salt: Known as rock salt, or halite, it is mined from underground deposits resulting from the evaporation of ancient seas. Rock salt can be used for curing meat or pulverized to a fine texture to create table salt. To prevent goiter and other problems caused by iodine deficiency, manufacturers typically add iodine and label their salt as iodized.
  • Sea salt: Coarser-grained, flakier, and more subtly flavored than table salt, sea salt comes from evaporated present-day seawater. It may sometimes contain natural traces of iodine.
  • Himalayan salt: Harvested from salt caves in the Himalayan mountains of Pakistan, this colorful salt ranges from off-white to deep pink and contains miniscule amounts of trace minerals despite common claims for larger amounts.
  • Kosher salt: Its large size and coarse texture is used in the koshering process to draw fluids out of meat. Kosher salt is never iodized.

Although some forms are less processed than others and differ slightly in taste and trace mineral content, from a nutritional point of view, salt is salt, or sodium chloride (NaCl). Most salt substitutes are a mix of sodium chloride and potassium chloride (KCL).


2. Why do we need salt?

Sodium is an essential nutrient that must come from your diet because your body can’t make it on its own. As the most concentrated electrolyte in your blood, sodium helps:4

  • maintain the delicate chemical and fluid balance in and around your cells
  • maintain blood pressure
  • contract muscles
  • conduct nerve impulses

Sodium in your body is tightly regulated by your kidneys, central nervous system, and adrenal glands.5 When blood sodium levels rise too high, your brain responds by making you thirsty, prompting you to drink more water so the excess sodium can be excreted in urine.

If you eat too little salt, your adrenal glands release more aldosterone, a hormone that prompts your kidneys to retain sodium. However, this can have adverse effects on other hormones and potassium levels as your body makes adjustments in order to stay balanced and stable at all times.

The sodium your body loses through urine and sweat must be replaced. This amount can vary considerably from day-to-day depending on weather, the intensity and duration of any physical activity performed, how much water you have consumed, your overall state of health, and other factors.

Indeed, drinking far too much water without replacing lost sodium can have devastating consequences. Hyponatremia is an potentially dangerous condition in which there is too little sodium in the bloodstream. Symptoms of hyponatremia include headache, weakness, vertigo, muscle spasms, nausea and vomiting.

Although it’s often triggered by certain medications or an underlying illness, hyponatremia can also occur due to overhydration (“water intoxication”) and inadequate sodium repletion during exercise, especially in hot weather, or in elderly adults who consume low-sodium, restrictive diets.6


3.The controversy over salt intake

What is a “healthy” daily sodium intake? It seems like a simple question, yet it’s one that’s generated quite a bit of controversy over the past several decades.

According to major health organizations in the US and Europe, nearly all of us consume too much sodium on a regular basis, mainly from processed foods.7 They recommend that we sharply reduce our sodium consumption in order to prevent high blood pressure and decrease the risk of heart disease and kidney disease, down to the equivalent of just 1 teaspoon a day.

  • For instance, the 2015-2020 Dietary Guidelines for Americans specify that people should eat no more than 2.3 grams (2,300 mg) of sodium per day — the equivalent of about 1 teaspoon.
  • The American Heart Association goes even further, saying that everyone should ideally consume less than 1,500 mg of sodium (approximately ¾ of a teaspoon) daily. Most people would consume that much by just eating a bowl of soup or a Caesar salad.
  • The World Health Organization (WHO) recommends that we cap our salt intake at 5 grams of salt per day, which at first glance seems quite a bit higher than the amounts above. However, remember that salt is only 40% sodium. Therefore, the WHO’s guidelines actually call for limiting sodium to 2,000 mg per day.
However, these recommendations have been publicly criticized by several researchers and physicians with expertise in the field of nutrition.8

Ketogenic diet expert Stephen Phinney, MD, stated in a recent Virta Health blog post: “[S]odium restriction as a national policy is increasingly apparent as a house built on sand.”

Other experts have also been saying that too-low sodium intake may have unintended adverse health consequences.9 Let’s dive deeper into this controversy, by reviewing the evidence.

Traditional glass salt cellar

The salt guidelines are too restrictive, say experts

News Is it really necessary to lower your salt intake as much as the current guidelines advise, in order to lower your blood pressure? According to a new expert paper, the guidelines are way too restrictive and not based on enough evidence.


4.Research on salt intake in healthy adults

Is there any evidence that following a low-sodium diet, when healthy, can help decrease your risk of developing future chronic disease? The answer may surprise you.

Systematic reviews and meta-analyses of randomized controlled trials (RCTs) — considered the strongest type of evidence — have found variable results. Many haven’t found that sodium restriction reduces heart disease risk in healthy people with normal blood pressure.10

A 2014 Cochrane review likewise found no increased mortality risk with high sodium intake, and found inconsistent to minimal increased cardiovascular disease risk.11 That is in contrast to another review of RCTs that found reduced salt intake did improve all-cause mortality and cardiovascular mortality.12 The inconsistent data makes it difficult to draw strong conclusions, and makes definitive recommendations to lower sodium intake suspect for the general population.

Part of the concern is understanding the baseline diet. For instance, would the small cardiovascular benefit seen in the RCTs have been different if people instead ate a low carb, real-foods diet? We don’t have the answer to that based on RCTs.

Observational studies, a lower level of evidence, show no evidence that higher sodium intake increases the risk of future cardiovascular disease in those currently without the disease. Again, we unfortunately need more information about the quality of the underlying diets they ate.13

Could limiting salt actually harm healthy individuals? One group of researchers who conducted a review of both observational studies and RCTs concluded that sodium restriction has no detrimental effects in healthy people and could potentially benefit some people. Therefore, they feel a low-salt diet is advisable for all.14

However, this finding was questioned by the recent PURE study, which reviewed data on sodium intake from over 100,000 people living in 17 countries. In looking at the relationship between health habits and disease risk, researchers in the PURE study found that although consuming more than 7,000 mg of sodium per day was associated with increased risk of heart attack and death in people with hypertension (sustained elevated blood pressure), getting less than 3,000 mg of sodium per day was also linked to an increased CVD risk in both people with hypertension and those with normal blood pressure.15

In earlier analyses by the same researchers consuming between 3 and 6 grams of sodium daily was linked to the lowest risk of heart disease and early death.16

While observational data like this cannot prove that sodium intake is either a risk factor or a protective factor for heart disease it does suggest that diets with 3 to 6 gram of salt a day could be part of a healthy lifestyle. For more discussion about this, listen to cardiologist Dr. Bret Scher discuss the PURE study findings with its principal investigator Professor Andrew Mente.

 
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Other experts have suggested that blanket low-sodium recommendations may have unintended health consequences in many people.17This includes increased insulin resistance, which has been shown in several salt restriction trials in healthy adults.18 As discussed previously, sodium restriction signals the adrenal glands to release aldosterone, prompting the kidneys to hold on to sodium. Researchers have suggested that these higher aldosterone levels coupled with release of the stress hormone noradrenaline may be responsible for decreased insulin sensitivity in people who follow low-salt diets.19

In 2017, a coalition of three European health organizations recommended an upper limit of 5,000 mg of sodium per day for most people — more than twice as much as the 2,300 mg guidelines that come from other major health organizations.20

As you can see, the data on salt is far from unanimous. How do we sum it up? The highest level of evidence, reviews of RCTs, shows a small increased risk of cardiovascular mortality with higher salt diets. Thus, when following a standard Western diet, it seems a good idea to limit salt intake. Would this also apply to real-food, low-carb diets? That is unknown, and we will address that further in the next section.


5. People on keto or low-carb diets may need additional salt

As we’ve noted in other posts on Diet Doctor, when you follow a low-carb or keto diet, your sodium needs increase — especially initially — as a result of changes in the way your kidneys handle sodium.

With decreased carb intake, insulin levels fall significantly. It’s been known for decades that when insulin levels drop, the kidneys excrete more sodium and water, although the exact mechanism isn’t clear.21

If sodium isn’t replaced, you’re likely to develop the unpleasant symptoms of “keto flu,” which include headache, fatigue, and weakness.

What’s more, a keto or low-carb diet composed of mainly whole foods doesn’t have a lot of sodium to begin with, especially compared to processed foods. Thus you may want to add more salt, to avoid side effects.

How can we reconcile advising increased salt intake when we just mentioned RCTs showing mortality benefit with salt reduction? This is where we need to consider the subtle nuances of studies.

In a standard Western diet, much of the sodium comes from processed foods. Thus reducing it is clearly a beneficial approach. On a low carb, real foods diet, however, we believe that we respond differently to salt. Since we don’t have long term data showing safety, we are cautious in our recommendation to increase salt intake, especially for those with underlying medical conditions. See our section below for more information on co-existing medical issues.

Ways to increase salt intake – more info

Consuming about 4,000 to 7,000 milligrams of sodium (about 2 to 3 teaspoons of salt) is usually sufficient to get through keto-adaptation and can often be maintained beyond the transition period, depending on individual needs.

Here are a few ways to boost sodium intake. However, if you have elevated blood pressure, kidney disease or congestive heart failure, talk to your doctor first before increasing your sodium intake, especially if you take medication.

  • Drink 1 or more cups of salty broth every day
  • Add 1-2 teaspoons of salt in daily food preparation or at the table
  • Eat olives, pickles, sauerkraut, and other salty keto foods regularly
  • Choose standard rather than “low-sodium” sauces and seasonings for cooking
  • Shake salt into a glass of water a couple of times a day.


6. What about salt intake in people with medical conditions?

It appears that healthy people following a Western diet may benefit from lowering salt intake, although observational data paints a different story. Surely there must be good research conclusively supporting the low sodium recommendations for people with chronic disease?

In truth, much of the evidence has been contradictory or inconclusive.

As we mentioned above, all of the research on sodium’s effects has been conducted in people eating standard American diets or low-fat diets rather than low-carb or ketogenic diets. That means most of the salt likely came from processed high carbohydrate food, not from real foods like meats and vegetables with added sea salt. We are not aware of any high-quality evidence that compares salt restriction on its own to carb restriction for improvements in health conditions.

And we do know that high-quality evidence has repeatedly demonstrated that low-carb and ketogenic diets — without salt restriction — can help reduce elevated blood pressure, waist circumference, and high blood sugar and insulin levels.22

Thus we have to question if we are better off restricting the sugar and carbs, not the salt, if we want to really improve these conditions.

Let’s take a closer look at the mostly weak research evidence for salt restriction as it relates to common chronic diseases:

Hypertension

Hypertension is the medical term for high blood pressure. It currently affects one in three people and is especially common in older, overweight or obese individuals. See our guides on high blood pressure and what you can do about it for more information.

Everyone’s blood pressure increases during physical activity and stressful situations. This is normal and poses no harm as long as blood pressure quickly returns to a healthy range. However, blood pressure that remains elevated throughout the day can damage your arteries and increase the risk of heart attack, stroke, kidney disease, loss of vision, and other serious medical problems.

People with hypertension are usually put on medication and advised to minimize salt intake based on several old studies suggesting that higher sodium intake may raise blood pressure.23

Is there overwhelming evidence that salt restriction significantly lowers blood pressure for everyone? No, not really, for a few reasons:

  • Not everyone is salt sensitive. First off, consuming a lot of sodium doesn’t significantly raise blood pressure in everyone, including those with hypertension. A person whose blood pressure increases after eating salt is said to have “salt-sensitive hypertension” due to a combination of genetic and environmental influences on the complex systems that regulate the body’s sodium balance.24 It’s estimated that about 50% of those with hypertension and 25% of individuals with normal baseline blood pressure are salt sensitive, meaning their blood pressure increases by at least 5 points when following a high-sodium diet compared to a low-sodium diet.25Therefore, about half of all people with hypertension do not respond to higher sodium intake with a significant rise in blood pressure and do not respond, as discussed next, with significantly lower blood pressure to lowering salt intake.
  • Reducing sodium intake only slightly decreases blood pressure. Systematic reviews and meta-analyses of trials have found that for most hypertensive adults, sodium restriction doesn’t lead to a dramatic decrease in blood pressure.26 In practical terms, going from 3,500 mg to 1,500 mg of sodium per day might reduce blood pressure by an average of 5 points. Although this modest change may be viewed as a statistically significant reduction in risk by researchers, people might find it not very rewarding as a result, when such severe sodium restriction is very difficult to do and hard to sustain long term.

    Could this small reduction in blood pressure explain the small reduction in cardiovascular mortality seen in two meta-analyses of RCTs? It is possible. It is also possible that the smaller percentage of people who are salt sensitive had a greater effect, and thus saw an improvement in mortality. Unfortunately the data do not specify with this degree of detail.

  • Sodium restriction may have adverse effects. Furthermore, cutting back on salt may have a negative impact on other health markers in hypertensive adults. In a very large review of 185 clinical studies, people with hypertension who followed a sodium-restricted diet for two or more weeks experienced a 3.5% decrease in blood pressure, on average.27

    However, this came at the expense of an increase in triglycerides and in the adrenal hormones aldosterone, adrenaline and noradrenaline, which could potentially lead to health problems over time. Noting the study’s short time frame the authors concluded: “we do not know if low-salt diets improve or worsen health outcomes.” What’s more, the response to sodium restriction in hypertensive individuals seems to include increased insulin resistance, regardless of whether they are salt sensitive or not.28 Thus, rather than simply measuring small changes in blood pressure, what we really need to know is if long-term health outcomes improve or not. Unfortunately, we don’t have that data.

  • Overall diet may affect blood pressure as much as salt does. Other researchers have suggested that rather than restricting sodium intake, those who are salt sensitive should be provided with tools to improve the quality of their diet, promote weight loss and decrease insulin resistance, which could help make them less salt sensitive and reduce their disease risk.29 A very-low-carbohydrate, ketogenic diet may significantly decrease blood pressure in those who are overweight or have metabolic syndrome regardless of sodium content.30
Blodtryck-BloodPressure-square

How to normalize your blood pressure

GuideElevated blood pressure is a common health issue today. Almost a third of U.S. adults have high blood pressure – perhaps you or someone in your family does? High blood pressure isn’t necessarily something you can feel, but it increases the risk of serious conditions such as strokes and heart attacks.

Heart disease

Heart disease, also known as cardiovascular disease (CVD), is a broad term that includes several disorders. People with CVD are generally advised to reduce their salt consumption as part of a “heart healthy diet,” but here is what the research evidence actually has found:

  • Atherosclerosis: The most common type of cardiovascular disease is coronary artery disease due to atherosclerosis, a process in which plaque builds up in the walls of the arteries, restricts blood flow, and increases heart attack risk.

    A recent systematic review and meta-analysis of 11 randomized controlled trials (RCTs) concluded that reducing sodium by an average of 3,000 mg per day improved arterial elasticity in people with hypertension, heart disease, diabetes, obesity, or no health issues.31

    However, with the exception of one study in 169 hypertensive individuals, the studies were fairly small (between 6 and 40 participants), lasted only one to six weeks, and provided no data on clinical outcomes such as heart attacks and strokes. Therefore, the long-term effects of sodium restriction on arterial health are yet to be determined. By contrast, several large observational studies have found that very low sodium intake is associated with worse cardiovascular outcomes.32

    While this is associational data, the study authors hypothesize that it is due to the hormonal alterations in aldosterone and adrenaline discussed previously.

  • Congestive heart failure: In congestive heart failure (CHF), another common disorder, the heart’s ability to pump blood is impaired, leading to fluid buildup in the lungs and extremities. Individuals with CHF are usually told to minimize sodium intake in order to prevent fluid overload.

    However, no strong research evidence exists suggesting that severe sodium restriction is the best strategy for CHF.

    Indeed, some in the medical community are rethinking whether patients with CHF benefit from very-low-sodium diets.33

    In 2018, researchers performed a systematic review and analysis of nine RCTs and concluded that a lack of high-quality evidence exists in support of current low-sodium guidelines for CHF.34

    Based on the inconsistent results across the studies, it’s possible that some people may be more sensitive to sodium’s fluid-retaining effects than others. Although more research is needed, individualized sodium recommendations may be most appropriate for managing CHF.

Diabetes and prediabetes

At increased risk for both heart and kidney disease, people with diabetes usually receive advice to limit their salt intake. At one time, the American Diabetes Association recommended that individuals with diabetes aim for less than 1,500 mg of sodium per day; however, this was modified to 2,300 mg per day in the 2019 Standards of Care in Diabetes based on the lack of evidence supporting a further restriction.

Overall, the evidence to date seems to suggest that salt restriction doesn’t improve diabetes outcomes.

  • Observational studies suggest potential increase in heart disease and mortality risk. One 2011 study found that people with type 2 diabetes who consumed the least sodium had an increased risk of early death from heart disease or other causes compared to those who consumed the most sodium.35 Another 2011 study in people with type 1 diabetes reported that both the highest and lowest intakes of sodium were linked to an increased risk of early death and developing kidney disease.36
  • Experimental study outcomes are mixed. Of the few RCTs available, some have found that sodium restriction may lead to small improvements in blood pressure and kidney function in people with type 2 diabetes.37 High-quality research on salt restriction in type 1 diabetes is even more scarce, but two small studies suggest that restricting salt may have adverse effects on kidney health.38 Although a large meta-analysis of RCTs in people with type 1 and type 2 diabetes found that sodium restriction helped reduce blood pressure, the largest effects were seen in people with normal blood pressure, for whom further blood pressure reduction might be of limited or no value.39
  • Health risks of high sodium intake may depend on blood sugar control. One study in Japanese men with type 2 diabetes did find an association between higher sodium intakes and greater heart disease risk, but this only applied to those with extremely poor diabetes control (HbA1c of 9% or greater); no relationship was found between high salt intake and CVD in those with lower HbA1c’s.40
  • Increased insulin resistance: Additionally, recent as well as older controlled studies have found that eating too little salt may worsen insulin resistance in adults with type 2 diabetes or exacerbate impaired glucose tolerance in people with prediabetes.41

    Remember that sodium restriction may interfere with the body’s normal system of blood pressure regulation. It’s believed that low sodium intake triggers the adrenal glands to release aldosterone and noradrenaline, which may lead to reduced insulin sensitivity.42

In short, while avoiding very high sodium intakes greater than 6 grams a day may be beneficial for people with diabetes who have salt-sensitive hypertension, severe sodium restriction in everyone else with diabetes might end up doing more harm than good.

Kidney disease

When functioning properly, your kidneys reabsorb water, sodium and other nutrients from your blood as needed and excrete whatever isn’t needed into your urine.

In chronic kidney disease, the kidneys become less efficient at eliminating excess sodium from the body. Additionally, hypertension is a leading cause of kidney failure because increased blood pressure can damage the delicate arteries that lead to the kidneys. For these reasons, the National Kidney Foundation advises people with kidney disease to limit their sodium intake to less than 2,000 mg per day.

A recent systematic review and analysis of RCTs found that sodium restriction in people with early to end-stage kidney disease can significantly lower blood pressure and reduce urinary albumin.43 Albumin is a protein normally present in blood, and its appearance in urine indicates that the kidneys aren’t functioning the way they should be.

However, the optimal sodium restriction for people with chronic kidney disease isn’t clear. A controlled 4-week study found that the benefits of reducing salt were most pronounced in hypertensive people with kidney disease whose usual diets provided 5,700 mg of sodium per day.44 And an observational study found that consuming more than 4,500 mg of sodium daily was associated with increased risk of CVD, heart attack, and stroke in people with chronic kidney disease. However, a wide range of sodium intakes below this level were all linked to lower risk.45

Therefore, for this group, moderate sodium restriction may be beneficial and easier to sustain than extremely low salt intake. Unfortunately, these studies did not adequately control for the quality of food intake, thus leaving some questions about the applicability to a real-foods, low-carb diet.


7. Is salt the real culprit?

According to health organizations, high amounts of sodium in processed foods have played a major role in the epidemics of heart disease and other cardiometabolic conditions. In addition, analyses of RCTs suggest a benefit from reducing salt consumption.

However, what if it isn’t the sodium but rather the sugar and refined carbs that are responsible for most of the effects of processed food? Unfortunately, the research does not do a great job of teasing this out.

Some researchers have suggested that sugar rather than sodium is the main driving force in hypertension, while others say that it’s actually a combination of sugar and salt.46 However, most studies have a hard time separating overall salt intake from consumption of these potentially unhealthy, high-carbohydrate processed foods.

We know that reducing carbs can lower blood pressure, decrease CVD markers, help reverse diabetes, and promote weight loss — even with moderate to high sodium consumption. So the focus on the sodium content in processed foods alone may be somewhat misleading.


8. Summary: How much salt should you eat?

Both published research and anecdotal evidence have shown that the response to salt intake varies from person to person.

You can test your own blood pressure or look for signs of fluid retention (puffiness, tight rings) the day after you’ve eaten salty foods and compare these results to those following a day of eating less salt. In many cases, fluid retention and elevated blood pressure may be unrelated to sodium intake or only minimally influenced by it.

If you have salt-sensitive hypertension, congestive heart failure, or kidney disease, it may be best to avoid eating a lot of sodium. However, the amount that’s best for you may require some experimentation, in coordination with your medical provider. Also, keep in mind that eating a high-quality, carb-restricted diet may potentially improve blood pressure, cardiovascular function, and kidney health much more than restricting salt.

If you don’t have any of these conditions, there isn’t any convincing evidence that severe sodium restriction is beneficial when following a real-foods, low-carb or keto diet.

Consuming about 4 to 7 grams of sodium (about 2 to 3 teaspoons of salt) per day could be where most people in the low-carb community will feel and perform the best. Occasionally, even more sodium may be needed to replenish increased losses in sweat during hot weather or strenuous physical activity. Just keep in mind that if you have salt sensitive hypertension, you will need to be more cautious than most.

Finally, remember that it’s always excellent advice to replace highly-processed, low-quality food with minimally-processed, nutritious real food.


Comments

  1. A Cochrane meta-analysis of RCTs show no clear benefit:

    Cochrane 2014: Reduced dietary salt for the prevention of cardiovascular disease [strong evidence]

    An earlier Cochrane review found a significantly increased risk of death from salt restriction in people with heart failure:

    American Journal of Hypertension 2011: Reduced dietary salt for the prevention of cardiovascular disease: a meta-analysis of randomized controlled trials (Cochrane review) [strong evidence]

  2. Obesity Reviews 2009: Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities [strong evidence]

  3. Circulation 2017: Sources of sodium in US adults from 3 geographic regions [observational study; very weak evidence]

  4. Electrolytes are minerals that form positive or negative electrical charges when dissolved in blood and other body fluids. The major electrolytes are sodium, potassium, calcium, magnesium, and phosphate. See Diet Doctor guide: Do you need electrolyte supplementation on a keto diet

  5. American Journal of Physiology 2003: Body sodium and volume homeostasis [overview article, ungraded]

  6. Scandinavian Journal of Medicine and Science in Sports 2017: Restricting dietary sodium reduces plasma sodium response to exercise in the heat [randomized controlled trial; moderate evidence]

    Military Medicine 2018: Collapse in the heat – from overhydration to the emergency room – three cases of exercise-associated hyponatremia associated with exertional heat illness [case study series; weak evidence]

  7. Surveys show that adults in the US consume about 3-4 grams of sodium per day, on average, with almost 90% eating more than the recommended amounts.

    CDC 2016: Prevalence of Excess Sodium Intake in the United States — NHANES, 2009–2012

  8. QJM: Monthly Journal of the Association of Physicians 2011: Should we now abandon the low-salt diet? [commentary; no evidence]

  9. The salt guidelines are too restrictive, say experts

  10. Journal of the American Medical Association 1996: Effect of reduced dietary sodium on blood pressure: a meta-analysis of randomized controlled trials [strong evidence]

    American Journal of Hypertension 2011: Reduced dietary salt for the prevention of cardiovascular disease: a meta-analysis of randomized controlled trials (Cochrane review) [strong evidence]

  11. Cochrane Database of Systematic Reviews 2014: Reduced dietary salt for the prevention of cardiovascular disease [systematic review of RCTs; strong evidence]

  12. Annals of Internal Medicine 2019: Effects of nutritional supplements and dietary interventions on cardiovascular outcomes: An umbrella review and evidence map [systematic review of RCTs; strong evidence]

  13. Journal of the American Medical Associatiom 2011: Fatal and nonfatal outcomes, incidence of hypertension, and blood pressure changes in relation to urinary sodium excretion [observational study with HR < 2; very weak evidence]

  14. The British Medical Journal 2013: Effect of lower sodium intake on health: systematic review and meta-analyses [moderate evidence]

  15. The Lancet 2016: Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies [observational study with HR < 2; very weak evidence]

  16. The New England Journal of Medicine 2014: Urinary sodium and potassium excretion, mortality, and cardiovascular events [observational study with HR < 2; very weak evidence]

    Journal of the American Medical Association 2011: Urinary sodium and potassium excretion and risk of cardiovascular events [observational study with HR < 2; very weak evidence]

  17. The American Journal of Medicine 2013: Dietary sodium restriction: take it with a grain of salt [commentary; no evidence]

    Journal of Nutritional Science and Vitaminology 2018: Dietary salt (sodium chloride) requirement and adverse effects of salt restriction in humans [non-controlled trial; weak evidence]

  18. Metabolism 2011: Low-salt diet increases insulin resistance in healthy subjects [randomized controlled trial; moderate evidence]

    Clinical Science 2007: Salt intake and insulin sensitivity in healthy human volunteers [non-controlled trial; weak evidence]

    Clinical Science 2003: Decreased insulin sensitivity during dietary sodium restriction is not mediated by effects of angiotensin II on insulin action [randomized trial; moderate evidence]

  19. Clinical Science 2007: Salt intake and insulin sensitivity in healthy human volunteers [non-controlled trial; weak evidence]

  20. European Heart Journal 2017: The technical report on sodium intake and cardiovascular disease in low- and middle-income countries by the joint working group of the World Heart Federation, the European Society of Hypertension and the European Public Health Association [overview article; ungraded]

  21. American Journal of Physiology. Renal Physiology 2007: Insulin’s impact on renal sodium transport and blood pressure in health, obesity, and diabetes [overview article; ungraded]

    Diabetalogia 1981: The effect of insulin on renal sodium metabolism [overview article; ungraded]

  22. Obesity Reviews 2012: Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors [strong evidence]

    Cardiovascular Diabetology 2018: Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study [non-controlled trial; weak evidence]

  23. Hypertension 2000: National Heart, Lung, and Blood Institute Workshop on Sodium and Blood Pressure: A critical review of current scientific evidence [overview article; ungraded]

    British Medical Journal 1988: Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group [observational study with HR < 2; very weak evidence]

  24. Journal of the American Society of Nephrology 2014: Mechanism of salt-sensitive hypertension: focus on adrenal and sympathetic nervous systems [overview article; ungraded]

    Physiological Genomics 2018: GNAI2 polymorphic variance associates with salt sensitivity of blood pressure in the Genetic Epidemiology Network of Salt Sensitivity study [mechanistic study; ungraded]

  25. Current Opinion in Nephrology and Hypertension 2012: Mechanisms and consequences of salt sensitivity and dietary salt intake [overview article; ungraded]

  26. The British Medical Journal 2002: Systematic review of long-term effects of advice to reduce dietary salt in adults [strong evidence]

    Global Heart 2015: A meta-analysis of dietary salt restriction on blood pressure in Chinese adults [strong evidence]

  27. Cochrane Database of Systematic Reviews 2017: Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride [systematic review of controlled trials; strong evidence]

  28. Hypertension 2014: Effect of low salt diet on insulin resistance in salt-sensitive versus salt-resistant hypertension [randomized controlled trial; moderate evidence]

  29. Journal of the American College of Nutrition 2006: Salt sensitivity, a determinant of blood pressure, cardiovascular disease and survival [overview article; ungraded]

  30. Journal of Medicinal Food 2011: A pilot study of the Spanish Ketogenic Mediterranean Diet: an effective therapy for the metabolic syndrome [non-randomized trial; weak evidence]

    High Blood Pressure and Cardiovascular Prevention 2015: Middle and long-term impact of a very-low-carbohydrate ketogenic diet oncardiometabolic factors; a multi-center, cross-sectional, clinical study [non-randomized trial; weak evidence]

  31. Journal of Hypertension 2018: Effect of dietary sodium restriction on arterial stiffness: systematic review and meta-analysis of the randomized controlled trials [strong evidence]

  32. Journal of the American Directors Association 2018: Association between sodium excretion and cardiovascular disease and mortality in the elderly: a cohort study [observational study with HR < 2; very weak evidence]

    The Lancet 2016: Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies [observational study with HR < 2; very weak evidence]

    Hypertension 1995: Low urinary sodium is associated with greater risk of myocardial infarction among treated hypertensive men [observational study with HR < 2; very weak evidence]

  33. Arquivos Brasileiros de Cardiologia 2010: Is the low-sodium diet actually indicated for all patients with stable heart failure? [randomized controlled trial; moderate evidence]

    JACC. Heart Failure 2016: Impact of dietary sodium restriction on heart failure outcomes [observational study with HR < 2; very weak evidence]

  34. Journal of the American Medical Internal Medicine 2018: Reduced salt intake for heart failure: a systematic review [strong evidence]

  35. Diabetes Care 2011: Dietary salt intake and mortality in patients with type 2 diabetes [observational study with HR < 2; very weak evidence]

  36. Diabetes Care 2011: The association between dietary sodium intake, ESRD, and all-cause mortality in patients with type 1 diabetes [observational study with HR < 2; very weak evidence]

  37. The Lancet 2018: Moderate salt restriction with or without paricalcitol in type 2 diabetes and losartan-resistant macroalbuminuria (PROCEED): a randomised, double-blind, placebo-controlled, crossover trial [moderate evidence]

    Hypertension 2016: Modest salt reduction lowers blood pressure and albumin excretion in impaired glucose tolerance and type 2 diabetes mellitus: a randomized double-blind trial [moderate evidence]

  38. Diabetologia 2002: Short-term moderate sodium restriction induces relative hyperfiltration in normotensive normoalbuminuric Type I diabetes mellitus [randomized trial; moderate evidence]

    Journal of the American Society of Nephrology 1997: Renal responses to sodium restriction in patients with early diabetes mellitus [randomized trial; moderate evidence]

  39. Cochrane Database of Systematic Reviews 2010: Altered dietary salt intake for preventing and treating diabetic kidney disease [sytematic review of randomized controlled trials; strong evidence]

  40. The Journal of Clinical Endocrinology & Metabolism 2014: Dietary sodium intake and incidence of diabetes complications in Japanese patients with type 2 diabetes: analysis of the Japan Diabetes Complications Study (JDCS) [observational study with HR < 2; very weak evidence]

  41. The Journal of Clinical Endocrinology & Metabolism 1998: Dietary sodium restriction impairs insulin sensitivity in noninsulin-dependent diabetes mellitus [randomized trial; moderate evidence]

    American Journal of Hypertension 1999: Moderate dietary salt restriction increases vascular and systemic insulin resistance [randomized trial; moderate evidence]

    Hypertension 2014: Effect of low salt diet on insulin resistance in salt-sensitive versus salt-resistant hypertension [randomized trial; moderate evidence]

    American Journal of Hypertension 1994: Dietary NaCl restriction deteriorates oral glucose tolerance in hypertensive patients with impairment of glucose tolerance [randomized trial; moderate evidence]

  42. Metabolism 2011: Low-salt diet increases insulin resistance in healthy subjects [randomized trial; moderate evidence]

    Clinical Science 2007: Salt intake and insulin sensitivity in healthy human volunteers [observational study; very weak evidence]

  43. Nutrients 2018: Dietary salt restriction in chronic kidney disease: a meta-analysis of randomized clinical trials [strong evidence]

  44. The Medical Journal of Malaysia 2018: Study of low salt diet in hypertensive patients with chronic kidney disease [randomized controlled trial; moderate evidence]

  45. Journal of the American Medical Association 2016: Sodium excretion and the risk of cardiovascular disease in patients with chronic kidney disease [observational study with HR < 2; very weak evidence]

  46. Open Heart 2014: The wrong white crystals: not salt but sugar as aetiological in hypertension and cardiometabolic disease [commentary; no evidence]

    Journal of the American College of Nutrition 2017: Blood pressure regulation: reviewing evidence for interplay between common dietary sugars and table salt [overview article; ungraded]