Electrolyte minerals animate your cells. Are yours out of whack?
Executive Summary
- The human body relies on electrolyte minerals (e.g., sodium, chloride, potassium, magnesium) for muscle contractions, nerve impulses, acid-base balance, and hydration.
- Deficiencies in minerals result in dysfunction, disease and even death.
- Electrolytes balance each other and are balanced by other systems in the body.
- Chronic excess consumption of any has the potential to cause harm.
- Salt (sodium chloride) is an essential mineral; we must get it from the diet.
- Due to sodium’s role in hypertension, salt is the only essential nutrient that has been vilified.
- We have a rich history with salt; it’s central to traditions and cultures across the world.
- UK estimates equal about 8 grams of salt consumed daily.
- Ranges between 5.1 g/d in Samoa and 17.7 g/d in China.
- 75% of a developed country's salt consumption comes from processed foods.
- In the UK, 61% comes from processed foods.
- The Salt Wars have been raging for 120 years.
- Scientists cannot agree on all the variables affecting blood pressure, so they single out sodium.
- Only a third of people’s blood pressure increases with their salt intake.
- This is known as salt sensitivity.
- Salt sensitivity is caused by potassium deficiency, obesity, insulin resistance, specific genes and kidney disease. Excessive fructose consumption also plays a role.
- There is a J-shaped curve (a sweet spot) of salt consumption.
- Many researchers using more accurate data-gathering techniques have found a sweet spot between about 4 and 6 g/d of sodium. That’s 10 - 15 grams of salt daily, twice the recommended amounts.
- The causes of salt sensitivity are the real issue, not salt (within reason).
- Reduce or eliminate junk foods to lower your chances of becoming salt-sensitive and increase your intake of nutrients, including potassium, which is essential for maintaining homeostasis by preventing or reversing salt sensitivity.
- Reducing junk foods, especially sugar, reduces body fat %, improves kidney function, insulin resistance and helps manage ‘bad genes’.
- Heavy sweaters (intense and endurance exercisers), low-carb and keto dieters, and people who make their meals from scratch may need to increase their salt intake and the other balancing minerals, especially potassium.
Introduction
Electrolytes, such as sodium, potassium, calcium, and magnesium, help generate and transmit electrical impulses throughout the body and brain. These impulses are essential for myriad cellular activities, including muscle contractions, nerve impulse transmission, acid-base balance, and hydration. Minerals must stay balanced. Salt (sodium chloride) is a life-giving mineral with a rich history intertwined with the story of us. For over 120 years, scientists have been fighting over salt’s role in human health based on the simple truth that retained sodium increases blood pressure. However, healthy people with balanced electrolyte minerals can efficiently excrete salt to maintain homeostasis. Obesity, kidney disease, insulin resistance and potassium deficiency can all induce a condition called salt sensitivity. About a third of people are salt-sensitive, meaning their blood levels increase with the amount they eat. Public health advice omits these nuances. Their advice is to reduce salt intake without knowing how much an individual consumes. Take control of your health by choosing nutrient-dense foods and using a balanced electrolyte supplement when appropriate. Read the full article to learn more.
We are electrical beings.
Tiny electrical impulses spark communication signals throughout our bodies. Electrolyte minerals provide us with the ions that shoot between cells to animate us from head to toe. They regulate fluid balance, support nerve and muscle function, and help maintain acid-base balance. Without them, we would cease to be. One primary electrolyte mineral, sodium chloride, united as salt, has become infamous for its contribution to increasing blood pressure. Salt’s status as an essential nutrient has all but been forgotten, as health authorities tell the world to reduce, reduce, reduce. As always, public health advice has been simplified to its lowest common denominator, leaving people with the false notion that salt is toxic. But, as always, there are vital nuances for a health-seeking individual to grasp.
Electrolyte 101
What are electrolytes?
Electrolytes are minerals that have an electrical charge.
They include sodium, potassium, chloride, calcium, magnesium, phosphate, and bicarbonate. This article will cover sodium, chloride, potassium, calcium and magnesium. Electrolyte minerals transmit messages through our complex nervous systems. Muscle contractions and relaxations, including our beating hearts and the ebb and flow of blood, require electrical signals. That’s why electric shocks tense our muscles and can make our heart stop or restart. When athletes become depleted in electrolytes, their legs stop working. Water moving in and out of our cells depends on these tiny electrical signals facilitated by those electrolyte minerals. This makes hydration much more complex than just the amount of liquids we drink. Hydration is the story of electrolyte mineral and water balance. If you miss this notion, you can run short of electrolytes when you need them the most. Electrolytes are essential to run your electric body.
Sodium
At the heart of any article on electrolytes will be salt, this one included. Ninety per cent of our sodium comes from salt, which is why the two words have almost become synonymous.[1] Sodium is the most abundant mineral outside of our cells. Without sufficient blood sodium levels, brain cells begin to swell with water. The pressure inside the skull builds, becoming a headache. Nausea sweeps through the body. Without adding sodium, the cells begin to balloon. The afflicted starts to vomit. They become confused before collapsing. If their sodium levels are not increased quickly, they’ll drop into a coma and maybe even die. People die like this every year. Ignorance and fear push them towards the precise thing they’re trying to avoid. People might over-hydrate like this before and during a marathon, often on a sweltering day when their anxiety about dehydration peaks.[2] The irony is that they mistake the early symptoms of overhydration for dehydration and do the opposite of what they should; they drink more water. They’re suffering from hyponatremia, low sodium, a condition that comes about with disease or by drinking too much water in a short space of time, thereby lowering the blood levels of sodium beyond a safe level. Simple equations applied to us all, black-and-white guidelines, underlying conditions and fear have combined to make sodium, from salt, public enemy number one.
Chloride
Chloride works hard to balance sodium, potassium and water within our cells, making it a major player in hydration. Approximately 75% to 80% of our dietary chloride intake comes from salt, particularly in Western countries.[3] This often-forgotten electrolyte mineral helps to keep acid-base balance in our blood. In this role, chloride helps transport carbon dioxide through the blood for exhalation by the lungs. Chloride synthesises stomach acid, an essential first-line defence system and critical digestive cog. Similar to the other electrolytes, chloride also plays a part in nerve impulse transmission and muscle contraction.[4] A deficiency in chloride is rare, usually only seen during prolonged illnesses. It brings about fatigue, muscle cramps, cognitive issues, and difficulties with digestion and breathing before culminating in serious cardiovascular events.[5] Babies became seriously underweight and ill because of a chloride deficiency.[6]
Potassium
Potassium is the most abundant mineral inside our cells, involved in over 600 enzymatic reactions.[7] Without sufficient potassium, muscles begin to weaken and cramp. Heartbeats become irregular and frightening, something called arrhythmia. Fatigue sweeps through the body as it runs out of this electrical substrate. High blood pressure manifests and can become dangerous. Gut muscle contractions slow, and constipation results. Severe potassium deficiency, known as hypokalaemia, eventually leads to paralysis and, if left untreated, to cardiac arrest. Good whole food sources include green leafy veg, salmon, avocado, dairy milk (not the chocolate!), potatoes, bananas, mushrooms, halibut, tuna, shellfish, squash and others.
Magnesium
Without sufficient magnesium, myriad symptoms arise.
Runner up to potassium, magnesium is the second most abundant mineral inside our cells. Magnesium is involved in over 600 enzymatic reactions and counting.[8] A mild deficiency can trigger minute muscle ticks, fatigue and headaches, to name a few.[9] As a deficiency worsens, symptom severity increases. Ticks become cramps; fatigue becomes debilitating; headaches become splitting, ushering in crushing anxiety, insomnia, and emotions that roller coaster up and down at random. Chronic stress, often normalised these days, drains people of their magnesium, trapping them in a vicious cycle of using more at the same time as needing more.[10] If we don’t get bogged down with the bioavailability issues, good sources include nuts, seeds, legumes, green leafy vegetables, yoghurt, halibut, salmon and other whole foods.
Calcium
Calcium plays critical roles both inside and outside of cells.
Without sufficient calcium, symptoms similar to magnesium deficiency start cropping up. Muscle cramps, tingling in the fingers and lethargy can go unnoticed, ignored or covered with cups of sugary coffee. As the deficiency progresses, symptoms become more pronounced, leading to muscle spasms, difficulty swallowing, and heart palpitations. Chronic calcium deficiency eats away at bones and teeth as the body seizes it from those places to more immediately life-threatening areas, including the heart, brain and nervous system.[11] Irritability, depression, confusion, and abnormal heart rhythms begin to manifest. When it comes to electrolyte minerals, balance is life. Good sources include all dairy products, canned fish with bones, leafy green vegetables, nuts, seeds and other whole foods.
The delicate interplay between electrolyte minerals
The body is constantly seeking homeostasis, the scientific term for balance.
Our amazing bodies endlessly monitor our systems and adjust to keep everything in homeostasis. Minerals are instrumental to achieving this balance but must themselves be in balance. In other words, you can’t just take loads of one or two minerals without upsetting the equilibrium of the others, like worsening the sound quality when amping up a single frequency on a '90s Hi-Fi system. Eating natural whole foods alone makes reaching harmful levels of minerals almost impossible, but supplements need a little know-how and, therefore, come with directions. In theory, if you consume too many electrolyte minerals, which dissolve in water, your kidneys can remove them in urine, provided you're well-hydrated and don't have any health conditions that could hinder this process. In reality, the chronic excessive consumption of any electrolyte upsets the delicate mineral balance and can potentially cause harm.
For example, high sodium intake can lead to potassium depletion and vice versa. Excess magnesium can decrease calcium levels.[12] The reverse is also true.[13] High sodium levels can also increase the excretion of calcium.[14] Potassium can shield calcium from excess sodium.[15] Low magnesium levels also drag potassium levels down with them.[16] Sodium and chloride (salt) work closely to balance minerals and water. The point is minerals are constantly jockeying with each other as the body tries to maintain homeostasis.
Doctors received a stark reminder of this balancing act after a new enteral (tube feeding) nutrition product turned out to be deficient in chloride. Unaware, doctors gave 59 severely disabled patients the new enteral food product. After about eight weeks, patients became deficient in not only chloride but also sodium and potassium, despite them being within the product.[17]
Now, let’s take a deep dive into salt.
Salt & the real issue
‘Salt is one of the cornerstones on which the mammalian biochemical structure is built. Total exclusion of salt from the diet leads to disaster, namely death. Still, salt is considered by some authorities to be toxic on a level comparable with alcohol and tobacco. Why is salt the only essential component of mammals to have obtained this unattractive status?’ [18]
Niels Graudal MD; Salt Research Scientist.
Salt’s appeal as a condiment is its ability to cancel out bitterness whilst simultaneously allowing sweet and sour flavours to pop. By decreasing water activity, salt concentrates flavour and heightens our pleasure from food. People added salt to their food at least 40,000 years ago and have used it to ferment plants and preserve meat ever since.[19] In China, 8000 years ago, salt farmers would scoop it from shallow pools at the end of a sunny day before it trundled off across the vast countryside.[20] Salt mining is an ancient industry, the oldest mine yet discovered, in Hallstatt, Austria, dates back 6000 years.[21] Salted and fermented seafood and meat were favourites among the Ancient Egyptians, immortalised along with the Pharaohs in their tomb murals.[22] Roman legionaries spent a part of their salaries on salt. Indeed, the Latin word for salt is ‘sal’, the root of the word salary.[23] Pliny the Elder, an ancient Roman author, remarked that ‘Civilised life cannot proceed without salt: it is so necessary an ingredient that it has become a metaphor for intense mental pleasure.’[24] The Romans were not unique; salt and their famous salty fermented fish sauce, Garum, were traded all over the ancient world.[25] In Venice, a busy port between the 14th and 16th centuries, 30-60% of the import cargo was salt.[26] Certainly, salt has been a sought-after commodity, like sugar, but it has a life-giving role to play.
How much salt did we eat?
There is a current trend to look back at what pre-humans ate during their evolution towards becoming modern humans about 300,000 years ago. The idea is that those things we ate in abundance all those millennia ago are an excellent evolutionary fit for us today, which makes sense. For example, there are vast amounts of archaeological data showing that red meat, indeed anything that moved large and small, fell foul of our ancestors' flinty attacks and made up a large proportion of their diets.[27] However, whether they ate salt similarly is infinitely more challenging to prove. Two researchers attempted to work out how much sodium our Palaeolithic ancestors ate.
The paper, published in the New England Journal of Medicine back in 1985, stated that ancient humans between 2 million years ago and 10,000 years ago ate about 700 mg of sodium per day.[28]
That’s about 1780 mg of salt, or about a third of a teaspoon of typical table salt. That’s low compared to today. James DiNicolantonio, a cardiovascular research scientist, writes about where the researchers' palaeolithic estimates went wrong in his book ‘The Salt Fix: Why the Experts Got it All Wrong and How Eating More Might Save Your Life’.[29] They calculated this low number using only muscle meat from land animals and certain plants, DiNicolantonio explains. They missed all of the aquatic animals.[30] Shellfish are very high in sodium[31], and our early ancestors ate a lot of them if the piles of archaeological evidence still in existence are anything to go by.[32] Other food sources, especially organs and blood, were also omitted in their calculations. Meat only contains a little sodium, but blood is an excellent source. To this day, the Maasai tribe in Kenya drink their cattle’s blood. Perhaps this sacred and completely normalised tribal tradition began as a salt-seeking behaviour.[33]
However, a look at existing hunter-gatherers shows a relatively low intake of salt, with the Yanomamo Indians (Brazil) eating just 0.1 grams daily—if this is accurate, that means they’re not consuming enough sodium to live—compared to the Alaskan Eskimos at the other end of the scale eating 3.91 grams daily.[34] Across groups, the average is just 1000 mg of sodium per day.
There is isotopic evidence of an increase in salt consumption during ancient Greece and Roman times, but whether this affected their health is impossible to prove.[35] In Mark Kurlansky’s best-seller, Salt: A World History, he writes, ‘The salt intake of Europeans, much of it in the form of salted fish, rose from forty grams a day per person in the sixteenth century to seventy grams in the eighteenth century’ (emphasis added).[36] In The Salt Fix, DiNicolantonio makes the case that heart disease was virtually unheard of until the early 20th century, yet people were eating much more salt.[37] While hunting high and low during the research for this article, we didn't find any supporting evidence to equal this kind of salt intake and asked Kurlansky’s publisher for their source. We’re waiting for a response. Suffice it to say we don’t know how much salt our ancestors ate, and from an evolutionary standpoint, what they ate a few hundred or even a few thousand years ago makes no difference to us.
How much salt are we eating nowadays?
Today, in the UK, we eat between about 7 and 8 grams of salt daily, depending on the data you look at.[38] That’s between 1.2 and 1.4 teaspoons. Globally, the range of salt eating is broad, ranging from 5.1 grams per day in Samoa to 17.7 in China.[39] There are accuracy issues with this data because estimates are dependent on substantial observational studies that use food frequency questionnaires (FFQs).[40] People receive an FFQ through the post and tick boxes about their diet and lifestyle.[41] But our memories are deeply flawed; we forget the fudge sundae we ate five minutes ago, exaggerate, and lie all the time, often without knowing it.[42] These perfectly normal human behaviours would suggest that recorded intakes are probably lower than actual consumption because we underreport the processed foods we eat.[43] In developed countries, 75% of salt consumption comes from packaged processed foods, we add 15% at home during cooking, and 10% is the natural sodium content in foods.[44] In the UK, we get 61% of our salt from processed foods (see the pie chart below).
Any discussion about excessive salt consumption should focus on packaged processed foods. Cereal and cereal products add the most salt to the Great British diet, with bread leading the way.[46] Surprised?
Suppose someone is eating 8 grams of salt per day. In that case, 61% comes from processed foods, 21% of the sodium is present in the food, and 18% of the salt is added during cooking or at the table (discretionary salt). It’s not hard to think of an effective intervention to lower their salt intake. If they stop eating processed foods, that number drops to a smidge over 3 grams of salt per day; 1.3 grams of sodium. In reality, those numbers don’t work like that because eliminated processed meals will be replaced with something else with natural sodium and discretionary salt added at a rate of approximately 21% and 18%, respectively. But, the point is if people really are overeating salt, which is highly individualised and contentious, they can quickly lower it by kicking processed foods to the curb. We’ll discuss who might need to eat more salt later in the article.
The problem with public health advice
Health authorities around the globe advise we all keep our sodium between 1.5 - 2.3 grams per day. That’s about four to six grams of salt; six is about a teaspoon. [47] That’s a 53% difference in range. This lack of consensus tells us that a sweet spot still eludes us, at least from the perspective of public health advice. H.L. Mencken, an American journalist in the early 20th century, well-known for his sharp wit and scathing social commentary, said, ‘For every complex problem, there is an answer that is clear, simple, and wrong.’ The statement, ‘salt increases blood pressure,’ is beautifully clear and simple. It’s also wrong. Salt only increases blood pressure in salt-sensitive people. This message is central to this article. But, when it comes to public health messaging, you can forget nuances of any kind. Directions to the masses have to be black and white. Grey areas are confusing, and confused people stop doing as they’re told. Eat less; move more. Salt is bad; lower it.
Why are we so frightened of salt?
Why has salt obtained an ‘unattractive status’?
After all, our blood, sweat and tears are full of salt. Without salt, we sicken and die. In healthy people, about 0.4% of their weight is salt. That means the average person carries around 43 teaspoons of salt mainly in their blood.[48] Salt has an unattractive status because of sodium's controversial role in hypertension. Higher levels of retained sodium in the blood pull more water into the circulatory system, increasing its volume and, therefore, the pressure.[49] Hypertension, commonly known as high blood pressure, is a chronic medical condition where the force exerted by blood against artery walls is consistently too high. This condition can lead to serious health issues, including heart disease, stroke, and kidney problems. Blood pressure is measured in millimetres of mercury (mmHg) and appears as two numbers: systolic pressure (the first number) over diastolic pressure. A normal blood pressure reading is within this range of 120 - 90 / 80 - 60.[50] Deeply rooted in our collective consciousness is the link between salt consumption and elevated blood pressure, leading to frightening diseases.
Hypertension is a primary component of cardiovascular disease and, as such, is the leading cause of preventable deaths.[51] ‘Preventable’ because drug and lifestyle interventions are available to lower blood pressure. Between 1990 - 2019 global rates of hypertension have doubled.[52] However, in the UK, hypertension has dropped steadily since 1975, making it the least affected country in Europe and 195th out of 200 countries assessed in 2015.[53] Using the same ranking data, the countries with the highest prevalence of hypertension, starting with the leader and descending, are Croatia, Latvia, Lithuania, Hungary, Slovenia, Romania, Poland, Czech Republic, Montenegro and Slovakia. That makes Eastern Europe the global hub of hypertension. Have a look at the chart below:
Notice that 6/10 of the countries (in red on the chart) that consume the most salt are also in the Top 10 Hypertension column. These rankings aren’t proof of anything because the studies used to gather these data simply can’t show a single dietary factor as causative, not even close, but this aligns nicely with the belief that salt drives hypertension. A quick look at the smoking rates in each of the Top 10 Hypertension countries is revealing…[57] The Chinese consume the most salt per day and are 181st out of 200 on the hypertension chart. There must be more to the story.
Niels Graudal MD, a salt research scientist, quoted at the beginning of this Salt section, reminds us how odd it is to label an essential mineral as toxic. But it’s vital to remember that anything becomes toxic beyond a certain level. When did it all start?
When did we all become so scared of salt?
You may not know, but a war has raged for 120 years.
In 1904, the Salt Wars started after two French scientists theorised that salt raises blood pressure. Ambard and Beauchard showed an association between salt consumption and raised blood pressure in six patients.[58] A few years later, a German scientist contradicted those results with his own.[59] Over the next few decades, two armies of scientists faced off, each side slinging research of various quality. The sceptics, unwilling to be wooed by the simplicity of the idea and demanding more proof that the body is incapable of balancing its blood salt levels, against the supporters, those who believed the theory to be sound science because of the observational data and because it made sense to them.
Just before the debacle of the US Dietary Goals (1977), two scientists, George R. Meneely and Harold D. Battarbee from the Louisiana State University Medical Center, published a paper entitled ‘High sodium-low potassium environment and hypertension’.[60] They were supporters of the salt raises blood pressure hypothesis but had added some complexity, saying the real issue was a combination of high salt, specific genetics and low potassium levels. At the time, nutrition was a hot topic, and newspapers and magazines often featured the world’s first governmental dietary guidelines on the front pages. Meneely and Battarbee’s nuanced approach didn’t translate well into headlines, so the media ran with something akin to Salt Causes Hypertension! Even that could have been forgiven, but governmental advice did precisely the same. That year, the dietary advice from the US government, which echoed across the world, was that all Americans should restrict their salt intake to 3 grams of salt (1.2 grams of sodium) per day.[61] Accepting that this number was too low, the committee revised it to 5 grams of salt per day, which is about 2 grams of sodium.[62] After seeing the government’s advice to reduce dietary salt, the American Medical Association (AMA) publicly stated, ‘[the committee] fail to support the hypothesis that salt consumption is a major factor in causing hypertension’. However, the US Dietary Goals, which became the US Dietary Guidelines (1980), had too much inertia.
In 1991, researchers published the first review of low salt trials. Sixty-eight trials, 10 of which were randomised, found that by reducing salt by about 3 grams per day, individuals aged 50-59 could decrease their blood pressure by an average of 5/3 mm Hg (systolic/diastolic) or by 7 mm Hg in those with hypertension.[63] The authors decided that if everyone could reduce their salt consumption by 3 grams per day, they could reduce stroke incidence by 22% and ischemic heart disease by 16%. And, by reducing it further, 75,000 lives per year in Britain could be saved. Impressive projections. However, in true Salt Wars style, more published research cast doubt on those data.
Gradual and two other researchers included only data from randomised trials to raise the standard of the research used for their systematic review and meta-analysis.[64] The 58 RCTs assessed could not match the results from the 1991 review mentioned above. In patients with hypertension, a low-sodium diet reduced their blood pressure by just 4/2 mmHg (systolic/diastolic). They observed a systolic change nearer to 1 mmHg in people without hypertension, with no significant change in diastolic mmHg.
Newspaper headlines tell us of the toing and froing conflict over the past decade:
What is the body’s response to salt?
When we need salt, we crave something salty.[65]
Generally, when we’ve had something salty, we drink more fluids.[66] In fact, if you think bar staff are being charitable by leaving salted peanuts out for you, think again. A handful of this salty snack engages an ancient system over which you have little control. Thirst. You become thirstier than you would have been without the salty snack. The bar has just swapped a few pennies worth of salted peanuts for a few pounds of thirst-quenching lager.
However, it seems that thirst might only be the short-term response to a salty snack. In 2017, researchers from the German Aerospace Center and Max Delbrück Center for Molecular Medicine made a surprising discovery about salt.[67] For 105 and 205 days, scientists locked up ten healthy volunteers inside a series of interconnected space modules. The peering scientists were in complete control of the volunteer’s diets and in the unique position of being able and willing to collect all of their bodily waste. They used salt between 6 and 12 grams daily while maintaining the inmate’s fluid intake. They were shocked by what happened. At 12 grams of salt per day, the volunteers’ kidneys dumped more salt into their urine but held onto more water by adjusting hormone levels responsible for mineral and water balance. Urea—still believed to be nothing more than a waste product formed in the liver after breaking down proteins—facilitated the separation of sodium from water. Surprising the researchers, the volunteers complained of hunger, not thirst. Their blood pressure remained constant. The volunteers were not salt-sensitive and, as such, remained in homeostasis.
Sodium and water are constantly balancing each other in a process called osmoregulation. As blood sodium levels rise, signals shoot off to the brain, triggering the release of hormones. These hormones instruct the kidneys to retain or release sodium and water to maintain balance. On average, our kidneys may filter between about 1.45 kg and 1.63 kg of salt or 0.58 kg and 0.65 kg of sodium per day, approximately 150 times more than the amount of salt we typically consume daily.[68] That means a healthy person can filter the recommended daily limit of 6 grams of salt in five minutes. But what if you’re not entirely healthy?
Is salt sensitivity the real issue?
About 26% of people with normal blood pressure are salt-sensitive.
So, 74% of people do not experience a rise in blood pressure after eating salt. [69]
Researchers characterise salt sensitivity by changes in blood pressure that mirror dietary salt intake.[70] There is also a phenomenon called inverse salt sensitivity, which sees the blood pressure drop after consuming salt. In 2023, a team of researchers published their findings in the Journal of Hypertension. According to them, 21.4% of normotensive people (people with normal blood pressure) experience a drop in their blood pressure after eating salt.[71] Salt sensitivity and inverse salt sensitivity are both associated with an increased risk of hypertension.[72] The definition for inverse salt sensitivity has yet to emerge fully formed, with another meaning being an increase in blood pressure despite being on a low salt diet.[73] This lack of definition reminds us that the human body is still mostly a mystery to our scientists and explains the confusion about salt's precise role in all of this. According to a 2001 study published in Hypertension, 73.4% of the 123 subjects who died from cardiovascular events in a group of 596 were salt-sensitive.[74] Salt sensitivity affects about 50% of people with hypertension.[75] So, what causes salt sensitivity?
Potassium deficiency and salt sensitivity
90% of British people don’t eat enough potassium.[76]
This is because they’ve replaced whole foods, which are good sources of potassium, with ultra-processed foods, aka junk foods. Fifty-six per cent of a standard British diet is junk foods.[77] Junk foods are high in calories and low in nutrients, including potassium. Frustratingly, there’s also been a 38% drop in nutrients in our fruits and vegetables as we destroy our soils with farming chemicals.[78] Potassium deficiency impairs the kidneys' ability to excrete sodium, leading to increased blood volume and pressure.[79] In other words, a potassium deficiency can cause salt sensitivity.[80] When doctors address the potassium deficiency, and in the absence of different causes, the salt sensitivity reverses.[81]
Insulin resistance and salt sensitivity
Half of those people with salt sensitivity also have insulin resistance.[82] Insulin resistance is a condition where the body's cells don't respond appropriately to insulin, leading to higher blood sugar levels and possibly diabetes type 2. Compared to salt-resistant people (people whose blood pressure does not respond to salt in either direction), salt-sensitive people have severe insulin resistance.[83] Excessive sugar consumption, particularly fructose, can cause insulin resistance.[84] In an interview with the University of Colorado's medical research blog, CUConnections, Richard Johnson, MD, author of ‘The Fat Switch,’ discusses a potential mechanism with the interviewer. Fructose causes high levels of uric acid, which damages the kidneys, leading to sodium retention and high blood pressure, Johnson explains.[85]
The obesity and genetic link to salt sensitivity
Scientists have identified multiple genes that increase the likelihood of salt sensitivity.[86] Unsurprisingly, there is a lot of crossover between these genes and hypertension.[87] Remember that genes do not predict your future, but they make it more important to take preventative action against certain conditions, such as salt sensitivity and hypertension. Remaining slim is probably one of the most powerful things someone can do to protect themselves from ‘bad genes’[88] given the tungsten strong links between obesity and insulin resistance and hypertension.[89] Shrinking obesity reduces salt sensitivity and hypertension even if someone has a genetic predisposition to either.[90]
What’s the salt sweet spot?
Scientists refer to a 'sweet spot' as a U-shaped or J-shaped curve, which describes the pattern formed by plotted data on a chart; see the image below. Simply put, too much salt and too little salt increase someone’s risk of dysfunction and disease.[91] A team of 26 cardiovascular scientists evaluated four studies with a total of 133,000 people in different countries.[92] The results, published in one of the world’s most prestigious scientific journals, the Lancet, showed a protective effect of 4 - 5 grams of sodium (10 grams and 13 grams of salt) compared to less than 3 grams daily (8 grams). British people consume about 8 grams daily. The average guideline recommends no more than 6 grams.
In 2011, some of the same researchers found a J-shaped curve for sodium consumption. Published in a top medical journal called The Journal of the American Medical Association (JAMA), they found the most protective range was between 4 and 6 grams of sodium (~10 - 15 grams of salt). Higher than that or below 3 grams of sodium (~8 grams of salt) per day was associated with a greater risk of stroke, heart attack and death.[94]
Three years later, some of the same researchers collected urine samples from 101,945 people in 17 countries to estimate sodium and potassium intake.[95] These estimates are much more accurate than the epidemiological data used to assess salt consumption. The authors, published in the New England Journal of Medicine, America’s foremost medical journal, found a sweet spot in sodium consumption. Cardiovascular risks increased from 6 grams of sodium per day (~15 grams of salt) escalating above 7 grams (~18 grams of salt), particularly in those with hypertension. The risks also rose when sodium intake dropped below 3 grams daily (~8 grams of salt). The more potassium people ate, the lower their risk, aligning with the fact that potassium reduces salt sensitivity and helps with sodium excretion.
In a pooled analysis of 133,118 individuals from 49 countries, researchers explored how sodium intake affects cardiovascular events and mortality differently in individuals with and without hypertension.[96] The study, published in the Lancet, found that higher sodium intake increased systolic blood pressure more in people with hypertension than in those without. Among hypertensive individuals, both above 7 grams of sodium per day (~18 grams of salt) and below 3 grams per day (~8 grams of salt) were linked to increased risks of cardiovascular events and death compared to between 4 and 5 grams of sodium per day; 10 and 13 grams of salt respectively. In contrast, high sodium intake did not increase the risk for those without hypertension, but low sodium intake did.
A 2021 study entitled ‘Sodium Intake and Health: What Should We Recommend Based on the Current Evidence?’ is a recent review by the authors from several of the studies we’ve cited in this section.[97] They write in their abstract, ‘We contend that current evidence indicates that most people around the world consume a moderate range of dietary sodium (3 to 5 g/day), that this level of intake is associated with the lowest risk of cardiovascular disease and mortality, and that the risk of adverse health outcomes increases when sodium intakes exceed 5 g/day or is below 3 g/day.’ (Emphasis added). Notice that it’s sodium again, not salt. That’s more than 13 grams of salt daily at the high end and 8 grams at the low end. A year later, a different team of researchers came up with very similar safe amounts: between 3 and 6 grams of sodium daily.[98]
Who might want to increase their salt intake?
Telling the whole world to decrease the amount of salt they consume without knowing exactly how much people eat, or indeed how much people lose, is as crass as telling people to eat more with the same gaping hole in information. Remember that in the UK, 61% of our salt intake comes from processed and packaged food, and by eliminating that, the average Joe/Jo would drop their totals to 3 grams of salt per day plus the replacement as discussed above in How much salt are we eating nowadays? Three grams of salt equals about 1.2 grams of sodium daily, a touch over double the 0.5 gram minimum to keep people alive. If the sweet spots established by the researchers above are accurate, 1.2 grams is way too low. Some people need more salt and other balanced electrolyte minerals to remain healthy or restore health.
Heavy sweaters need more salt
Have you ever exercised so hard that salt crystals form all over your t-shirt when it dries? That salt and water need restoring, preferably before it makes pretty patterns on your t-shirt. This is partly why electrolyte products exist.
Current recommendations do not take into account sodium lost in sweat, which can be as high as between 3.5 grams to 7 grams during an event in hot weather, according to some sports scientists. [105] They recommend vigorous exercises to restore between 10 and 15 grams (1.7-2.6 teaspoons) of salt daily.
A 2023 study on rehydrating after exercise recommends consuming between just under 1 gram to nearly 2.5 grams of sodium post-exercise for optimal rehydration and recovery.[106]
Low-carb & keto dieters may need more salt
People on low-carb diets, especially ketogenic diets, have lower insulin levels. Insulin helps the kidneys retain sodium. When insulin levels drop significantly, the kidneys excrete more sodium and water to maintain the acid-base balance. This extra excretion increases the need to replenish lost sodium to maintain electrolyte balance. Maintaining balance is particularly relevant in the first few weeks of going ‘keto’ as imbalance presents as the dreaded keto flu. People can address keto flu by restoring their electrolytes.[107]
People who don’t eat processed foods may need more salt
If you’re making most of your food from scratch, congratulations. You are in a unique minority of health-conscious people. You have complete control over the amount of salt you add to your food, and depending on your lifestyle and health, you can easily adjust to your wants and needs. However, due to an oversimplified public health message,
Some health-conscious people may have lowered their salt intake too low in a misguided bid to remain healthy.
If you’re unsure, ask your doctor for a blood sodium level test.
Do coffee drinkers need more salt?
Coffee has a mild diuretic effect, meaning it makes people urinate more often.[108] Depending on how much coffee someone drinks and their response to it, some electrolytes, especially salt, may be worthwhile. But, this is very dependent on the other aspects of their diet and lifestyle, some of which we discuss in this section. Caffeine may help reduce salt-sensitive hypertension by activating a kidney channel that helps balance sodium levels.[109]
Chronically ill people may need more salt
Addison's disease is a disorder where the adrenal glands fail to produce enough hormones, including cortisol and aldosterone. Aldosterone regulates sodium and water balance in the kidneys. When it becomes deficient, more sodium is needed to restore balance.[110] Postural Orthostatic Tachycardia Syndrome (POTS) is a condition that affects blood pressure and heart rate. High-sodium diets have been shown to improve symptoms.[111]
Stressed people may need more salt
The perception of stress triggers physiological responses, including increased blood pressure. This is partly about sodium retention. After the stress is over, the body must restore balance by expelling sodium in urine. When people are chronically stressed, this restoration takes place at night.[112] Depending on that individual’s diet and lifestyle, it may be important to replace the lost sodium to help restore homeostasis. Of course, it’s critical to address the cause of the stress as well .
If it’s not salt, what is it?
Let’s be clear: for some salt-sensitive people, salt is the trigger of their hypertension. We resisted using the word cause instead of trigger there because salt sensitivity hypertension is caused by those things we listed above in Is salt sensitivity the real issue? Potassium deficiency, insulin resistance, specific genes, being obese, kidney disease, and other things that are yet to be determined, no doubt.[113] Remember, the vast majority of people with normal blood pressure are not salt-sensitive. In the 2021 review paper quoted in ‘What’s the sweet spot?’, the authors provide evidence that salt consumption assessments are close enough despite methodological flaws. The most striking thing they write is that 8 - 13 grams of salt per day, according to these experts, actually offers a cardio-protective effect.[114] If they’re correct, then only the Chinese and Hungarians are at risk of overdoing salt in the absence of salt sensitivity, of course. If salt within these ranges is not causing salt sensitivity, then what is? DiNicolantonio, author of The Salt Fix, makes the case that sugar, particularly fructose, is causing obesity, kidney dysfunction and insulin resistance that is in large part driving salt sensitivity.[115] We briefly discuss this in the section, Insulin resistance and salt sensitivity.
The real reason your electrolyte minerals are out of whack.
The single best way to keep your electrolyte minerals in balance is to stop eating ultra-processed foods. Junk foods are a massive factor in salt sensitivity. Cast your mind back to near the beginning of this article, when we said taking one or two minerals can upset the balance of the others. Eating high amounts of salt without ample potassium can cause salt sensitivity and hypertension. When people reduce the amount of junk foods they eat, they typically replace them with whole foods, which are much more nutritious and contain potassium and other electrolytes that play well together. Whole foods are also more satisfying and typically lower in calories.
Junk foods are highly correlated with obesity because they’re so high in calories and so low in nutrients. They’re also addictive and too easy to overeat. Remember that obesity also causes salt sensitivity and a host of other conditions. Junk foods are high in sugars, including fructose. In fact, many junk food snacks that pretend to be healthy contain fructose because, being fruit sugar, some perceive them as healthier. They say a little bit of knowledge is a dangerous thing. Excessive fructose consumption induces salt sensitivity, at least in rodents.[116] Don’t be a human experiment.
Interestingly enough, Eastern Europe, the hub of hypertension, has junk foods that are higher in fructose than the UK and Central Europe.[117] Of course, correlation doesn’t prove causation. Nowadays, only the sugar industry scientists continue to blame anything but sugar. Studies have repeatedly shown that fructose causes not only obesity but also insulin resistance.[118]
As you know, insulin resistance can cause salt sensitivity by hindering the kidney’s sodium excretion. The metabolic condition also increases the reabsorption of sodium by the kidneys.[119] A healthy body can excrete sodium easily and quickly when needed, but when it can’t, the blood pressure rises. About 12% of people in the UK are insulin resistant; that’s over five million people.[120] In the United States, researchers have estimated that number at 40%.[121]
It doesn’t have to be complicated
Electrolytes are critical to the normal functioning of your body. If you think your diet is deficient in them, we urge you to start swapping junk foods for healthier, more nutritious options. Taking the time to cook from scratch pays dividends in health and longevity—what’s better than that?
Salt sensitivity is a symptom of deficiency, dysfunction and disease. It’s also the defining issue when discussing the dangers of salt. You can reverse the condition or reduce your chances of becoming salt-sensitive in the first place by improving your diet and lifestyle. Choosing whole foods will provide your body with the electrolytes needed to maintain homeostasis. A balanced and targeted electrolyte supplement before and after vigorous or endurance exercise can make all the difference to your performance, rehydration and recovery by restoring those minerals lost in sweat. And, for those people covered in the section, 'Who might want to increase their salt intake?' using a sugar-free electrolyte drink first thing in the morning may be the missing piece in the health and boundless energy puzzle.
Disclaimer: This article contains general information challenging the existing UK guidelines on salt consumption and is for educational purposes only. It is not intended to replace personalised medical advice. Always consult with your doctor before starting any new diet or supplement regimen.
About the author
Tim Rees, BSc mBANT rCNHC, is a registered clinical nutritionist specialising in dietary and lifestyle interventions for chronic diseases. Combining his dual passions of nutrition and history, Tim crafts engaging narratives that breathe life into subjects that might otherwise be considered dry. Operating from his home base in scenic Bavaria, Tim immerses himself in the natural beauty of the surrounding mountains and lakes whenever possible.
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