Is Salt Unhealthy? Can Eating More of it Give You Hypertension?
Sodium Chloride is a very important chemical compound in nature. It induces a characteristic taste in us that we describe as “salty” and we call this compound “salt”. Humans and animals crave this taste very highly and resultantly salt has been a very highly valued commodity all throughout our history and evolution, across all cultures around the world.
Throughout pre-historic times, animals would create paths to salt licks(natural deposits of salts that animals go to “lick” and derive essential minerals). Humans developed settlements around these salt licks.
Its importance is reflected in our language too. The word “salary” is derived from the Latin word “salarium” which meant the money allotted to Roman soldiers for the purchase of salt. The expression “worth their salt” is very popularly used to denote value. There are many other examples.
In modern times though(since the last 50 years to be more specific), salt has been largely demonized. Lowering salt intake has been a general health guideline and higher salt intakes have been said to cause hypertension and cardiac issues. This might appear to be just another case of us going overboard with yet another thing in this age of abundance. But as it turns out, the actual story is a little more complicated for this one. Because the idea that a higher salt intake is bad for your health is another big myth created by modern medicine. One that has been going around for decades despite very strong evidence to the contrary, especially in the last 10-20 years. But, as we’ve mentioned earlier, paradigm shifts are always difficult in medical science and this one is a big example of that.
Why is Salt Deemed a Health Hazard?
Let’s proceed to look into the problems cited with a higher salt intake and the evidence around them. The primary issue with a higher salt intake is said to be hypertension, which in turn causes cardiac issues, kidney issues, and brain stroke among others.
Hypertension is defined as a health condition where the pressure exerted by your blood on the walls of your arteries and vessels is chronically high.
This is definitely a problem and it can indeed lead to the aforementioned issues. Hypertension does not usually cause symptoms, at low to moderate levels. At higher levels, it may cause symptoms like headaches, dizziness, flushing, nosebleeds, tremors, and irregular heartbeat among others.
Hypertension is a highly prevalent condition:
- An estimated 1.28 billion adults aged 30-79 years worldwide have hypertension, most (two-thirds) living in low- and middle-income countries
- An estimated 46% of adults with hypertension are unaware that they have the condition.
- Less than half of adults (42%) with hypertension are diagnosed and treated.
- Approximately 1 in 5 adults (21%) with hypertension have it under control.
- An estimated 1.28 billion adults aged 30-79 years worldwide have hypertension, most (two-thirds) living in low- and middle-income countries WHO
Salt– The Cause of Hypertension?
Salt intake is still considered the primary cause of hypertension, and hence there is a huge push to reduce salt intake in the population, and official health guidelines everywhere strongly emphasize the same. WHO Member States have signed an agreement to reduce the global population’s intake of salt by a relative 30% by 2025.
As we can see, all of this is based on the single assumption that higher salt intake is the primary cause of hypertension. This is a hypothesis that has never been proven. If we include most of the recent literature, there is actually more data to disprove this hypothesis than to support it. In reality, the case is that there are some people in whom blood pressure rises by increasing salt intake. But this is only a small percentage of the population. And even for people with this particular condition, it’s still ignorant to say that salt causes their hypertension. It’s only a trigger(we discuss salt sensitivity in more detail later).
Other Effects of Salt On Our Health
And beyond this, if we actually take our attention off this singular salt and hypertension link, and look at the effects of salt intake on our health holistically i.e. considering all factors(which obviously is what we should do when trying to determine an intake recommendation for the public), the evidence to support a higher intake is just staggering.
If we look at the correlation between mortality rate and salt intake there is nothing to support the low level of intake that is currently recommended.
The graph between sodium intake versus all health outcomes shows a J-shaped or U-shaped curve. Meaning a moderate intake is the safest. And going too high or too low could cause problems. “Moderate” here is between 4 to 5.99g of sodium, which equates to around 12g of salt. More on exact quantities later.
Epidemiological data seems to support the same. Japanese and South Koreans live the longest and have the lowest rates of heart disease. They consume 4-5g Sodium/day and are the highest salt eating population in the world.
Another report comparing salt intake to heart disease rate shows that increasing intake to a very high amount of 8g Sodium(20g) salt increased heart disease rates by 20% only whereas lowering intake to 2.3g Sodium, which is the current government recommendation, increases it by 50 per cent!
This inverse correlation between heart disease and salt intake may be explained by the following mechanism: we see that when we do reduce blood pressure by lowering salt intake in a patient, their heart rate also goes up. Thus blood pressure x heart rate remains constant even though blood pressure falls. And it is the former that determines the overall load on the heart.
Our kidneys are very intricately designed to function as an intricate system that is able to regulate the sodium content in our blood. This is why we see across different cultures and populations, how humans are able to thrive on very highly varying salt intakes. Healthy people are generally able to adapt to a wide range of salt intakes without a significant change in blood pressure.
Obviously going extreme either way is not optimal, but our kidneys are very capable of eliminating excess Sodium. A deficiency, on the other hand, is more problematic- because Sodium is an essential mineral. Meaning our bodies have no way to manufacture it on their own. In deficient states, our kidneys try to recycle sodium and this actually puts a lot of stress on them.
Low sodium diets harden our arteries thereby increasing cardiac risks. They aggravate insulin resistance(and thus metabolic disease), which in turn is what we now know to be the biggest risk factor for hypertension. So yeah, a chronic low salt intake over the long term can eventually lead to hypertension. This happens due to an adaptive mechanism- a higher insulin level enables our kidneys to retain more sodium.
So while it’s true that a low sodium diet can aggravate insulin resistance, it doesn’t change the fact the biggest drivers of insulin resistance and metabolic disease are still a poor diet high in refined sugars, refined seed oils from processed foods and unhealthy sedentary lifestyle choices. Hypertension is just one of the ways in which metabolic illness manifests itself.
“We have been blaming the wrong white crystal for this problem”
-Dr James DiNicolantonio(world-renowned pioneer in the research of salt intake and author of the bestselling book “The Salt Fix”)
Pregnant women demand more sodium and salt restriction during pregnancy has been shown to be particularly harmful,
Sodium deficiency affects your hormones to create more stress and also drive inflammation.
Doctors and practitioners who do recognise the value of a higher sodium intake have reported from their clinical practice very commonly seeing cases where patients who were put on low salt diets due to hypertension/cardiac conditions, suffered from issues like palpitation and cramps for years. Which went away by increasing their sodium intake.
The Other Part of “Salt”
We use the words “salt” and “Sodium” almost interchangeably in nutrition science, forgetting the other half of salt- Chloride. Where do you think the hydrochloric acid in our stomach comes from? We get the Chloride in HCl from salt. So low salt diets are also a contributor to the condition of low stomach acid or hypochlorhydria, which is rampant in the population today. Low stomach acid causes bacterial overgrowth in the gut and improper digestion, which obviously drives almost all health issues as you may well know.
So How Much Salt Do We Need?
The US Dietary Guidelines(which is considered a global standard) recommend a sodium intake of less than 2.3g. The American Heart Association recommends 1.5 to 2.3 g.
1g of salt contains 0.387g of Sodium
The WHO recommends a salt intake of less than 5g(equivalent to less than 1.9g of Sodium).
Globally our average intake is estimated to be around 9-12g. And 70 per cent of that is estimated to be coming from sodium in processed foods.
So what amount do we recommend?
As per the study whose graph we shared earlier, the optimal dosage came out to be 4 to 5.99g of Sodium = 10 to 15g salt. This is a fairly optimal dosage, we think. But some experts including Dr DiNicolantonio recommend even higher, up to 7g.
Our daily requirement actually varies based on certain changing factors. We lose a lot more sodium when we workout and sweat so it's recommended to increase your intake by around 2g on days you have a heavy workout or just sweat a lot.
There are some health conditions that particularly hamper salt absorption: colon issues like colon cancer, Crohn’s, colitis, and adrenal dysfunction and stress overload, apnea, hypothyroidism. These conditions require further increased salt consumption.
People on low carbohydrate diets require more salt too since our bodies lose a lot of fluid along with their glycogen on such diets. The popularly cited condition called “keto flu” where people feel sick and dizzy when quitting carbs is known to be caused by electrolyte loss, and thus salt water is a well-known remedy to this.
Lastly, we do realize it’s not a normal practice to measure your salt intake. Fortunately, you probably don’t need to. you. Our bodies have a natural appetite for sodium which helps regulate sodium intake. So definitely listen to your salt cravings
So should everyone just universally up their Sodium intake to 4 to 6g if it’s lower? No, because, as we mentioned in the beginning, while as a population a relatively higher sodium intake does appear to be beneficial, there is such a thing as salt sensitivity which is real. It affects a small fraction of the population only. A salt-sensitive person is someone whose blood pressure increases, often quite significantly, with an increase in sodium intake. That is why we would advise people with any tendency for hypertension to track their blood pressure when increasing their sodium intake. Fortunately, blood pressure can be very easily tracked at home by oneself at no extra cost.
It is estimated that among people without hypertension, only 20 per cent are salt sensitive. And even among people with hypertension, it is around 50 per cent.
The good news is that this condition is quite easily reversible in most cases. Even though mainstream medicine refuses to do it. But functional medicine and other holistic practitioners do it quite routinely. Most commonly it gets reversed by fixing the patient’s insulin resistance. In other cases, there is an issue with the kidneys which causes the salt-pressure balance maintenance to be disturbed. There could be other causes too.
Other minerals have also been shown to affect blood pressure. There is a lot of direct evidence to show a higher potassium intake reduces blood pressure. Higher magnesium intake is also said to do this although there isn’t as much direct evidence in this case(Magnesium, in general, is extremely important though and it’s something people are vastly deficient in. So higher intakes are very highly recommended).
If you’re getting a high Sodium intake without getting enough Magnesium and Calcium to balance it out, you could experience issues from it. This is why electrolyte formulations usually contain all three of these in fixed ratios.
Getting more dietary Calcium(through diet, not supplements) has been shown to reduce blood pressure as well.
What About Our Ancestors?
There has always been a raging contest in the paleo community about how “ancestrally consistent” one is(we’ll never know who won because they probably went off the grid to live in a forest somewhere). In this particular context though, there appears to be a big anomaly: According to anthropology data estimates, palaeolithic humans consumed somewhere around 0.75g of sodium only. For this reason, some people in the paleo community even recommended a low salt diet a while back. But currently, if you’re active in the keto-carnivore space, you know that the overwhelming recommendation is to eat a higher salt diet. And this makes sense because as we previously mentioned, lower carbohydrate diets demand more salt.
It’s not well understood how our palaeolithic ancestors functioned on such a low sodium intake(assuming that indeed was the case). It goes to show that we should not be too obsessed with aping(pun not intended) our palaeolithic ancestors based on sketchy anthropological data. Especially in the face of contradictory data from well-conducted modern-day trials.
Like other carnivores, paleolithic humans presumably got almost all their salt from animal foods, particularly blood. It was only later in the Neolithic era when agriculture of grains started that deliberate salt procurement activities for consumption started.
Considering all of the data on the health effects of salt intake variation, we definitely recommend a much higher intake than the current 2.3g official recommendation. Somewhere around 5-7g, subject to variation based on factors like activity level, sweating and cravings, as mentioned above.
Salt sensitive people though, need to be cautious and carefully monitor their blood pressure when increasing their intake. For extra safety, anyone increasing their salt intake may track their blood pressure when doing so, in case they might be salt sensitive.
And if you are salt sensitive, and thus struggling to increase your intake, there is nothing to worry about. Just reach out to a good functional medicine or holistic practitioner for help. Our team at iThrive is very experienced with hypertension and salt sensitivity. You are welcome to book a short consultation with one of our nutritionists.
Stop fearing the salt shaker. Do be salty.