Salt (or Sodium), Is It Really That Evil?
And you will search it out because of the marketing hype surrounding the evils of salt and how your heart will stop if you consume this white poison!
The main alleged ‘baddie’ in salt is the sodium part of sodium chloride, so low-salt could also be represented as low sodium. Obviously, the food industry has capitalized on this message and have come up with low-salt everything. It has got so bad that you can now even get ‘low-salt’ salt!!!
Figure 1. A ‘low-salt’ salt
But then in the “healthy” aisle; I'm still not sure why they label it health food aisle if they don’t label the others as junk food aisle, and the health food is found around the outside in the form of real food and not in the packets in the aisles anyway, but I digress. In the healthy aisle, they sell all types of miracle salt to cure your ailments from fatigue to arthritis to obesity.
There are usually 3 truths to every story. The good salt story, the bad salt story and the important useful info will be somewhere in between.
Like with most health messages, there is an element of truth to limiting salt intake, but it is only a small element of truth. You see, salt is synonymous with refined and junk foods and clearly, these foods are bad for you. I promise not to insult your intelligence and bore you about how junk foods and refined foods are bad for you. Limiting refined/junk foods is a good idea of course, eliminating them forever is an even better idea. The million-dollar question is this: Is salt to blame for making junk food bad, or is it all of the other crap (sugars, carbohydrates and trans fats etc) found in junk food? This article will explore that question.
An Element of Truth
Salt – The BasicsAs mentioned, salt is a chemical also known as sodium chloride. The sodium part is the element that is associated with all the alleged health problems. The before mentioned ‘low-salt’ salt simply swaps out some of the sodium and adds back another mineral (potassium) thus you have a low-salt salt. Not exactly rocket science eh!
Yes you do. Without salt/sodium, you die. Simple as that. The word salary as a form of payment comes from the word salt and wars have been fought over salt. It is essential for life.
Do you need salt?
The argument from some asserts that there is enough salt in your food and you shouldn’t need to add it by sprinkling it on your food. Now that seems sensible however; doesn’t that depend on what you eat? I would certainly agree that you don’t need any extra salt if you are chowing down on McDonalds on most days but what if you are eating healthy, unprocessed foods? What if you are eating a smoothie and raw, unsalted nuts for breakfast, a salad for lunch and unsalted fish and steamed vegies for dinner? And what if you like doing cardio and sweating heaps? You know you lose loads of salt in your sweat. So you eat unrefined foods and sweat a lot? What if you live in tropical Queensland? You could be salt deficient! Contrast that with the ‘average’ Australian consuming processed foods and spending hours on the couch and you can see that people may have different needs.
Where in the world should I get my salt?
What about Himalayan salt?Himalayan salt is chemically similar to table salt plus mineral impurities. It consists of 95–98% sodium chloride, 2–4% polyhalite (potassium, calcium, magnesium, sulfur, oxygen, hydrogen), 0.01% fluoride, 0.01% iodine, and micro-amounts of numerous trace minerals as well as such things as iron oxide; a.k.a. rust that adds a red colour. The colour change is not associated with carotenoids from krill or algae it is from the oxidized minerals found in local rocky mountain ranges. If you are only consuming say 5g of Himalayan then the 2-5% that isn’t sodium chloride won’t contribute significantly to your overall mineral load. Having said that, the colour is really cool and does look great on the table! Also, the salt does make great lamps.
Salt to avoid – Dead Sea SaltWhile salt is salt, there is one salt that everyone should avoid. Dead Sea salt was found to be high in the toxic mineral Bromide. Simple message: avoid it or risk “Bromism”.
Can vary dramatically depending on location. Australia makes salt direct from the ocean in South and western Australia where the water is extremely clean and once washed and dried it is very white and does not need bleaching. It contains a natural blend of sodium chloride with other minerals but due to the purity it is white. Other salt suppliers in Australia can take it from lakes rich in carotenoids from algae and can supply a salt blend with extra carotenoids like astaxanthin.
Salt Deficient? Surely you Kid(ney)?That was a bad attempt at humour, but it highlights the important role the kidney’s play in regulating your blood sodium levels. (Stevo wrote that bit and he isn’t even a dad. Bad dad joke Stevo). If you consume lots of sodium, your kidneys will filter more sodium out of your urine. Conversely, if you are on a low sodium diet, your kidneys will retain sodium (this process can stress the body – more on that later). Thus, you have a little wriggle room on how much sodium you need.
The RDA for Sodium/SaltThe National Health and Medical Research Council has set an ‘Upper Limit’ for sodium intake of 2300 mg per day (corresponding to approximately 6 grams of salt). Intakes above this level are regarded as likely to cause harm. A ‘Suggested Dietary Target’ of 1600 mg of sodium (equivalent to about 4 grams of salt) has been set for Australian adults. As we look at the science later in this article, we can see how incredibly low (and dangerous) this level actually is.
In the late 1800s, salt was not demonized as a cause of water retention, oedema, and kidney disease. In fact, salt restriction was actually thought to cause some of these conditions. According to a paper published by Branche in 1885 salt depletion resulted in extreme weakness, anemia, albuminuria and edema. And as early as 1909, heat and muscle cramps from sodium depletion were well recognized symptoms. Other side effects of salt restriction included vertigo, headache, apathy, anorexia, nausea, feeble twitching of the muscles, abdominal cramps, and oliguria. More severe side effects included vascular collapse, cold extremities and large drops in blood pressure (hypotension).
The History of Salt
In 1904, two French scientists named Ambard and Beauchard further promoted the idea that salt retention was a driver of oedema and hypertension. These authors were credited for inventing the Salt-Blood Pressure Hypothesis and were one of the first scientists to spark ‘The Salt Wars’.
The Salt Wars – Through the decades
By 1930 the Journal of the American Medical Association (JAMA) encapsulated the debate during this time recommending against the use of salt substitutes due to "...our lack of knowledge whether it is the sodium or the chloride that is harmful." And that same year Strauss noted that salt restriction could lead to serious adverse consequences such as uremia. This means that low salt diets could lead to elevated uric acid in the blood, which is associated with gout.
Salt in the 1930s
In 1948, Goldring showed a lack of a significant effect on blood pressure with sodium restriction in those with hypertension and recommended against sodium restriction as a treatment for hypertension. Again, a low-sodium diet was found to cause adverse effects; this time it reduced blood flow to the kidneys, reduced filtration rate and increased the risk of renal ischemia (lack of blood flow to the kidneys).
Salt in the 1940s
Chapman and Gibbons looking at studies spanning from 1904 to 1949 found 21 "favourable" but 7 "unfavourable" studies regarding low-salt diets as a treatment for hypertension. Thus, the evidence was not clear, in some instances salt restriction worked for treating high blood pressure but other times it didn’t. Many times salt restriction caused serious adverse consequences (mentioned later) and it was extremely hard for patients to adhere to.
In one of the biggest studies on salt and heart disease (published in the Lancet medical journal), 63,559 persons with hypertension and 69,559 persons without hypertension were included. High salt consumption of ≥7 g/ day was associated with increased cardiovascular events and mortality in people with high blood pressure, whereas low salt consumption of ≤3 g/day was associated with increased cardiovascular events and mortality in people with high and normal blood pressure. In other words, salt restriction reduced cardiovascular events in only 11% of the high blood pressure population, whereas low salt consumption could be harmful in 22% of the study population, both in people with high or normal blood pressure. Remember, the Heart Foundation recommends a heart stopping 1600 mg of sodium daily, which sits it at the higher risk dose found in the above-mentioned study.
Heart Disease and Salt Intake
Regarding the relationship between blood pressure and salt each gram of urinary sodium excretion was associated with a mere 2.08-mmHg increase in systolic blood pressure (top number) and a 0.72-mmHg increase in diastolic blood pressure (bottom number) in individuals with hypertension; whereas, it was less strongly associated with increased systolic (1.22 mmHg) and diastolic (0.52 mmHg) blood pressure in individuals without blood pressure problems.
Blood pressure and Salt Intake
In contrast, studies even suggest that higher salt loads can decrease blood pressure. Luft et al suggested that, “sympathetic nervous system activity appears to decrease with sodium loading in normal subjects. These responses may have facilitated the excretion of massive salt loads in normal subjects and may have modulated the increases in blood pressure.” Low-salt diets can also lead to vasoconstriction and consuming more salt in normotensives can lead to vasodilatation.
A low salt intake, via stimulation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, may contribute to increased cardiovascular morbidity and mortality. The confirmation of this theory came via a thorough recent (2017) review by the joint working group of the World Heart Federation, the European Society of Hypertension and the European Public Health Association recently arrived at this remarkable conclusion. That means a low salt diet stresses the body out, which increases the risk for heart disease.
So why is a low salt diet dangerous?
Your body can not afford to wait to see what your stress is. In the case of low sodium and associated changes such as low body water (dehydration) or low blood volume; you stress axis is activated in case you are bleeding to death so it reacts.
A recent (2017) meta-analysis (in this case, a pooling of 185 studies on reducing sodium in the diet to the Heart Foundation level), it was found that cutting salt in your diet leads to increases in blood cholesterol and even more disturbing increases of blood fats (triglycerides). This may be yet another mechanism of how reducing salt increases heart disease.
Low Sodium – High Cholesterol?
Advice to consume < 2,300 mg of sodium/day can lead to negative sodium balance, as well as negative calcium and magnesium balance. Thus, low-salt diets may predispose to calcium and magnesium deficiency and all the negative consequences that come with it (including osteoporosis, hypertension, cardiovascular events, arrhythmias, coronary vasospasm, sudden death, and more). Furthermore, recent studies suggest that sugar not salt is the likely dietary culprit causing hypertension.
Low sodium leads to low magnesium and calcium
It was also observed that a high salt diet stimulates insulin-independent glucose uptake without interfering with insulin sensitivity, which can be due to an increase in number of glucose transporters (GLUT-1, GLUT-4, or both) in adipocytes because of a high salt diet. Hence, a high salt diet can induce protection from the harmful effects of diet high in sugar which is the likely primary dietary culprit behind obesity, atherosclerosis and subsequently hypertension.
Can salt improve insulin sensitivity?
Sure you can! You see, most people add salt to foods that are low in salt as this food is often unprocessed. If you add salt to your omelette for breakfast, salad for lunch and meat/fish/chicken and veg for dinner then go for it. Don’t overdo it! Just add it to taste.
So can I add salt to food?
Otherwise, these healthy foods may be bland and you may not want to eat them and instead, you gorge on a pizza. Remember, it is unlikely you would be adding salt to your processed McDonald’s hamburger, KFC or your pizza. These processed foods are full of salt already (and full of real baddies like refined carbohydrates, trans fats and evil preservatives).
We really are very clever if we listen to our bodies. Salt is absorbed using passive diffusion. If your body levels are low it is absorbed quickly as you need it. When absorbed quickly it spends less time on your tongue so you don’t get to taste it as much. As your salt levels rise, absorption slows and the salt lingers on your tongue longer and food tastes saltier. Follow your gut (or tongue in this instance) to know when you have enough and when you need more.
Have you ever drunk and electrolyte drink after exercise when salt depleted? It tastes sweet; and compared it to drinking when fully salt loaded it tastes salty.
The huge body of evidence suggests that the overconsumption of salt within a healthy whole foods diet is not the primary cause of hypertension, whereas salt associated with bad food with added sugars and trans fats are more likely to be the true culprit.
The bottom line
Salt restriction may actually worsen overall cardiovascular health through numerous counter-regulatory mechanisms, and may lead to other unintended consequences (insulin resistance, type 2 diabetes, and obesity).
Excessive salt intake can lead to fluid retention and if you have high blood pressure already you need to be careful not to get too much; but it is equally important to make sure you make sure you get enough of this essential nutrient.