Many bloggers known for their contrarian arguments on everything related to nutrition, which they brandish without a shred of evidence, are now claiming that eating a low-salt diet is unhealthy and leads to “increased mortality.”
They also claim that it’s not the quantity of salt that matters, but the quality. For this reason, they recommend particular types of salt like Himalayan salt.
The arguments used to redeem salt are even weaker than those used to endorse saturated fats. But unfortunately, too many people have fallen for them and will die an early death as a result.
What’s even stranger is when those bloggers are otherwise recommending a sort of Paleo Diet or “return to unadulterated foods.” When they claim that “no tribe has ever lived on a vegan diet,” are they aware that those very tribes, which they use as dietary models, didn’t consume salt — a recent addition to humanity’s diet?
Why Salt is a Poison
Dr. Lewis Dahl was one of the first scientists who researched the effects of salt on blood pressure. When he found that a low salt intake lowers blood pressure, his natural question was “does a high salt intake cause increased blood pressure?”
In the 60s, he bred two strains of rats with different sensitivity to salt in developing hypertension. His experiments started building the case against salt.
Opponents will claim that this was insufficient to prove that salt is a major cause of hypertension in humans, and have often trashed Dr. Dahl’s work on that basis. However, they have failed to examine the rest of the evidence against salt. And since 1954, the science has added up.
Here are the arguments against salt, none of which have ever been considered by salt apologists:
1) Human beings are adapted to a very low sodium diet, through millions of years of evolution (from pre-human species to modern humans). We ate natural foods that were low in sodium. Breast milk is low in sodium. (Cow’s milk contains much more sodium, by comparison). Because of this, we are genetically programmed to function on a low-sodium diet and eliminate excess sodium in the urine.
2) When Europeans discovered isolated tribes and communities that did not use salt, they found that they also never experienced hypertension in their lifetime. On the other hand, modern humans on modern diets have a 60-80% chance of developing hypertension in their lifetime.
3) There were exceptions to this rule, and a few isolated tribes and communities used salt. For example, scientists studied the Lau tribe in the Solomon Islands between 1966 and 1970. They had the highest blood pressure readings in the region, and also happened to cook all of their fish, sweet potatoes and greens in seawater – so they had a high salt intake.
4) Scientists discovered that the sodium requirement for humans is only 300-500 mg a day. Most people consume over 4000 mg. a day, sometimes up to 6000 or 8000 mg.
5) Chimpanzees are 98% genetically similar to human beings. That noted, scientists tested the salt theory on a group of chimpanzees. Salt intake was progressively increased to 5800 mg a day. Their blood pressure rose by 33/10 mmHg. Even on just 1900 mg. of sodium a day, their systolic blood pressure increased 12 mm. When the scientists removed salt from their diet, their blood pressure slowly came down to their pre-experiment levels.
6) Human experiments showed the same thing.
7) The Rice-Fruit Diet by Dr. William Kemptner was one of the first diets ever used to treat hypertension before drugs were available. It contained 150 mg. of sodium per day. This diet was extremely efficient in treating the most severe case of hypertension — in most but not all people. Later studies found that it was the low-sodium content that gave the results. Blood pressure went up with added salt, but not with added protein. They were able to add 500 mg. of sodium a day without an increase in blood pressure, but not more than that. *10
8) We know that Thiazide medicines lower blood pressure, probably by increasing sodium excretion.
What’s Normal Blood Pressure?
Normal blood pressure is not 120/80. That is simply the cutoff at which your doctor will start worrying about high blood pressure. They’ll probably not worry until you hit 140/90, the point at which the benefits of hypertension medications begin to outweigh the risks.
Normal blood pressure is UNDER 110/70. Few people in Western societies achieve such blood pressure over a lifetime because of our diet and high-salt intake.
How Salt Increases Blood Pressure
Humans evolved on a low-sodium diet. Our requirements are very low, under 600 mg — a day. When we start introducing more and more sodium to our diet, our body must work harder to get rid of this extra sodium.
The blood becomes saltier, and the body must dilute this salt. That means more water and more pressure.
Get too much sodium, and your kidneys will work overtime to do their job.
To suck out all of this sodium and remove it in the urine, kidneys become the best reverse osmosis machine in the world. They’ll draw extra water from your blood. But when there’s extra pressure, it puts a strain on them. High-sodium diets damage the kidneys over time.
Because of all of this extra pressure, the walls of our arteries become thicker. Eventually, small arteries can become so narrow that they clog up completely, or burst entirely because of the pressure. There goes a stroke.
The Salt Skeptics
It would take too long to go through all of the arguments of salt skeptics. But we can point out a few things:
Some studies have shown that people consuming less salt are living shorter. Explanation: This is due to a problem called “reverse causation.” In Western societies, the only people that tend to cut out sodium are those suffering from major illnesses. Therefore, it is normal to find an association between illness and low-salt intake.
In a few cases, a low-sodium diet can be deadly for people with acute heart failure, taking drugs that flush out their sodium reserves. Explanation: Those are rare cases and can’t extend to the rest of the population.
Many have raised doubts about the famous “Intersalt study,” which initially did not find a significant link between blood pressure and sodium. Explanation: The results were revised in 1996 after the authors had realized they had not corrected the numbers for a “regression dilution problem.” Salt intake was then found to correlate with blood pressure strongly. Many of those studies are flawed and paid for by the salt industry. Dr. Greger has a series of videos on this salt controversy.
Heavily controlled and rigorous human trials have shown that moderately lowering sodium to 1600 mg. a day significantly reduces blood pressure.
Because some people don’t react to sodium restriction, the average drop can appear small. But remember that every 1 point drop in systolic blood pressure leads to a 1% reduction in overall death.
Remember: the salt and processed food industries need salt to stay alive. They will put out research to try to confuse the public about salt. Meanwhile, the scientific consensus is clear: too much salt is deadly.
How to Tell If Food Has Too much Salt?
If it comes from a restaurant, it has too much salt. If your friend prepared it, it has too much salt. If it’s packaged, it has too much salt. There’s no need to even count mg. of sodium. Eat unprocessed foods that you prepare yourself. If you eat any amount of restaurant food, you’re consuming too much salt.
What About Gourmet Salts?
I can’t end this article without answering a question that will inevitably come up. What about Himalayan salt? Celtic salt? Braggs Liquid Aminos?
The truth is that it doesn’t matter. Yes, some of these salts contain an array of minerals. But most of what’s in it is sodium chloride.
It’s not about salt per se — it’s about sodium. Too much sodium is the problem. And all of those products and more contain a lot of sodium. Because many gourmet salts are moist, one teaspoon of it might contain less sodium. But it still contains mostly sodium — which is a lot.
Braggs, which isn’t as popular nowadays, contains just as much sodium as soy sauce. It looks like it holds less on the label because they play with the serving size.
Even if you used dried celery juice as a powder, you could still get too much sodium if you ate enough of it. The source doesn’t matter. The quantity does.
The Killer Argument Against Salt
Some people may say, “I eat a lot of salt and my blood pressure is fine!”
In reality, salt raises blood pressure in almost EVERY individual, although it may take a lifetime for the problem to become apparent. Only 30% of the population does not have hypertension by age 65. And out of those people, 90% will develop it by the end of their lives. If those individuals lived even longer, they would also get hypertension.
In societies where salt is unknown, the percentage of the population that develops hypertension with age is zero, even when they smoke, drink alcohol or eat meat.
In other words, it’s just a question of time before salt causes hypertension. If you’re lucky, it will just take more time.
However, salt intake affects you in other ways!
Even if you don’t have high blood pressure, salt damages your body in other ways. Salt intake causes kidney damage, stomach cancer, kidney stones, and has recently been linked to autoimmune diseases. But this is only the beginning.
“High sodium intake results in massive albumin excretion, oxidative stress, severe renal arteriolar damage, interstitial fibrosis, increased glomerular hydrostatic pressure, glomerular hyalinization, fibrosis, and end-stage renal disease independently of increased BP.”
The Pledge to Eliminate Salt
All my life I tried to reduce salt, and I concluded that it’s not possible to restrict such an addictive substance. The only method that works is to eliminate it 100%.
We don’t need more sodium than what’s in natural foods! US guidelines for RDA (Required Daily Amounts) states that “the minimum average requirement for adults … [is]… 115 mg of Sodium…per day. In consideration of the wide variation of patterns of physical activity and climate exposure, a safe minimum intake might be set at 500 mg/day.”
Human beings evolved on a low-sodium diet. Therefore our kidneys are adapted to conserve sodium. Salt is NOT paleo! Most humans never had any access to salt up to relatively recently in history.
99.4% of the population consumes more than the 1500 mg. limit of sodium set by the American Heart Association. But the actual ideal intake for optimal health is less than 1000 mg, probably around 500 mg. So the argument that “many people run into health problems by not consuming enough salt” does not hold water!
Remember that optimal blood pressure is under 115/75. Any improvement you can make in your blood pressure numbers will vastly improve your health outcomes!
Even if you consume salt and have an optimal blood pressure of under 115/75, it does not mean that you should keep using salt. 95-99% of people develop essential hypertension if they eat salt, as long as they live long enough. Some people develop it at 35, while others at 85.
One problem with a lot of the research done on sodium restriction is that they focus only on the short-term effect of going from a high-salt intake to moderate salt intake.
According to Dr. James Kenney, Ph. D., author of a fascinating paper or salt toxicity:
Unfortunately, the long-term effects of a low-salt diet have received little attention. After an initial drop in BP, which can be quite noticeable in some individuals, the decline in BP often continues for many months or years, provided the salt restriction is maintained. For example, one group of researchers found that BP was still trending downwards after two years on a diet with about 70 mEq (1600 mg of sodium). Given that the BP raising effects of excessive dietary salt take many years to develop it is surprising that most clinicians expect to see the full impact of a low-salt diet within just a few weeks. In my clinical experience, it may take as long as 5 to 7 years to see the full BP lowering impact of a low-salt diet.
I hope I have convinced some of you to try ditching the salt habit!
REFERENCE 2: Blood pressure in four remote populations in the INTERSALT Study. http://www.ncbi.nlm.nih.gov/pubmed/2767757
REFERENCE 3: Antecedents of Cardiovascular Disease in Six Solomon Islands Societies http://circ.ahajournals.org/content/49/6/1132.short
REFERENCE 4: The effect of increased salt intake on blood pressure of chimpanzees. http://www.ncbi.nlm.nih.gov/pubmed/7489355
REFERENCE 5-Moderate sodium restriction and diuretics in the treatment of hypertension. http://www.ncbi.nlm.nih.gov/pubmed/4564947
Reference 6: Hypertension treated by sodium restriction.
Reference 7: Double-blind randomised crossover trial of moderate sodium restriction in essential hypertension. http://www.ncbi.nlm.nih.gov/pubmed/6120346
Reference 8: Double-blind study of three sodium intakes and long-term effects of sodium restriction in essential hypertension. http://www.ncbi.nlm.nih.gov/pubmed/2573761
Reference 9: An overview of randomized trials of sodium reduction and blood pressure. http://www.ncbi.nlm.nih.gov/pubmed/1987008
REFERENCE 10: DIETARY TREATMENT OF HYPERTENSION. CLINICAL AND METABOLIC STUDIES OF PATIENTS ON THE RICE-FRUIT DIET. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC436162/pdf/jcinvest00410-0077.pdf
Reference 11: TREATMENT OF HYPERTENSION WITH CHLOROTHIAZIDE, http://jama.jamanetwork.com/article.aspx?articleid=325216
REFERENCE 12: Intersalt revisited: further analyses of 24 hour sodium excretion and blood pressure within and across populations. Intersalt Cooperative Research Group. http://www.ncbi.nlm.nih.gov/pubmed/8634612