Sodium

Sodium is the main positive ion outside the cells, just as potassium is the main one inside them. It determines the volume of extracellular fluid, enables nerve conduction and muscle contraction, and drives transporters that bring glucose and amino acids into cells.

It is absolutely essential. The problem is the amount.

Within that, two practical points change the whole picture:

1. About 70-75% of the sodium in the Western diet doesn’t come from the salt shaker. It is already in bread, cheese, processed meat, sauces, canned goods and restaurant food. What this means: cutting salt in your cooking is a quarter of the problem.
2. Sea salt, Himalayan salt and table salt contain almost the same amount of sodium by weight. The difference is in crystal size, color and price — not in health.

Dosage and sources

A conversion worth knowing: salt is sodium chloride. 1 g of salt = 400 mg of sodium. A teaspoon of salt (about 6 g) = 2,400 mg of sodium — more than the entire daily allowance.

Benefits (Pros)

1. Fluid volume and normal blood pressure

Sodium determines how much water stays in the extracellular space. Without it, blood volume and normal blood pressure cannot be maintained — which is why a sharp drop in sodium is no less dangerous than an excess.

2. Nerve conduction and muscle contraction

The sodium-potassium pump (Na⁺/K⁺-ATPase) creates the resting potential of every excitable cell. The action potential itself is an inward flow of sodium — the basis of every nerve signal and every muscle contraction.

3. Absorbing nutrients

Sodium-dependent transporters (SGLT) bring glucose and amino acids into intestinal cells. This is also the basis of oral rehydration solutions (ORS) for diarrhea — the solution combines salt and sugar precisely to exploit this mechanism.

4. Physical performance in prolonged effort

Sweat contains 400-1,500 mg of sodium per liter. In activity lasting more than two hours, especially in the heat, replacing sodium matters — and heavy sweaters need it more.

5. Iodized salt

In some countries iodized table salt is a major source of iodine — although Israel has no mandatory iodization, and that is an entirely separate consideration.

Downsides and Side Effects (Cons)

1. Blood pressure — the established link

High sodium intake raises blood pressure, and reducing intake lowers it. The DASH-Sodium trial showed this clearly, and the effect is stronger in people who already have hypertension, in older adults and in certain populations. Hypertension is a leading risk factor for stroke, cardiac events and kidney disease.

2. “Salt sensitivity” — the explanation for the debate

Not everyone responds to the same degree. About a third of the population is classed as “salt-sensitive,” and in them the change in blood pressure is marked; in others it is small. Sensitivity rises with age, excess weight and kidney disease. Because there is no readily available test for sensitivity, the public recommendation applies across the board.

3. Additional risks beyond blood pressure

• Stomach cancer — high salt intake, and especially pickled and smoked foods, has been consistently linked to increased risk.
• Kidney stones and calcium loss — excess sodium increases urinary calcium excretion.
• Worse fluid retention in heart failure and cirrhosis.

4. Sea salt and Himalayan salt — the myth

This is one of the most common misconceptions in the food aisle. Sea salt, Himalayan salt and table salt are all 97-99% sodium chloride. The “extra” minerals in Himalayan salt are present in tiny amounts with no nutritional significance.

The only nuance that does exist: coarse salt with large crystals takes up more volume, so a teaspoon of coarse salt contains less sodium than a teaspoon of fine salt — but by equal weight, the amount is the same. See the comparison of table, sea and Himalayan salt.

5. Hyponatremia — the opposite direction

Sodium that is too low is dangerous, and sometimes fatal. Symptoms: confusion, headaches, nausea, seizures and brain swelling.

The main causes:

• Drinking too much water during prolonged exertion — “exercise-associated hyponatremia,” a known phenomenon in marathons and triathlons. Runners affected by it drank too much water, not too little.
• Diuretic drugs, especially thiazides.
• SIADH, heart failure, cirrhosis and kidney disease.

6. Salt substitutes — not for everyone

Salt substitutes based on potassium chloride reduced stroke and mortality in a large trial. But they are dangerous for kidney patients and for people taking ACE inhibitors, angiotensin blockers or potassium-sparing diuretics.

Summary

Sodium is essential, and most people consume twice the recommended amount. The most effective tool for cutting back is not the salt shaker — 70-75% of sodium is already in bread, cheese, processed meat, sauces and restaurant food. Cutting processed food does more than any change in cooking. Two myths worth letting go of: sea salt and Himalayan salt are not “healthier” — they are 97-99% sodium chloride, just like table salt; and less sodium is not always better — hyponatremia from exertion and excessive water drinking is a real danger. And finally: increasing potassium works alongside cutting sodium, and sometimes even better.