For decades, salt has been villainized as the root cause of high blood pressure and heart disease. But when we look deeper into human physiology, the story is far more nuanced.
Salt is essential for:
- Cellular energy production (sodium drives the sodium-potassium pump that powers mitochondrial function)
- Nerve conduction and muscle contraction
- Maintaining plasma volume and circulation
Studies are beginning to show that reducing sodium intake in processed foods may be beneficial, but cutting salt intake altogether can actually contribute to an increased risk of early death. So is it the salt, or is it something else?
Why you may want to keep salt in your diet:
Sodium in the diet helps to increase active thyroid hormone, the metabolic rate, oxidative metabolism, and the production of protective carbon dioxide (CO2, which helps to lower stress hormones and inflammation. Carbon dioxide also plays a key role in water retention, (something salt is blamed for causing,) as carbon dioxide regulates the movement of calcium and sodium into and out of the cell by buffering cellular pH in the form of carbonic acid.
A severe restriction of sodium chloride intake has been associated with insulin resistance and obesity. Adequate salt intake, on the other hand, reduces stress hormone output and improves insulin sensitivity. This is particularly important in cancer prevention and healing, since stable blood sugar and a low-stress environment support optimal cellular repair.
Salt, aldosterone, & insulin resistance:
When salt intake is too low, the body compensates by activating aldosterone, a hormone that helps you retain sodium.
- Chronically elevated aldosterone can:
- Increase inflammation
- Promote fibrosis in the heart and kidneys
- Worsen insulin resistance
Several studies have shown that low-salt diets paradoxically raise insulin levels and impair glucose metabolism. In fact, restricted sodium can trigger the same stress pathways (such as cortisol and adrenaline) that drive metabolic dysfunction.
Myths vs. facts:
- Salt causes water retention. The truth is that water retention depends on the body maintaining its blood volume, which is impacted by more factors than just water and salt intake. Carbon dioxide, serum albumin, hormones, and minerals all play a role. Without enough salt, the body can actually retain more water.
- Salt restriction lowers blood pressure. While salt restriction may lower blood pressure by a few points, this doesn’t necessarily equate to improved health. Low salt intake can actually contribute to high blood pressure, as it can increase renin levels. The more important factor to consider is potassium, magnesium, and other mineral levels. The ideal salt intake is about 4-6g a day.
Not all salt is equal:
Most people’s salt intake comes from processed foods: fast food, and packaged snacks. That salt is usually low quality and paired with inflammatory ingredients.
But people avoiding processed foods, cooking at home, and eating whole foods, often swing in the opposite direction: they may actually be under-consuming salt. When you strip away processed food, you also strip away most of the sodium. If you don’t replace it with quality salt, you can feel the effects: low energy, dizziness, cravings, poor exercise tolerance.
The best sources:
Not all salt is created equal. Refined table salt is heavily processed and stripped of trace minerals leaving only sodium chloride. Look for clean, mineral-rich salts to adequately nourish the body.
Some of my favorites include:
- Vera Salt: sustainably harvested, rich in naturally occurring trace minerals, and free of the pollutants often found in conventional sea salt.
- Clean Sea salt: such as Diamond, Maldon, Saltverk, or Jacobsen’s, which retain magnesium, potassium, and calcium.
“One of the most important effects of sodium is that it tends to spare magnesium, which is likely to be lost during stress and hypothyroidism. If we eat salty foods when we crave them, we are able to retain our magnesium more easily. Sodium also helps to regulate blood sugar, for example by improving its absorption from the intestine. There is even evidence that sodium can spare protein, since, if there isn’t enough sodium to excrete into the urine to balance acids, the kidneys will waste protein to produce ammonium as an ionic substitute for sodium. But I think the most important point to remember is that it is essential for maintaining adequate blood volume, and that it is almost always unphysiological and irrational to restrict sodium intake, because reduced blood volume tends to reduce the delivery of oxygen and nutrients to all tissues, leading to many problems.” – from Dr. Ray Peat’s book Nutrition for Women (1993)