Sodium
An electrolyte mineral essential for fluid balance, nerve transmission and muscle contraction, but eaten in large excess through salt in the modern diet.
Sodium (Na) is the main extracellular electrolyte. Table salt (sodium chloride, NaCl) is about 40% sodium. Real physiological needs are low (about 1.5 g sodium/day), but average consumption often exceeds 3.5 to 4 g.
An original angle (nuance in the salt debate): the message “less salt = better” is more nuanced than the received wisdom. The relationship between sodium and mortality follows a J-shaped curve: both too much sodium AND too little are associated with increased risks. The sweet spot lies in a moderate range, not at the absolute minimum.
Above all, about 70 to 75% of the sodium we eat does NOT come from the salt shaker but from hidden processed foods: bread, charcuterie, cheese, ready meals, sauces. Cutting the salt you add at the table therefore has a limited impact; cutting ultra-processed foods is far more effective.
The real issue is the sodium/potassium ratio. The modern diet is high in sodium and low in potassium (the opposite of our ancestral physiology). Increasing potassium (vegetables, fruit, pulses) is often more beneficial for blood pressure than just cutting sodium.
“Salt-sensitive” people (a fraction of the population) react strongly to sodium in their blood pressure; others are barely sensitive. Hence varying individual responses.