Potassium
The main electrolyte inside cells, essential for blood pressure, heart and muscle function, and often lacking in the modern diet.
Potassium is the intracellular counterweight to sodium (extracellular). Together, they manage fluid balance, nerve transmission and muscle contraction (including the heart). Needs are high (~3.5 g/day) but rarely met.
The original angle (the real lever for blood pressure): we are constantly told to eat « less salt » against high blood pressure. But the sodium/potassium ratio often matters more than sodium alone. Increasing potassium:
- Helps the kidneys eliminate sodium
- Relaxes the walls of the blood vessels
- Lowers blood pressure
Studies suggest that increasing potassium can be as effective as cutting sodium for blood pressure. Yet this message is far less well known.
The inverted ancestral imbalance: our hunter-gatherer ancestors consumed enormous amounts of potassium (plants, ~10,000 mg/day) and little sodium. The modern diet has inverted this ratio: lots of sodium (ultra-processed foods) and little potassium (few plant foods). Our physiology, calibrated for the opposite, suffers.
Rich sources: banana (the cliché, but not the richest!), potato, spinach, pulses, avocado, sweet potato, beetroot, coconut water, dried apricots. In reality, vegetables and pulses often beat the banana.
Precaution: excess potassium (hyperkalaemia) is dangerous for the heart, but rare from food in healthy people. However, people with kidney failure or on certain medicines need to watch their intake, as their kidneys no longer clear potassium well. For them, medical advice comes first.