What does it do?
Potassium supports fluid balance, nerve signalling and muscle contraction. Higher food potassium intake with reduced sodium may help blood-pressure control.
Where can I get it in food?
Beans, potatoes, leafy greens, vegetables, fruit and yogurt.
When might a supplement make sense?
Foods are generally the preferred source. Potassium pills are usually NOT needed for healthy people with a varied diet; prescribed replacement is a different situation.
What should I be careful about?
Potassium supplements and potassium-based salt substitutes can cause dangerously high blood potassium in people with kidney disease or those taking ACE inhibitors, ARBs or potassium-sparing diuretics.
How does this connect with Blue Zones?
Beans and produce supply potassium as part of wider dietary patterns. The food matrix and sodium balance matter—there is no evidence that taking potassium pills reproduces Blue Zone longevity.
Read the original evidence
NIH Office of Dietary Supplements — Potassium fact sheet ↗
Educational information only. This primer explains nutrient biology; it does not promise longevity or offer personalized medical advice. Last reviewed for source alignment: November 2026. Editorial review recommended before publication.