It's not just 'less salt': the sodium-to-potassium ratio that predicts blood pressure

For decades the salt message has been one-directional: eat less sodium. It is not wrong, but it is half the story. The mineral that opposes sodium — potassium — is chronically under-consumed, and the balance between the two turns out to predict blood pressure and cardiovascular risk better than sodium alone.

Why the ratio beats sodium in isolation

Sodium pulls water into the bloodstream and raises pressure; potassium promotes sodium excretion and relaxes vessel walls. Aburto and colleagues (2013, BMJ) showed in a large meta-analysis that increasing potassium lowered blood pressure and stroke risk independently of sodium. Cook and colleagues (2009) found the sodium-to-potassium ratio was more strongly associated with cardiovascular events than either mineral measured separately — which is exactly why the DASH diet raises potassium-rich foods at the same time as it cuts salt.

Two people can eat the same amount of salt and have very different blood pressure — the difference is often how much potassium is on the plate alongside it.

The targets that matter

The practical goal is a sodium-to-potassium ratio at or below 1.0 (by weight, mg to mg) — the level the DASH pattern tends to produce. Ratios of 2.0 and above are associated with elevated cardiovascular risk. In absolute terms that means keeping sodium under 2,300 mg/day (ideally nearer 1,500 mg for those managing blood pressure) while pushing potassium toward the adequate-intake figures of roughly 3,400 mg for men and 2,600 mg for women — from leafy greens, beans, potatoes, bananas, yoghurt and fish, not from a salt-shaker decision alone.

How Misi tracks both sides

Misi's Insights computes a dedicated Sodium:Potassium ratio for every day you log, with a target line at 1.0 and a risk line at 2.0, drawing on the sodium and potassium content of every logged ingredient plus any single-nutrient supplements you confirm. If you have logged blood pressure or lab data, the Labs tab bridges your average sodium intake against your systolic reading — and surfaces potassium-rich meals as the lever, rather than just telling you to eat less salt.

The practical takeaway

Before you agonise over hiding the salt-shaker, look at whether there is any potassium on your plate. Adding a fist of greens, a portion of beans or a potato to a meal often moves the ratio further than removing a pinch of salt — and it is a far easier habit to keep.

Misi is a coaching and wellness platform, not a medical service. If you have kidney disease or take potassium-affecting medication, do not increase potassium intake without medical advice.