Legacy AI grade · Sources dated 2026-06-01. Not expert reviewed. Coverage is limited to the listed sources. About the new summary workflow
Potassium for Hypertension
Increasing potassium intake modestly lowers blood pressure in people who have hypertension, but the strong evidence is for dietary potassium and potassium-based salt substitutes rather than high-dose supplement pills, and it carries real risks for some groups.
Why this grade7-layer evidence engine
Multiple meta-analyses converge on a genuine, if modest, effect. The WHO-commissioned review of 22 randomized trials (PMID 23558164) found that higher potassium intake lowered systolic pressure by about 3.5 mmHg and diastolic by about 2 mmHg, an effect confined to people with hypertension, and was linked to roughly 24% lower stroke risk. A 2017 meta-analysis of 23 trials (PMID 28419159) reported similar reductions (SBP about 4.25 mmHg) in essential hypertension. The large SSaSS trial of nearly 21,000 adults (PMID 34459569) showed a potassium-enriched salt substitute cut stroke, cardiovascular events and death by 12 to 14% with no excess hyperkalemia.
The grade stays at preliminary rather than higher because the robust evidence is for dietary potassium and salt substitutes, not the low-dose (~99 mg) potassium pills sold on shelves, and the benefit is conditional. A dose-response analysis of 32 trials (PMID 32500831) found a U-shaped curve: the effect is concentrated in hypertensive people with high sodium intake, while excess potassium adds nothing and may even raise pressure in those already on blood-pressure drugs.
Regulators and clinics endorse the dietary route but stay cautious. The FDA permits a qualified claim that potassium-rich, low-sodium diets may reduce hypertension and stroke risk; WHO strongly recommends getting more potassium from food; and the UK NHS, Mayo Clinic, Cleveland Clinic and Harvard Health all advise food first. All warn that people with kidney disease or those taking ACE inhibitors, ARBs or potassium-sparing diuretics can develop dangerous hyperkalemia and need medical supervision.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.603
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status