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