Granal et al. 2025 — Effect of changes in potassium intake on blood pressure
Citation
Granal M, Sourd V, Burnier M, Fauvel JP, Gougeon A. “Effect of changes in potassium intake on blood pressure: a dose–response meta-analysis of randomized clinical trials (2000–2024).” Clinical Kidney Journal 2025;18(7):sfaf173. doi:10.1093/ckj/sfaf173. Published online June 28, 2025.
Study design
Dose-response meta-analysis of 10 randomized clinical trials published between 2000 and 2024, examining changes in potassium intake (via dietary modification or supplementation) and blood pressure outcomes. Total participants across the 10 trials: n=684 (342 intervention, 342 control). Potassium intake was quantified using 24-hour urinary potassium excretion as the validated biomarker of intake (the gold standard; avoids recall bias). Of 10 included trials: 4 enrolled non-hypertensive participants; 6 enrolled hypertensive participants.
Key findings
Per +50 mmol/day potassium increase
| Population | Systolic BP change | Diastolic BP change |
|---|---|---|
| Non-hypertensive | −0.5 mmHg | −0.12 mmHg |
| Hypertensive | −5.3 mmHg | −3.62 mmHg |
The dose-response relationship was best fit by a linear model — no threshold or saturation was detected within the studied range.
Clinical significance
- A +50 mmol/day increase in urinary potassium excretion corresponds roughly to consuming an additional 3–4 servings of high-potassium foods (e.g., 200 g banana ≈ 11 mmol; 100 g avocado ≈ 14 mmol; 100 g cooked lentils ≈ 14 mmol) or to partial salt-substitute usage (as in SSaSS)
- The ~−5 mmHg systolic reduction in hypertensives is clinically meaningful — equivalent to a low-dose antihypertensive
- Supports guideline recommendation of >3.5 g/day (~90 mmol/day) potassium for adults per WHO/ESH
Mechanistic framing
The hypertension-selective amplification is consistent with pathophysiology: in hypertension, impaired renal Na⁺ excretion creates a setting where ROMK-channel-mediated potassium-driven natriuresis has greater pressure-lowering impact. The VSMC hyperpolarization effect of potassium is also more consequential when vascular tone is chronically elevated.
Limitations
- Only 10 trials, reflecting the relative paucity of dose-response potassium RCTs (many trials use binary high/low comparisons rather than quantified dose ranges)
- 24-hour urinary potassium is the gold-standard intake biomarker but requires participant compliance with collection protocol; real-world compliance varies
- Most trials were <6 months; long-term BP response over years is less well characterized
- Trial populations were predominantly white and European/North American; generalizability to other populations requires confirmation
Relationships
- Companion to: kong-2025-sodium-umbrella-review (sodium-focused umbrella review)
- Context: neal-2021-ssass-salt-substitute (SSaSS salt-substitute RCT delivered ~+50 mmol/day K via the KCl component)
- See also: sodium-restriction (companion cation section)