Effect of Increased Potassium Ingestion on Cardiovascular Health
Increased potassium intake reduces stroke risk and lowers blood pressure (both systolic and diastolic), making option A the correct answer. 1, 2
Effects of Potassium on Stroke Risk
Potassium intake has a significant protective effect against stroke:
- In prospective studies, higher potassium intake is consistently associated with reduced risk of stroke 1
- A meta-analysis demonstrated that increased potassium intake was associated with a 24% lower risk of stroke (risk ratio 0.76,95% CI 0.66 to 0.89) 2
- One trial using potassium-enriched salt in elderly Taiwanese men showed a 50% reduction in mortality from cerebrovascular disease (RR 0.50) 1
- The stroke protection from potassium appears to work through both BP-dependent and BP-independent mechanisms 1, 3
Effects of Potassium on Blood Pressure
Potassium lowers both systolic and diastolic blood pressure:
- Meta-analyses show that increased potassium intake reduces systolic BP by 3.49 mm Hg and diastolic BP by 1.96 mm Hg in adults 2
- The effect is more pronounced in hypertensive individuals 1, 4
- In hypertensive patients, a dose-response relationship exists: each 0.6 g/day increase in potassium intake reduces systolic BP by 1.0 mm Hg and diastolic BP by 0.52 mm Hg 4
- With an intake of 4.7 g (120 mmol) of dietary potassium per day, average BP reduction is 8.0/4.1 mm Hg, with greater effects in blacks than in Caucasians 4
Potassium's Mechanism of Action
Potassium's cardiovascular benefits work through several mechanisms:
- Potassium blunts the effect of sodium on blood pressure 1
- A lower sodium-potassium ratio is associated with lower BP than corresponding levels of either mineral alone 1
- Potassium appears to reduce the intrinsic susceptibility to cerebral artery lesions even at the same level of blood pressure 3
- The protective effect against stroke appears to be independent of other dietary variables and cardiovascular risk factors 5
Clinical Recommendations
Based on the evidence:
- The American Heart Association recommends potassium intake of at least 4,700 mg/day (120 mmol/day) 1
- Increased potassium intake is particularly beneficial for:
- Potassium from food sources (fruits, vegetables, nuts) is preferred over supplements 1
Important Caveats
- Increased potassium intake may be risky in patients with advanced chronic kidney disease (stages 3-5), especially diabetics 6
- Caution is needed in patients using potassium-sparing diuretics or potassium supplements 1
- The US Dietary Guidelines for Americans recommend potassium intake of 4,700 mg/day, but most Americans consume far less 1
The evidence clearly demonstrates that increased potassium intake reduces stroke risk and lowers both systolic and diastolic blood pressure, not increases them, making option A the correct answer.