This review looks at the available evidence to see which of high Sodium (Na+), high Potassium (K+) or a high Potassium/Sodium ratio is most beneficial for our heart health.
Comparing the results from several population, and other types of studies, the authors concluded that irrespective of Sodium (table salt) intake the ratio of Potassium/Sodium intake was the critical factor in lowering Blood Pressure (BP) and reducing Cardiovascular (CVD) and Kidney disease:
“Potassium has a high homeostatic priority because of its critical importance in determining membrane potential and, thus, nerve and muscle function”.
Across all age groups, genders and racial types a higher K+/Na+ ratio, from food or Potassium salt supplementation, was found to:
- decrease the risk of CVD for all-cause morbidity and mortality (stroke deaths and ischemic heart disease);
- lower BP and medication (hypertension);
- reduce Sodium retention;
- reduce blood glucose levels;
- and slow the decline in renal function in chronic disease.
In one study, comparing a low-Na+/high-K+ diet to other diets and the DASH diet:
“The DASH diet had the largest effect, reducing systolic and diastolic BPs by 7.6 and 4.22 mmHg, respectively. In comparison, the low-Na+/high-K+ diets decreased systolic and diastolic BPs by about half as much as the DASH diet, and the other diets had even smaller effects.”
For people with chronic kidney disease this benefit is not found:
“A 2016 study addressing the effects of dietary Na+ and K+ on the progression of patients from chronic kidney disease to end-stage renal disease, or death, concluded that progression is reduced when chronic kidney disease patients consumed the lowest quartiles of Na+ and K+ , suggesting that as the kidney fails, and medications that affect Na+ and K+ transport are added, the renal capacity to regulate K+ homeostasis is compromised and Potassium is no longer beneficial”.
In conclusion the authors found that raising dietary Potassium blunts the effects of high dietary Sodium, especially in overweight and aging adults. They recommend a general strategy of modest Sodium restriction with increasing Potassium intake to control BP, prevent kidney disease and stroke, and reduce CVD mortality. Costs are a factor in community outcomes because Potassium rich diets are associated with higher costs, while higher Sodium diets are not. Adding foods rich in Potassium, like fruit and veges, was effective in reducing BP as was a 65% NaCl-25% KCl-10% MgSO salt substitute.
From: “Cardiovascular benefits associated with higher dietary K+ vs. lower dietary Na+: evidence from population and mechanistic studies. McDonough et al”.
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