Reducing the sodium-potassium ratio in US diets to within recommended levels would require extraordinary efforts, according to a new study in the American Journal of Clinical Nutrition, as more than 99.9% of the population fails to meet guideline amounts for both minerals.
Lead researcher Dr. Adam Drewnowski and colleagues examined sodium, potassium and energy intakes for 12,038 adults using NHANES data from 2003-2008, identifying subpopulations to which different sodium recommendations applied, and estimated compliance based on two 24-hour dietary recalls. They found that joint recommendations for sodium and potassium were met by around 0.015% of the study population.
“The health consequences of excessive sodium intakes and a high sodium-potassium ratio are severe, leading to high blood pressure, heart disease, and stroke,” the authors wrote, adding that in recent analyses higher sodium-potassium ratios were associated with higher risk of mortality from all causes, as well as from heart disease.
“The fact that the proposed sodium and potassium goals are currently met by 0.015% of the US population should be an indication of potential problems ahead,” they wrote. “Dealing with 99.985% noncompliance will be a challenge for public health practitioners. Reducing the sodium content of the US diet may be a challenge for the food industry.
“…Future dietary guidelines might also note whether the proposed goals are intended as realistic or aspirational. Ideally, cost and feasibility analyses ought to precede or accompany the issuing of dietary guidelines.”
The 2010 Dietary Guidelines for Americans recommend an upper limit of 2,300mg of sodium per day, and 1,500mg for those with hypertension, diabetes, or chronic kidney disease and for those considered at risk of developing these conditions, including blacks and the over-50s. This lower threshold applies to about half of the US population, according to USDA figures.
The Centers for Disease Control and Prevention says that nine in ten Americans consume too much sodium, and it estimates average intake at around 3,300mg a day.
Meanwhile, the recommendation for potassium is 4,700mg a day, with estimated average intake at 2,400mg to 3,200mg, depending on age and gender. The authors said they were unaware of any previous research that has looked at simultaneous compliance rates with both sodium and potassium guidance.
“The current analyses point to the difficulty of complying with multiple nutrient requirements simultaneously,” they wrote, adding that even designing a theoretical approach to reducing sodium to under 1,500mg a day is only possible for certain individuals with lower than average energy needs.
Source: American Journal of Clinical Nutrition
First published ahead of print July 3, 2012 as doi: 10.3945/ajcn.111.025353.
“Reducing the sodium-potassium ratio in the US diet: a challenge for public health”
Authors: Adam Drewnowski, Matthieu Maillot, and Colin Rehm