Diets high in salt or sodium and low in potassium are par for the course for most Americans, in large part because of an increased reliance on processed and refined foods. The Third National Health and Nutrition Examination Survey (NHANES III) evaluated a representative sample of 16,562 Americans adults using 24hr dietary recall to estimate their intake of a wide variety of nutrients. The NHANES data found on average American men and women were consuming 4323mg and 2918mg of sodium daily, respectively. This is well in excess of recommendations from the Center for Disease Control, the American Heart Association, and US Dietary Guidelines all of which suggest no more than 1500 mg for most adults. The potassium intake also fell well short of the recommended 4700 mg for both men (3373mg) and women (2433mg).1 The DASH-Sodium clinical trial clearly demonstrated that decreasing salt and/or increasing potassium-rich foods in the diet led to a significant drop in blood pressure for most people with elevated blood pressure over the course of several weeks. 2 There is also compelling evidence that an excessive sodium to potassium ratio creates a physiological stress on the body that plays a central role in the development of hypertension.3
A recent study that used data from 1988 NHANES III and data from linked mortality files over the next 14.8 years on average examined the long-term impact estimated dietary sodium and potassium intake on CVD and total mortality. This study excluded people with a history of CVD and/or those who were following a salt-restricted diet after being diagnosed with hypertension. They found increasing dietary sodium by 1000mg/day increased total mortality by 20% whereas an increase of 1000mg of potassium/day reduced total mortality by about 20%. Given the difficulty in accurately measuring sodium and potassium intake with a single 24hr diet recall it is likely that the real impact on total and CVD mortality are even greater than observed in this study. The authors of this study conclude: “Our findings suggest that a higher sodium-potassium ratio is associated with significantly increased risk of CVD and all-cause mortality, and higher sodium intake is associated with increased total mortality in the general US population”. 4
Bottom Line: The preponderance of scientific evidence now link the typical modern diet high in processed refined foods (most with a lot of added salt) to increased blood pressure and a markedly increased risk of both CVD events and total mortality.
By James J. Kenney, FACN, PhD.
1. Institute of Medicine. Panel on Dietary Reference Intakes for Electrolytes and Water. Nat Acad Press 2005
2. N Engl J Med 2001;344:3-10
3. N Engl J Med. 2007;356:1966-78
4. Arch Intern Med 2011.171:1183-91
Stephanie Ronco has been editing in a professional capacity for the past 10 years. In addition to her work as an editor, Ronco has also served as a ghostwriter and writing tutor. A voracious reader, Ronco loves watching language evolve and change. When she’s not delving into her latest project, Ronco can be found teaching acting classes, performing in community theater, or sailing with her husband.