October 20th, 2011

CDC and AHA Tussle Over Just How Bad the Salt Problem Really Is

No matter how you slice it, a lot of people in the U.S. consume too much sodium. But the CDC and the American Heart Association (AHA) disagree about just how bad the salt problem really is.

U.S. guidelines currently recommend that everyone keep their daily sodium intake below 2300 mg, but a large subpopulation, including people aged 51 or older, blacks, and people with hypertension, diabetes, or chronic kidney disease, should further restrict their sodium intake below 1500 mg. Now, a report from the CDC finds that nearly half the population (47.6%) should adhere to the more restrictive 1500-mg guideline.  The estimate is based on data from the National Health and Nutrition Examination Survey (NHANES).

In a statement issued by the AHA, however, AHA president Gordon Tomaselli says the CDC report is “too conservative in its suggestion that only 47.6 percent of American adults fit into the population group that should be consuming no more than 1500 mg a day of sodium.”

Clyde Yancy, a former AHA president, spells out the reason for the AHA position: “Given that most of us – as many as 90% – will develop high blood pressure with age, we all should be consuming less than 1500 mg a day of sodium, unless your healthcare provider has told you that this doesn’t apply to you.”

No matter the goal, Americans are consuming far too much salt, according to the CDC report. Even with the more conservative CDC guidelines, 98.6% of those with the more restrictive 1500-mg recommendation are exceeding their limit, while 88.2% of the rest of the population is exceeding the 2300-mg limit.

4 Responses to “CDC and AHA Tussle Over Just How Bad the Salt Problem Really Is”

  1. Robin Motz, M.D., Ph.D. says:

    When I was doing research in physics, we generally said that if researchers were arguing about the proper interpretation of experimental or observed data (e.g. in astronomy) then both conclusions/recommendations were suspect, and we should wait for further data. No one argues about the speed of light or the distance of the earth from the sun.

  2. Robin Motz, M.D., Ph.D. says:

    Blog discusses this point in depth at http://ghthomas.blogspot.com/2010/04/when-is-low-salt-diet-beneficial-if.html.

  3. Too my mind, this is a no brainer. The impact of a significant reduction in salt intake, particularly in populations vulnerable to hypertension (African-Americans, Asian-Americans, elderly patients, patients with CKD) and to the consequences of hypertension (stroke, heart failure, CKD) could be enormous, both in terms of outcomes, QOL, and cost. The increase morbidity and mortality associated with high salt intake has been demonstrated in epidemiological studies and other cohort studies. The potential economic benefit of salt reduction has been analyzed in excellent modeling studies published. Two such studies are referenced below.

    Projected effect of dietary salt reductions on future cardiovascular disease. Bibbins-Domingo K, Chertow GM, Coxson PG, Moran A, Lightwood JM, Pletcher MJ, Goldman L. N Engl J Med. 2010 Feb 18;362(7):590-9. Epub 2010 Jan 20.

    Association of sodium and potassium intake with left ventricular mass: coronary artery risk development in young adults. Rodriguez CJ, Bibbins-Domingo K, Jin Z, Daviglus ML, Goff DC Jr, Jacobs DR Jr. Hypertension. 2011 Sep;58(3):410-6. Epub 2011 Jul 25.

    Smith-Spangler CM, et al Population strategies to decrease sodium intake and the burden of cardiovascular disease: a cost-effectiveness analysis.

    Barry Massie, M.D., Professor of Medicine, University of California San Francisco

    Competing interests pertaining specifically to this post, comment, or both:

  4. Suggesting salt reduction is not likely to work. We can demand that processed foods contain less salt, we can use the bully pit to encourage people to use less salt, but we cannot put a meter on the salt seller in the kitchen or on the table. You will have great difficulty to convince a Cajun like me to eat low salt gumbo, boudin, etouffee, or red beans and rice!

    If dietary sodium is this big a problem, perhaps we need to start using clorthalidone sooner. If we put every young person with a BP >120/80 on 12.5 mg of chlorthalidone, we would have the same net effect as demanding a dramatic reduction in sodium consumption. Compliance with taking a small, inexpensive pill would be much better than compliance with changing lifelong dietary patterns. In addition, we would see the bonus of stronger bones and fewer kidney stones.

    Competing interests pertaining specifically to this post, comment, or both: