Tuesday, July 12, 2011

CDC Study: Risks Of High Sodium, Low Potassium Diets

 

 

# 5686

 

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Photo Credit – CDC Grand Rounds

 

 

Another salvo in the excess-dietary-sodium wars was fired yesterday with the release of a study by the CDC, Emory University, and Harvard University on the effects of high sodium and low potassium diets on all-cause and coronary death rates.

 

As you may recall, last April I blogged on a CDC Grand Rounds presentation called Sodium Reduction: Time for Choice, and mentioned my own attempts to lower my sodium intake.

 

Last week, we looked at a conflicting and controversial Cochrane review called:

 

Reduced dietary salt for the prevention of cardiovascular disease

Taylor RS, Ashton KE, Moxham T, Hooper L, Ebrahim SPlain Language Summary

Cutting down on the amount of salt has no clear benefits in terms of likelihood of dying or experiencing cardiovascular disease

 

Patients with congestive heart failure, they cautioned, who were on a sodium restricted diet saw an increase in all-cause deaths.

 

I discussed the all-too-frequent dilemma posed by conflicting scientific studies last week in A Decided Lack Of Scientific Certainty.

 

While the debate rages on (The Salt Institute is taking considerable umbrage over this latest research, calling it `Highly flawed’), today’s study – which appears in the Archives of Internal Medicine – strongly suggests that: 

 

Americans who eat a diet high in sodium and low in potassium have a 50 percent increased risk of death from any cause, and about twice the risk of death from heart attacks. - (Lede from CDC Press Release)

 

You can read the entire Press Release here, but a few excerpts include:

 

 

"The study's findings are particularly troubling because U.S. adults consume an average of 3,300 milligrams of sodium per day, more than twice the current recommended limit for most Americans," said Elena Kuklina, M.D., Ph.D., an investigator on the study and a nutritional epidemiologist with CDC's Division for Heart Disease and Stroke Prevention.

 

"This study provides further evidence to support current public health recommendations to reduce sodium levels in processed foods, given that nearly 80 percent of people's sodium intake comes from packaged and restaurant foods. Increasing potassium intake may have additional health benefits."

 

In general, people who reduce their sodium consumption, increase their potassium consumption, or do both, benefit from improved blood pressure and reduce their risk for developing other serious health problems.

 

The abstract to the study is available on the Archives of Internal Medicine site:

 

Sodium and Potassium Intake and Mortality Among US Adults

Prospective Data From the Third National Health and Nutrition Examination Survey

Quanhe Yang, PhD; Tiebin Liu, MSPH; Elena V. Kuklina, MD, PhD; W. Dana Flanders, MD, ScD; Yuling Hong, MD, PhD; Cathleen Gillespie, MS; Man-Huei Chang, MPH; Marta Gwinn, MD; Nicole Dowling, PhD; Muin J. Khoury, MD, PhD; Frank B. Hu, MD, PhD

Arch Intern Med. 2011;171(13):1183-1191. doi:10.1001/archinternmed.2011.257

 

 

This study basically followed 12,267 U.S. adults, tracking their sodium/potassium consumption, and correlated that with death rates (and their causes) over a 15 year follow-up period.

 

They found those who had the highest sodium intake combined with the lowest potassium intake were twice as likely to die from CVD (Cardiovascular Disease), and 50% more likely to suffer any any-cause death.

 

It should be noted that the study did not find a significant link between excess sodium consumption alone and CVD, stating:

 

“Sodium intake was not statistically associated with CVD or IHD mortality.” 

 

The go on to state, however, that:

 

"The non-significant associations between sodium intake and CVD mortality observed in our study do not undermine a well-established relationship between sodium intake and high blood pressure or the potential benefits of sodium reduction at the population level.”

 

 

Given the vehement protestations of the Salt Institute, and the lack of a smoking salt shaker in this study, how should the public regard this latest information?

 

Accepting that scientific certainty is often an elusive, and sometimes impossible goal – and that what may apply to the population as a whole may not apply to each and every individual . . .

 

. . . the preponderance of evidence right now suggests that excess sodium consumption poses a significant health risk.

 

Increasing your potassium intake may help mitigate some of those risks, but this study strongly suggests that the best strategy is probably to both reduce sodium and increase your potassium intake.

 

The CDC advises

 

Adults can improve their health by knowing recommended limits for daily sodium intake, choosing foods like fresh or frozen fruits and vegetables, and unprocessed or minimally processed fish, meat or poultry, low-fat milk or plain yogurt, asking for foods with no or low salt at restaurants, and reading the nutrition labels of foods before purchasing can improve health for all adults.

 

 

If you are still unsure, you should discuss it with your health care practitioner. But the odds are, they will side with the CDC on this issue, and advise you to take a step back from your salt shaker.