Header graphic for print

Food Safety News

Breaking news for everyone's consumption

New Study Shakes Medical Advice on Low-Salt Diets

Salt is commonly viewed as the enemy of a healthy diet. However, liberal use of the salt shaker might actually be more of a cure than a curse when it comes to human health, according to new research.

The study, published Tuesday in the Journal of the American Medical Association (JAMA), followed health trends in 3,681 individuals over a median of almost 8 years, and found that a higher sodium intake was actually associated with a lower incidence of cardiovascular disease (CVD), and that the amount of salt consumed had no correlation with hypertension.

Participants were divided into three groups based on their salt consumption: low, medium or high. Results showed a higher rate of deaths from cardiovascular disease (4.1 percent) among the low-salt population than among the high-salt group, only 1.9 percent of whom died of cardiovascular disease.

Hypertension rates were found to be the same between people in the high-salt category and those in the low, suggesting that salt intake does not increase the risk of high blood pressure.

“We started this study more than 25 years ago, and in all our studies, it was almost impossible to find an association between blood-pressure and 24-hour sodium excretion,” said Dr. Jan A. Staessen, professor of medicine at the University of Leuven in Belgium and one of the study’s authors, in a news@JAMA interview.

This research, which suggests that salt may not be detrimental to health after all, and might even contribute to a decrease in CVD-related mortality, runs counter to the government’s current nutritional policy, which has been pushing for a reduction of salt in the American diet on the theory that it’s dangerous in large doses.

Indeed, the most recent Dietary Guidelines issued by the Food and Drug Administration recommend a daily intake of 2,300 mg of sodium for healthy individuals, a reduction of almost 1/3 from the 3,400 mg Americans now consume, according to the Mayo Clinic.

And the new U.S. Department of Agriculture rules for the National School Lunch Program, set to go into effect in 2012, limit the amount of sodium allowed in schools lunches to around 700 mg.

In light of this latest study, as well as previous research, the industry’s Salt Institute says it’s time for the government to change course.

“This study confirms previous research that reductions in sodium lead to an increased risk of disease and death,” said Lori Roman, president of the Institute, in a statement. “Therefore, we call on government agencies to stop their population-wide sodium reduction agenda and amend the Dietary Guidelines on sodium,” Roman said.

The previous studies Roman refers to include one indicating that low sodium intake has a detrimental effect on the elderly, one that found babies with low birth weight to also have low amounts of sodium in their blood, and a 2010 study from Harvard showing no connection between hypertension rates and sodium consumption.

The Salt Institute cautions that FDA should not wait until the next revision of the Dietary Guidelines in 2020 to change its sodium recommendations, because doing so would put people at risk.

“We don’t feel like we can wait another 10 years for the next set of dietary guidelines. This train is going down the track, and we believe this study is a can’t-miss red light saying whoa, let’s put the brakes on. Let’s at least look at all the available evidence, and let’s do some more research before we actually harm the U.S. population,” said Mark O’Keefe, the Institute’s communication director, in an interview with Food Safety News.

But others say that salt-lovers shouldn’t salt their chicken before more research hatches.

“They took one urine sample at one point of time and took a hugely broad brush and made conclusions for the world,” said Dr. Randall Zusman of Massachussettes General Hospital Heart Center in an interview with CommonHealth. Zusman says that people’s diets vary from day to day, and that the average of 5 urine samples collected per person for this study might not reflect their normal salt intake patterns.

In addition, observational studies such as this show only a correlation, but cannot prove cause and effect between lower salt consumption and heart disease, Dr. Laura Svetkey, director of the Duke Hypertension Center, told the Boston Globe.

Zusman says the study could be dangerous if seen as a blanket go-ahead to start popping pickles. When he recommends that patients decrease their salt intake, he says, it’s not just to decrease their blood pressure, but to help them avoid negating positive effects of medication.

And for the healthy population, traditionally salty foods are also often fatty or loaded with carbohydrates, making them an unhealthy option regardless of sodium content, he adds.

O’Keefe disagrees. He says that salt actually contributes to making healthy foods such as broccoli more flavorful and therefore more appealing, particularly to kids.

So now, the question: to take the table salt off the table, or leave it?

Staessen says his study should be treated as a jumping-off point for further research on the effects of sodium on cardiovascular disease.

“What one needs is a long-term interventional study to look at cardiovascular complications,” he says.

And Zusman sees this study as promoting the debate on the effects of salt, rather than ending it.

“The most important thing is that [the authors] are hypothesis-generating. They’re suggesting that perhaps we don’t understand as much as we thought we did about salt, cardiovascular disease and blood pressure,” he says.

© Food Safety News
  • http://www.healthyfoodcoalition.org hhamil

    And during the last several years of his life, my father, who was a physically vigorous man until the last year of his life, had terrible muscle cramps. Why? Almost certainly because he followed medical advice and limited himself to a low sodium diet. The result? Too little sodium in his body led to extremely painful muscle cramps.
    I thank Food Safety News for informing us of this study and the controversy it is raising. I hope that its implications will result in changes in the way that FSN reports on food safety issues.
    This is a perfect example of the 180 degree reversals that are necessary because of the hubris of what western culture labels as “science,” particularly, “medical science.”
    I hope that self styled food safety advocates will be chastened by it.
    For example, at present, they advocate regulation that requires those of us who produce and distribute the food they eat to use processes (e.g., Hazard Analysis and Risk-based Preventive Control plans) for which there is little or no actual evidence to show they make a material difference in the safety of the food in the instances to which the advocate want them applied. Why should Section 103 have been included in the Food Safety Modernization Act? Because of a longstanding recommendation made by an association of microbiologists and pushed by “experts,” many of whose academic training are law and very little science. And their logic? Because it is “science based!” That’s an a priori argument NOT scientific logic.

  • Michael Bulger

    I took a look at the study and thought a few things were worth pointing out.
    First and foremost, the levels that the researchers used to group the subjects. The mean sodium levels were all above 100 mmol. That’s higher than recommended by the USDA, WHO, EU, etc.
    The authors of the study also outline a few of their limitations. The first is that the 24-hour excretion measurement may not accurately indicate the habitual intake of the individuals.
    They continue by noting their study population was “relatively young…leading to a potential underestimation of the risk of excessive sodium intake.” Also, the study included only white Europeans.
    They conclude by stating that their results “do not negate the blood pressure−lowering effects of a dietary salt reduction in hypertensive patients.”
    In the United States, the DGAC reports that “hypertensive individuals, Blacks, and middle-aged and older adults” (those not featured in this latest study and at the highest risk) comprise about 70% of the population.
    Added note: The 2010 DGAC reviewed the 12 latest primary studies on the effects of sodium reduction on blood pressure. They found, “In total, a significant reduction in either systolic or diastolic blood pressure occurred in all but one of these studies, and significant reductions in both systolic and diastolic blood pressure in five studies.”

  • Ken

    Muscle cramps are typically caused by an imbalance of electrolytes and/or not consuming enough fluids every day.

  • Allan

    The salt controversy has been around for quite some time:
    http://www.nasw.org/1999-science-society-awards
    Scroll down to the bottom of the page to read the PDFs.

  • Doc Mudd

    This study supports conclusions from a rigorous meta-analysis, also published in JAMA:
    http://jama.ama-assn.org/content/279/17/1383.full?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=sodium&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT
    When it comes to preventing cardiovascular disease, blanket recommendations to restrict salt intake amount to much ado about pure conjecture. Controlling an existing hypertensive disorder – sure control your salt intake but for everyone else our risk of developing cardiovascular disease is about the same regardless of salt in our food.
    Why all the passion around this topic? Salt is hardly worth working your shorts into a bunch over…unless you’re getting too little.

  • http://www.healthyfoodcoalition.org Harry Hamil

    And during the last several years of his life, my father, who was a physically vigorous man until the last year of his life, had terrible muscle cramps. Why? Almost certainly because he followed medical advice and limited himself to a low sodium diet. The result? Too little sodium in his body led to extremely painful muscle cramps.
    I thank Food Safety News for informing us of this study and the controversy it is raising. I hope that its implications will result in changes in the way that FSN reports on food safety issues.
    This is a perfect example of the 180 degree reversals that are necessary because of the hubris of what western culture labels as “science,” particularly, “medical science.”
    I hope that self styled food safety advocates will be chastened by it.
    For example, at present, they advocate regulation that requires those of us who produce and distribute the food they eat to use processes (e.g., Hazard Analysis and Risk-based Preventive Control plans) for which there is little or no actual evidence to show they make a material difference in the safety of the food in the instances to which the advocate want them applied. Why should Section 103 have been included in the Food Safety Modernization Act? Because of a longstanding recommendation made by an association of microbiologists and pushed by “experts,” many of whose academic training are law and very little science. And their logic? Because it is “science based!” That’s an a priori argument NOT scientific logic.

  • Michael Bulger

    At issue is the fact that the majority of people in the United States are hypertensive or at-risk of hypertension. This is combined with the fact that the large majority of Americans consume above the recommended levels of sodium. Approx. 70% of this is from processed-foods (not as widely consumed during the 1970s and 80s, which is where most of the data for Mudd’s study comes originates).
    This latest study is interesting. However, given its limitations, the fact that the risk-factor is significantly higher for most Americans, the presumed increase in consumption of sodium since Mudd’s authors made their recommendations, and the unflappable understanding that high-blood pressure is reduced with sodium intake, it is understandable why the worldwide recommendations are to limit salt in our diets. Processed foods are a good place to start.

    • Chudleigh

      The very slight and barely measurable reduction in hypertension associated with reduced salt is a transient effect with no consequence to the overall fatal results of reduced salt.
      The AMA study is confirmed daily in the longevity of patients and test subjects who consume the most salt.

  • Doc Mudd

    “Processed foods are a good place to start.”
    Ah, and there is the underlying quack agenda – all of this goofy over-acted angst has nothing to do with sodium or salt or the price of tea in China…and certainly nothing to do with the public health.
    Long ago I stopped taking unsolicited medical advice from ambitious amateurs. In fact, it is primarily to that cautionary practice I attribute my legendary virility and astonishing longevity. Damned quacks. Pass the salt, will ya?

  • Michael Bulger

    That is not the agenda, that is the most obvious solution to the problem. If Americans are consuming most of their sodium in the form of processed foods, then an across-the-board reduction of sodium levels in processed foods would have the most impact and the most benefit for the health of Americans.
    I’m going to refrain from acknowledging your comments any further. There are a few attributes you seem to have failed to acquire, as so recognized by virtually every regular poster on FoodSafetyNews. Happy Cinco de Mayo, “Mudd”.

  • Doc Mudd

    Oh, rubbish…
    …it is (the agenda)
    …it’s not (a solution)
    …you won’t (refrain from taking cheap shots by foisting ignorant amateur medical opinions on a gullible public).
    Whatever you do, don’t let the scientific research sway your amateur opinion. Stay true to your agenda. Quack on, Bro!

  • Michael Bulger

    Don’t shoot the messenger. The (professional) American Medical Association’s position?
    “The AMA has long-held policy supporting a reduction of sodium in processed foods and restaurant meals to lower sodium intake and reduce the risk for cardiovascular disease.
    ‘Excessive sodium intake causes blood pressure to rise, increasing the risk of heart attacks and strokes,’ AMA Board of Trustee member Edward L. Langston, MD, said in an AMA statement. ‘Much of the sodium in Americans’ diets is hidden in processed foods and restaurant meals.’”
    http://www.ama-assn.org/ama/pub/amawire/2011-january-19-general_news2.shtml

  • Mike

    Looks like the sodium=hypertension correlation has some opposition. Pass the salt, I need some for my pickle!

  • http://www.beautifulreviews.com/DrDenese.html Dr Denese

    That sucks, harry. Your dad should’ve sued. I totally believe that too little salt is bad for you, but this study’s ridiculous amount of flaws doesn’t help them prove their point. First off, all the test subjects were white, in their 40s, and had no history of cardiovascular disease or any serious medical conditions for that matter. I even read somewhere that half of the 50 that died on the low salt diet were heavy smokers anyway… something that the test neglected to disclose in the study.