Patrick J. Skerrett

Does eating less salt lead to heart disease? New JAMA study is more wishful thinking than a diet changer

A paper in today’s Journal of the American Medical Association (JAMA) offers the contradictory conclusion that taking in less salt—a key goal of U.S. health and dietary recommendations—is bad for you. But before you roll your eyes and groan about flip-flops in science, know that this study isn’t the kind of work on which you or anyone should base dietary decisions.

In this study of 3,681 men and women from Belgium, Bulgaria, Italy, Poland, Romania and Russia whose health was followed for eight years, participants with the lowest sodium excretion (which is a good measure of sodium intake) were 56% more likely to have died from cardiovascular disease than those with the highest sodium excretion. Among the nearly 2,100 participants with normal blood pressure at the study’s start, sodium excretion (sodium intake) had no effect on the development of high blood pressure.

These are startling findings. If true, they would undercut major programs by the U.S. government to reduce Americans’ intake of salt—the main source of sodium—from prepared and processed foods and at home.

But the results and conclusions probably aren’t valid, or at least don’t apply to most Americans. Flaws in the JAMA study include the young age of the population (49 at the study’s end), short duration, and too few deaths and cardiovascular problems to make valid comparisons. (For a more in-depth evaluation, see the critique of the study on The Nutrition Source, from the Harvard School of Public Health.)

The only way to settle the ongoing debate about salt intake, blood pressure, and cardiovascular disease is with a large trial in which half of the volunteers are randomly assigned to follow a low-sodium diet and the other half are randomly assigned to a “usual” diet (which in the U.S. means high sodium), and the participants are followed for years. It isn’t likely that such a study will ever happen.

I’m still swayed by the weight of the evidence supporting a connection between taking in too much salt and the development of high blood pressure, stroke, heart attack, heart failure, and other cardiovascular conditions. But if you are leery about the low-salt message and serious about preventing heart disease, there are other things you can do to keep your blood pressure from creeping higher:

Exercise is a proven way to maintain a healthy blood pressure or lower high blood pressure.

Losing weight if you are overweight can help. Among overweight people, losing just 5 percent of body weight significantly cuts the risk of developing high blood pressure.

A healthy diet is another way to keep blood pressure in check or lower it without medication. The DASH diet—eating more fruits, vegetables, whole grains, and low-fat dairy foods, and cutting back on animal fats, sweets, and sugary beverages—has been proven to reduce blood pressure.

Comments:

  1. Evert Hartman

    Salt much salt is not good for people.
    Salt is good for the road.

  2. Richard Moss

    This is a cautionary tale about accepting research results before actually checking the procedure that was used to produce those results. I have to admit, though, it leaves me wondering who is right.

    Richard Moss, Editor, PE Update.com

  3. Bailim Denis

    I came across this after my grand ma died when she was told to be on low salt diet and this never satisfied after what i read about the salt intake in other individual, however my second concern is about hernia. How does it comes about? and could it be that the tendency of scrotum pulling and lower abdominal pain associated with gross ill health?

  4. Carole Book

    Interesting to stumble over this post because my mum had been told to reduce her salt intake due to high cholestrol, she was then tested a few months later and told that her salt levels were really low and she needed to start taking more!

    • Gordon Barnes

      Hi Carol depends on your source of Salt . The processed salt you buy from the supermarket is “INERT” I call this rubbish salt. However, the Sodium Chloride in Himalayan sea salt is “unprocessed “, besides being balanced with Potassium, it is in a highly charged state and like things in a highly charged state, it is not static or Inert. It will not store itself in your organs or affect your kidneys, but pass on through you as natural salts are meant to do. The Romans used to pay their employees in natural salt as it was highly prized health giving product.

      We are told to avoid salt by uniformed doctors when we have heart disease. Again, years of processed salt builds up in organs (and in the heart) and you’re ripe for edema (the collection of fluids). The only person who has to watch her/his salt intake is the person with a high degree of renin in her/his blood stream.

  5. James

    I would be more interested in the results of your suggested trial than edging on the side of the JAMA study. The JAMA report does nothing to inspire my ‘mind’ or push me towards eating a ‘normal’ amount of salt, as opposed to my usual low sodium diet.

    James
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