Is It Safe to Put the Salt Shaker Back on the Table?

Thursday Feb 26 | BY |
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Do not throw salt in your heart!

New evidence suggests we’ve been all shook up over salt for no reason.

If you have heart disease in your family, you know the drill.

Put away the salt shaker.

It’s almost as natural as breathing.

I remember when my dad was diagnosed with high blood pressure. The salt left the dinner table, replaced by that Dash diet spice product. Dad hated it. He just wanted his salt back.

Turns out from what we know now that we probably could have given it to him without worry.

Despite the fact the American Heart Association still recommends less than 1,500 mg of sodium a day, recent scientific studies suggest that such low amounts won’t protect us from heart disease or death. In fact, in some cases, they may actually cause more health problems than they solve.

Is it time to put the salt shaker back on the table?

Why Did They Tell Us to Reduce Sodium in Our Diets?

Doctors suspected way back in the early 1900s that sodium had something to do with high blood pressure—a major risk factor for heart disease. French physicians at that time reported that restricting salt and salty foods helped patients with fluid retention and high blood pressure.

The theory goes that as we take in more salt (sodium), it disrupts the natural balance of sodium in the blood. The body responds by increasing water (fluid retention) to dilute it. More fluid makes it harder for the heart to pump the blood, though, and raises the pressure exerted against blood vessel walls, resulting in high blood pressure. Salt is also believed to irritate arteries and cause them to constrict, compounding the problem.

We can see sodium pulling water across membranes in the lab, so we know it happens—but does it always happen in the body? Scientists were convinced for decades. In the 1940s, a Duke University researcher named Walter Kempner, M.D., became well known when his extremely low-salt “Rice Diet” was found to help treat seriously ill patients with high blood pressure and other health problems like kidney disease and heart failure.

The theory got another boost in the 1970s when studies published by Lewis K. Dahl, from Brookhaven National Laboratory, showed that he could induce high blood pressure in rats fed the equivalent of over 500 grams of sodium a day—50 times the average intake (of 3.4 grams of sodium or 8.5 grams of salt a day). He also found that in certain areas with a high consumption of salt (like Japan), people had more incidences of high blood pressure and stroke. (It wasn’t determined the salt was the cause of the high blood pressure, however.)

At the time, these studies were taken as proof that a high-salt diet increased risk of hypertension, which in turn, increased risk of heart disease. In 1977, the U.S. Senate Committee released a report recommending Americans cut back on salt. That recommendation still permeates our culture today.

Studies Show Conflicting Results on Salt and High Blood Pressure

Meanwhile, scientific journals continued to publish studies showing that a low-salt diet could reduce risk of hypertension, which seemed to confirm the fact that cutting back on salt could lower risk of heart disease.

  • DASH diet helps: In 2001, for instance, the New England Journal of Medicine reported that when about 400 participants were assigned to eat either a regular diet or the DASH low-sodium diet for 30 days, those on the DASH diet lowered their blood pressure substantially.
  • Low sodium good for reducing prehypertension: In 2007, the British Medical Journal reported that participants between the age of 30 and 54 years who had prehypertension and were put on a low-sodium diet for 18 months or 36-48 months had a 25 percent lower risk of a cardiovascular event (like a heart attack or stroke) than those who didn’t cut back on sodium.

At the same time, however, other studies were coming up with conflicting results.

  • Sodium doesn’t make any difference: In 1988, for example, research from the Intersalt Cooperative Research Group published in the British Medical Journal reported that after testing over 10,000 people aged 20 to 59 years from 52 centers around the world, sodium levels were not significantly related to the prevalence of high blood pressure.
  • Sodium helps only those who already have high blood pressure: In 2004, the Cochrane Collaboration published a review of 11 studies showing that over time, low-salt diets provided extremely minimal reductions in blood pressure—specifically, by 1.1 mmHG in systolic (upper number) and 0.6 mmHG in diastolic (lower number) levels. They did note that people who took medications to reduce blood pressure were able to get off those medications on a reduced sodium diet as compared to controls, while maintaining similar blood pressure control.
  • An earlier 2003 review of 57 studies had come up with similar results.

So we couldn’t really say with any certainty the effect cutting salt might or might not have on the development of high blood pressure—and we were even less sure of how reducing sodium in the diet would affect the risk of heart disease.

Could Reducing Salt INCREASE Risk of Heart Disease?

It’s one thing to wonder if cutting back on sodium does any good. It’s another to tell people to cut back when a low-sodium diet may cause harm.

In 2006, researchers looked at data from the second National Health and Nutrition Examination Survey (NHANES II) representing 78.9 million adults, ages 30-74. Over a period of 14 years, they observed the impact of sodium intake on cardiovascular disease and all-cause mortality, and found something surprising: those consuming more than 2,300 mg of sodium a day had a lower risk of heart disease and mortality than those who consumed less.

“The inverse association of sodium to CVD [cardiovascular disease] mortality seen here raises questions regarding the likelihood of a survival advantage accompanying a lower sodium diet,” the researchers wrote. “U.S. Dietary Guidelines recommend a daily sodium intake <2300 mg, but evidence linking sodium intake to mortality outcomes is scant and inconsistent.” In 2007, a similar study came out. Researchers followed participants 55 and older for five years, and found no consistent association between sodium intake and cardiovascular disease and all-cause mortality.

“The effect of sodium and potassium intake on CVD morbidity and mortality in Western societies remains to be established,” the researchers wrote.

Things have gotten even clearer over the last few years. In 2011, for example, researchers looked at data from about 3,600 participants without cardiovascular disease, followed up for about 8 years. Again, the results were a little startling: participants with the lowest intake of salt had the highest rate of death from heart disease. People who ate the most salt had the lowest rate of death from heart disease.

“Taken together,” the researchers wrote, “our current findings refute the estimates of computer models of lives saved and health care costs reduced with lower salt intake. They do also not support the current recommendations of a generalized and indiscriminate reduction of salt intake at the population level.” They added that the results did not, however, “negate the blood pressure-lowering effects of a dietary salt reduction in hypertensive patients.”

The Latest in a Line of Studies Raising Concerns About the Low-Salt Diet

Just a few months ago, a new study published in the Journal of the American Medical Association (JAMA) looked for any association between dietary sodium intake and mortality, heart disease, and heart failure in over 2,600 adults between the ages of 71 and 80, followed for 10 years. Results showed no association, no matter how much sodium the participants consumed.

Worse, some studies have shown that low-salt diets could have negative side effects:

  • Less than 3,000 may increase risk of death: A 2014 study that tracked 100,000 people from 17 countries for 3 years found that those who consumed less than 3,000 mg of sodium a day had a 27 percent higher risk of death or a serious event like a heart attack or stroke than those who consumed 3,000-6,000 g of sodium a day. This study didn’t show cause and effect, but it raised some concerns.
  • Low sodium linked with hospitalizations: A 2008 study found similar results—sodium depletion resulted in more health problems. Out of about 230 patients, those consuming low levels had more than three times the number of hospital admissions, and more than twice as many deaths as those in the higher-salt group.
  • Low sodium increases levels of triglycerides: Researchers note that too little sodium could trigger a hormonal response in the body that could actually increase blood pressure. Very low sodium is also associated with higher fat levels in the blood—another risk for heart disease. A 2012 study, for example, found that a low-salt diet increased levels of renin, aldosterone, adrenaline, cholesterol, and triglycerides in the blood—all shown to increase risk of heart disease. Low-sodium diets can also increase insulin resistance.
  • Low sodium linked with heart disease: A 2011 study looked at sodium and potassium intake and cardiovascular disease risk in about 29,000 patients, and found that those who excreted less than 3 grams per day had an increased risk of hospitalization and death from cardiovascular disease. (Those excreting more than 7 grams a day also had an increased risk.)
  • Low sodium diet risky for diabetics and the elderly: Some studies indicate that those with type 2 diabetes may be more vulnerable to a low-sodium diet. A 2011 study, for example, found that diabetes patients on a low-sodium diet had an increased risk of all-cause and cardiovascular mortality. Extremely low levels of sodium in the blood can also be dangerous in the elderly. A 2006 study found that it could increase risk of falls.
Some People are More Sensitive to Salt Than Others

Why were we seeing these results? Researchers remain unsure, but we do know that people are different, and that some respond to salt differently than others.

The kidneys are meant to help keep the electrolytes (including sodium) balanced in the body, and in most cases, they do a fine job at that. In some people, though, they may not be so efficient, and excess salt may cause unhealthy changes.

African Americans, for instance, are believed to be more sensitive to salt when it comes to high blood pressure. Studies have repeatedly noted a higher prevalence of high blood pressure in blacks than in whites—which is believed to cause the higher incidence of heart disease in blacks.

According to an editorial in a 2011 issue of Hypertension, African Americans retain more sodium in the kidneys than other races do. Even back in 1997, researchers reported: “Salt sensitivity is a heritable trait that is a hallmark of hypertension in black Americans.”

Scientists also theorize that age, overweight, and female gender may also make people more sensitive to salt and its potential effects on blood pressure.

What to Do?

With what we now know, what are we supposed to do about the salt in our diets? Is it okay to go hog wild and pour it on?

Most of the studies, including those listed above, show a danger in extremely high intakes, such as those over 6,000 mg. Estimates are that most Americans consume between 3,000 and 4,000 mg a day.

The American Heart Association recommends less than 1,500 mg a day.

The Department of Agriculture and the Department of Health and Human Services are said to be working on new dietary guidelines for sodium, to be issued this year (2015). Meanwhile, we can give you the following guidelines:

  1. Healthy adults probably don’t need to worry about salt intake. It is good to note that much of today’s dietary sodium comes from processed food, so eating a healthy diet is going to control salt intakes anyway.
  2. Sensitive populations, such as African Americans, those who are overweight, and those diagnosed with high blood pressure may want to just keep an eye on their blood pressure levels and their salt intake. Some people have found success in getting off blood pressure medications by cutting back on sodium intake, but it’s best to consider all potential lifestyle modifications, including increased exercise and intake of fruits and vegetables, realizing that sodium intake may or may not have any impact.
  3. All populations need to carefully consider any cutbacks in sodium. We have no concrete evidence that cutting back on salt will help you avoid heart disease or live longer. A better approach would be to rely on blood tests to be aware of your levels, and to observe levels of other nutrients as well, as it’s the interplay between them all that affects disease risk.

Bottom line: the human body is more complicated than we believed. As researchers noted in a 2000 study, “Not the sole and pervasive dietary villain it was once believed to be, sodium is but one factor in the complex interplay of multiple, inextricably related regulatory systems of which hypertension is the end result. With the data now available concerning dietary sodium…future public health recommendations can be based on carefully acquired, consistent, and rational science.”

What do you think of the salt/hypertension debate? Did you cut back on salt to reduce high blood pressure? If so, what were your results? Please share your thoughts.

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Sources
Melinda Wenner Moyer, “It’s Time to End the War on Salt,” Scientific American, July 8, 2011, http://www.scientificamerican.com/article/its-time-to-end-the-war-on-salt/.

Lewis K. Dahl, et al., “Influence of Dietary Potassium and Sodium/Potassium Molar Ratios on the Development of Salt Hypertension,” J Exp Med., August 1, 1972;136(2):318-330, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2139217/.

Gary Taubes, “Salt, We’ve Misjudged You,” New York Times, June 2, 2012, http://www.nytimes.com/2012/06/03/opinion/sunday/we-only-think-we-know-the-truth-about-salt.html?pagewanted=all.

Frank M. Sacks, et al., “Effects on Blood Pressure of Reduced Dietary Sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet,” New England Journal of Medicine, January 4, 2001; 344:3-10, http://www.nejm.org/doi/full/10.1056/NEJM200101043440101.

Cook NR, et al., “Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP),” BMJ, April 28, 2007; 334(7599):885-8, http://www.ncbi.nlm.nih.gov/pubmed/17449506.

“Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group,” BMJ, July 30, 1988; 297(6644):319-328, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1834069/.

Hooper L, et al., “Advice to reduce dietary salt for prevention of cardiovascular disease,” Cochrane Database Syst Rev, 2004;(1):CD003656, http://www.ncbi.nlm.nih.gov/pubmed/14974027.

Hooper L., et al., “Reduced dietary salt for prevention of cardiovascular disease,” Cochrane Database Syst Rev., 2003;(1):CD003656, http://www.ncbi.nlm.nih.gov/pubmed/12535482.

Cohen HW, et al., “Sodium intake and mortality in the NHANES II follow-up study,” Am J Med. March 2006; 119(3):275.e7-14, http://www.ncbi.nlm.nih.gov/pubmed/16490476.

Johanna M. Geleijnse, et al., “Sodium and potassium intake and risk of cardiovascular events and all-cause mortality: the Rotterdam Study,” Eur J Epidemiol. November 2007; 22(11):763-770, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2071962/.

Andreas P. Kalogeropoulos, et al., “Dietary Sodium Content, Mortality, and Risk for Cardiovascular Events in Older Adults: The Health, Aging, and Body Composition (Health ABC) Study,” JAMA Intern Med., January 19, 2015; doi:10.1001/jamainternmed.2014.6278, http://archinte.jamanetwork.com/article.aspx?articleid=2091399.

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Flavio D. Fuchs, “Why Do Black Americans Have Higher Prevalence of Hypertension?” Hypertension, 2011; 57:379-380, http://hyper.ahajournals.org/content/57/3/379.full.

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Ron Winslow, “Low-Salt Diets Masy Pose Health Risks, Study Finds,” Wall Street Journal, August 14, 2014, http://www.wsj.com/articles/recommended-salt-levels-could-do-more-harm-than-good-study-suggests-1407964274.

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Colleen M. Story

Colleen M. Story

Colleen M. Story, a northwest-based writer, editor, and ghostwriter, has been creating non-fiction materials for individuals, corporations, and commercial magazines for over 17 years. She specializes in the health and wellness field, where she writes and ghostwrites books, e-books, blogs, magazine articles, and more.

Colleen is the founder of Writing and Wellness. Her fantasy novel, “Rise of the Sidenah,” was released with Jupiter Gardens Press in September 2015. Her literary novel, “Loreena’s Gift,” is forthcoming in spring 2016 from Dzanc Books. She lives in Idaho. www.colleenmstory.com

4 COMMENTS ON THIS POST

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  1. Cliff says:

    Ther’s nothing in here about the difference between proper sea salt, iodised table salt, and normal table salt with added ingredients to make it pour better. I have always been under the impression that iodised salt was extremely beneficial, and that sea-salt was much healthier than normal table salt. It’s like all the other trials where so-called scientific experts use improper vitamins rather than natural to get the desired effect, which is that their drugs work and vitamins don’t. If any trial is set up without it being fully competent, how can any self-respecting person expect the results to be any good?

  2. Wendy says:

    I think it’s important to also add what kind of salt you are talking about. Processed table salt is obviously very different from pink salt or other healthy salts up that contain many minerals. Maybe you were assuming your readers know that, but many people don’t know the difference, so I just thought it should be mentioned.

  3. david says:

    What about the difference in salts? There is the chemical concoction found in the grocery stores and in processed foods, and there is the air-dried sea salt. These are as different as night and day, and the difference could account for much of the contradictory results from the different studies on salt. I doubt that 3 grams plus of air-dried sea salt per day would have much effect on blood pressure for most people and could even be beneficial in reducing blood pressure by providing many of the necessary trace minerals as well as providing the primary source of chlorine for the production of HCL which is absolutely necessary for digestion without which the body is unable to extract the necessary nutrients from our food.

  4. Sondra says:

    Actually, why do we need to put salt on our food anyway?
    Do not vegetables fruits etc. have enough natural sodium levels?
    Why is adding inorganic salt a requirement for health?

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