Pass the salt please?

One of the great “truths” in cardiovascular medicine is that to prevent stroke and cardiovascular death you reduce your salt intake. But is it true? A new analysis of the existing literature from the Cochrane Library indicates this may not be the case (1). Analyzing a great number of published studies, researchers came to the conclusion that there is no strong evidence to support the idea that salt restriction reduces cardiovascular disease or all-cause mortality in people with either normal or increased blood pressure. Furthermore, they found that while reducing salt intake did decrease blood pressure, it also increased the risk of all-cause death in people with existing congestive heart failure.

If that wasn’t enough, an article in the May 4 issue of the Journal of the American Heart Association found that low salt increased the risk of death from heart attacks and stokes, while not reducing blood pressure (2). This study was done with middle-aged Europeans and followed them for nearly eight years. During this time, the less salt they consumed, the greater the number who died of heart disease.

Needless to say, the American Heart Association (the same people who recommend eating lots of omega-6 fats) was enraged, similar to the Wizard of Oz telling Dorothy to ignore the man behind the curtain.

So why might restriction of salt consumption cause increased heart attacks? The reason may be due to increased insulin resistance induced by salt restriction (3). Insulin resistance increases insulin levels, and if that is combined with increased consumption of omega-6 fatty acids (remember the American Heart Association), you now have a sure-fire prescription to produce more arachidonic acid. It’s the inflammatory eicosanoids derived from arachidionic acid that would cause inflammation in the arterial wall leading to a heart attack.

This is not to say that some people are not salt-sensitive (African-Americans are particularly so), but I believe the problem is more a matter of balance. You need some sodium, but you also need potassium to balance it. This is confirmed by a recent study from Harvard Medical School that demonstrates that the higher the sodium-to-potassium ratio in the blood, the greater the likelihood of cardiovascular mortality (4). The relationship for increased death was significantly greater for a high sodium-to-potassium level than simply the sodium level itself.

Getting sodium in your diet is easy (sprinkle salt on your food), but getting adequate levels of potassium means eating a lot of fruits and vegetables. So rather than restricting salt intake or taking drugs (i.e. diuretics) to reduce the levels of sodium in the body, think about eating more fruits and vegetables if your goal is to reduce the likelihood of a heart attack. Oh, yes, also ignore the advice of American Heart Association and take more omega-3 and less omega-6 fatty acids.

References

  1. Taylor, RS, Ashton KE, Moxham T, Hooper L and Ebrahim S. “Reduced dietary salt for the prevention of cardiovascular disease.” Cochrane Database of Systematic Reviews DOI: 10.1002/14651858.CD009217 (2011)
  2. Stolarz-Skrzypek K, Kuznetsova T, Thijs L, Tikhonoff V, Seidlerova J, Richart T, Jin Y, Olszanecka A, Malyutina S, Casiglia E, Filipovsky J, Kawecka-Jaszcz K, Nikitin Y, and Staessen JA. “Fatal and nonfatal outcomes, incidence of hypertension, and blood pressure changes in relation to urinary sodium excretion.” JAMA 305: 1777-1785 (2011)
  3. Alderman MH. “Evidence relating dietary sodium to cardiovascular disease.” J Am Coll Nutr 25: 256S-261S (2006)
  4. Yang Q, Liu T, Kuklina EV, Flanders WD, Hong Y, Gillespie C, Chang M-H, Gwinn M, Dowling N, Khoury MJ, and Hu FB. “Sodium and potassium intake and morality among US adults.” Arch Intern Med 171: 1183-1191 (2011)

Nothing contained in this blog is intended to be instructional for medial diagnosis or treatment. If you have a medical concern or issue, please consult your personal physician immediately.

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This entry was posted in Zone Health and tagged , , , , by Dr. Barry Sears. Bookmark the permalink.

About Dr. Barry Sears

Dr. Barry Sears is a leading authority on the impact of the diet on hormonal response, genetic expression, and inflammation. A former research scientist at the Boston University School of Medicine and the Massachusetts Institute of Technology, Dr. Sears has dedicated his research efforts over the past 30 years to the study of lipids. He has published more than 30 scientific articles and holds 13 U.S. patents in the areas of intravenous drug delivery systems and hormonal regulation for the treatment of cardiovascular disease. He has also written 13 books, including the New York Times #1 best-seller "The Zone". These books have sold more than 5 million copies in the U.S. and have been translated into 22 different languages.

25 thoughts on “Pass the salt please?

  1. More advice from the AHA to be taken with a grain of salt!(Sorry, couldn’t resist). i might add to use a good sea salt, rather than pure sodium chloride.

  2. Hi Dr. Sears,

    I’m a big fan of your work, and follow a diet similar to the ZONE myself. I take your fish oil product every day, and enjoy your low-GI cereal and pastas.

    But the data from the Harvard Nurse’s Study and the Harvard Physician’s Study seems to support the conjecture that increasing omega 6 reduces heart disease risk?

    It seems to me that there is an “omega 6 paradox” here: The omega 6 are pro-inflammatory through the arachadonic acid (AA) pathway (which is obviously a bad thing as you point out), but somehow these cohort studies keep showing that omega 6 reduces heart disease risk. A paradox, it seems?

    Could you comment on this “omega6 paradox” ?

    When Walter Willett was asked a similar question, he agreed that omega-6 can be pro-inflammatory through AA, but argued that the omega-6 are anti-inflammatory through the NF-kappa-B and PPAR-gamma pathways, and that they lower LDL cholesterol. He claims that this is why they reduce heart disease (and diabetes) risk. Can you give us your opinion on this?

    Thanks very much,
    Louis

    • It is not omega-6 fatty acids per se, but only when they are further transformed into arachidonic acid (AA) coupled with a corresponding decrease in EPA. This is why the JELIS intervention study with some 18,000 patients getting statins demonstrated that lowering the AA/EPA to under 1 further reduced cardiovascular events by an additional 20%. Epidemiological studies such as those done by Willett only address associations, not causality. This is why intervention studies are required to either support or deny the association.

      Furthermore, it is different eicosanoids such as leukotrienes derived from AA that affect NF-kappaB and whereas other eicosanoids derived from AA affect PPAR-gamma. However EPA is much more powerful activator of PPAR-gamma than the eicosanoids derived from AA.

      Bottom line, always trust very large intervention studies (like JELIS) in humans to give a better insight into how to develop an anti-inflammatory diet. This means reduce AA and increase EPA and measure your successful the AA/EPA ratio in the blood.

  3. I would hazard a guess they lower LDL because more cholesterol is needed to stiffen up cell walls softened by so much pufa, hence not so much being broken down and sent for reuse.

  4. Hi Dr. Sears,

    Sometimes I cannot believe the information you read. It is hard for us who are not as medically knowledgeable as others. Heart attacks and strokes are a big issue for me so an understanding of information is important. There must be a point when you take in too much salt. So what would that be? I am always low on potassium levels too. Even though I constantly eat fruits and vegetables it isn’t ever enough. I really wish you would develop a pill that we could take for each meal. It would help a lot!!!

  5. Omega-6 fats actually lower LDL cholesterol levels since less cholesterol is required to maintain LDL particle fluidity if there were replaced by saturated fats. However, the role of LDL particles is to deliver lipids to the peripheral tissue. So if you decrease LDL cholesterol levels, but deliver more omega-6 fatty acids to the tissues (like the arterial walls of blood vessels) you are doing more long-term harm than good. Keep in mind it is not omega-6 fats per se that are inflammatory, only when they are transformed into arachidonic acid that the inflammatory ball starts rolling. That transformation process is accelerated by elevated insulin levels.

    • And where does the elevated insulin levels begin? With the excessive consumption of glucose-rich foods and/or, in the case of an overweight type 2 diabetic, oral sulfonylureas and exogenous insulin.

  6. I´ve just remembered that Dr. Robert Galambos in his book Nerves and Muscles explains why sodium and potassium have to be in a good balance in order to produce the necessary electric voltages that make our body muscles (including our heart muscles) work properly.

  7. High blood pressure is easily reduced by the addition of sufficient Garlic to your diet. My doctor, Gene Denk, had me take 3 Kyolic (Oderless Garlic) tablets daily. With in 2 weeks my blood presure had dropped from 180/100 to 70/50. I had been on a low salt diet.
    When I called him, he recommended that I go back to my previous salt usage and continue the Garlic.
    The result has been 15 years with blood pressure 130/70, and NO DRUGS.

  8. I have been trying to follow your diet recommendations in combination with a high K factor (ratio of potassium to sodium) diet for several years. Would it be possible to develop some of your products (zone meals, etc.) that also had a high K factor? I know I would greatly appreciate such products. Maybe others would too.

  9. Dr Sears:
    What about Potassium Chloride products on the market that are presented as “salt substitutes” for Sodium Chloride salt? Are these a good and helpful regarding maintaining a healthy balance?

  10. The latest findings have been an ongoing news item since the beginning of time.
    Yesterday the the latest findings said the opposite o the latest findings of today and
    I expect the latest findings to change again tomorrow.
    The latets findings is nonsense.
    How old is the icon picture of Dr. Sears? Why doesn’t he change it to a picture of himself
    as he looks today and not an old picture of yesteryear?

    • Dr. Sears,
      In a recent post you said that you would not be able to asses the quality of the Omega RX 3 by Natural Factors, endorsed by Dr. Murray, EPA 400, DHA 200, without knowing the TOTOX and PCB levels. I wrote the company requesting the information and they responded with the below. Please look it over and respond with your assessment of the product based on what’s given.
      Dear Joe,

      Thank you for your inquiry regarding Natural Factors Rx-Omega 3 Factors products; we appreciate you taking the time to contact us.

      Below is an outline of our processing steps and material tests. Natural Factors does not use solvents during any stage of manufacturing. Salmon oils are sourced from the flesh, not the liver so are not processed using molecular distillation because they do not require extra purification or concentration:

      – Identity of medicinal ingredient(s)

      – Purity (microbial)

      – total aerobic count, yeast & mold, E. coli, salmonella & staphylococcus aureus

      – Purity (chemical)

      – arsenic, cadmium, lead & total mercury

      – pesticides – tested on raw material only

      – specific contaminants [Dioxins (PCDDs, PCDFs) & PCBs] – tested on raw material only

      – peroxide value

      – solvent residues (if applicable)

      – Quantity/Potency

      We guarantee our fish oil products to meet the following acceptance levels:

      Pesticides – Less than 1 ppm

      PCB’s (Polychlorinated Biphenyls) – Less than 1 ppm

      Dioxins – Less than 2 pg TEQ/g

      Note on units – Dioxins are expressed in the World Health Organization (WHO) unit of Toxic Equivalents (TEQ). ppm = parts per million.

      As part of our commitment to ensuring the safety and quality of our products, Natural Factors has implemented a tighter control over the testing of our fish oils. Under the Health Products and Foods Branch of Health Canada, the Natural Health Products (NHP) regulations came into effect January 1, 2004. In order to comply with the Natural Health Products Directorates (NHPD) acceptance limits for chemical contaminants, we have been revising our test specifications to the following limits:

      Contaminant NHPD Limit

      Arsenic <0.14 mcg/kg b.w./day

      Cadmium <0.09 mcg/kg b.w./day

      Lead <0.29 mcg/kg b.w./day

      Mercury <0.29 mcg/kg b.w./day

      PCBs <0.09 mcg/kg b.w./day

      Dioxins <2 pg/kg b.w./day

      kg = kilograms
      g = grams
      mcg = microgram
      pg = picogram
      b.w. = body weight

      Note that the limits are dependant on body weight. This means that for children's products, we apply a lower tolerance level for heavy metals, PCBs and dioxins.

      Molecular distillation is used to remove toxins from the liver oils of bottom feeding fish where there is more risk to the fish exposed to such things as mercury poisoning and other toxins that accumulate in the liver. Natural Factors Cod liver oil and Halibut liver oil are molecularly distilled as are the fish oils in the RxOmega-3 Factors products which are concentrated and refined using this process. After many steps of distillation, filtrations and deodorization, Natural Factors customers can be assured that this high-quality product is free of contaminants. In general, the crude fish oil is physically refined (degumming and neutralizing) then filtered and deodorized. After this process the oil is tested.

      Molecular distillation is a process for purifying heat-sensitive liquids (e.g. fish oils) using a vacuum or low pressure still. Distillation is a method of separating chemical substances based on differences in their tendency to vaporize (volatility) in a boiling liquid mixture – the chemical impurities have a different volatility than the fish oil and can therefore be separated out. Under a vacuum or low pressure approaching a vacuum, the temperature at which a liquid boils is significantly lower than at regular atmospheric temperature. Therefore, at low pressure, a fragile fish oil can be purified without destroying the active ingredients.

      We hope this information is helpful and you continue to find Natural Factors to be your quality product of choice.

      Sincerely,

      Vivian Hsieh, BSc FNH
      Natural Factors
      1550 United Boulevard
      Coquitlam BC V3K 6Y7
      T: 1-800-663-8900/604.777.3725
      F: 1-800-663-2115/604.777.4777

      • Those levels of PCBs are not too assuring at less than 1 ppm. This corresponds to 1000 ppb. OmegaRx standard for PCBs is currently less than 5 ppb. The state of California has law that any 1 gram capsule of fish oil that contains more 90 ppb of PCBs cannot be sold because of toxicity. This is why the purity of a fish oil can be strongly correlated with the levels of PCBs in that fish oil.

      • Perhaps Jockobono is not happy with aging…however it sure beats the alternative…your picture is great…I saw you give a talk 20 years ago and you’re aging well

    • Hi Jockobono
      The latest findings in the research of the mechanism of action of sodium and potassium levels in the viability of cells gives more definite information to researchers in how cells transport compounds in and out. The electrical balance is vital to staying alive. We have known for many years that both sodium and potassium levels are important to watch. Now scientists are able to monitor systems at a cellular level. The technology is amazing. Now, if you have a car, wouldn’t you want to be sure the battery is properly charged so your car will start? Same thing goes for your heart. The right amount of positive and negative ions in the battery will start your car. The right amount of positive and negative ions in your body lets you wake up every morning. Stay healthy.

  11. Hi, Dr. Sears,
    A couple of questions: I’d heard that Zone Labs was going to get the blood SIP test. Any progress? What do you take for supplements on a daily basis? Is a baby aspirin part of your regime?
    Thanks,
    Joe

  12. It sure proves the legitimacy of The Zone and Dr. Sears when opinions that factually discredit the Zone and Dr. Sears are deleted and censored . Thank you, Dr. Sears, for being the chief of such a disrespectful and corrupted organization which hides any posted facts.

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