More Dietary Salt Increases Urea Synthesis And Energy Requirements

Discussion in 'Scientific Studies' started by haidut, Apr 25, 2017.

  1. haidut

    haidut Member

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    The salt recommendations mentioned by Peat in some of his articles have been the source of much controversy. He has given accounts of people with various conditions recovering when they increased their salt intake to 1-2 tablespoons daily. I also posted studies showing that when sodium intake is below 5g (equivalent to about 1 tbsp salt) daily serotonin starts to rise and the renin-angiotensin system goes into overdrive, combined with increased catecholamines.
    It is considered "common knowledge" across the blogopshere and even mainstream medical practice that increased salt intake increases thirst, and consequently fluid intake, while at the same time reducing fluid excretion. It is the combination of increase fluid intake and decreased excretion that is given as explanation by doctors as to why eating more salt will increase blood pressure.
    This study decided to test the effects of various amounts of extra salt added to the diet of humans. The different amounts of extra salt tested were 6g, 9g, and 12g daily. What the study found was quite counterintuitive. Increasing salt intake led to decreased thirst and increased urine volume. Reducing salt intake generally had the opposite effects. What increased salt intake also did was increase urea synthesis and it was this increase in urea synthesis that allowed the kidneys to form urine saturated with sodium so that the extra sodium can get excreted. However, because synthesizing urea is such an energetically expensive process, increased salt intake indirectly increased energy requirements and thus made people hungrier as opposed to thirstier. Finally, the higher the salt intake, the lower the aldosterone release was in humans, exactly as Peat wrote. However, the higher the salt intake the higher the glucocorticoid release was in those same subjects. I think the increase in urea and energy requirements (metabolism) would be solid reasons to increase salt intake as per Peat's recommendations. However, the high cortisol release is potentially bothersome and may explain some negative effects of higher salt intake in sick people, as @burtlancast mentioned a few times.

    JCI - Increased salt consumption induces body water conservation and decreases fluid intake
    Mission Control for the body's salt and water supplies

    "...The results confirmed that eating more salt led to a higher salt content in urine - no surprise there. Nor was there any surprise in a correlation between amounts of salt and overall quantity of urine. But the increase wasn't due to more drinking - in fact, a salty diet caused the subjects to drink less. Salt was triggering a mechanism to conserve water in the kidneys. Before the study, the prevailing hypothesis had been that the charged sodium and chloride ions in salt grabbed onto water molecules and dragged them into the urine. The new results showed something different: salt stayed in the urine, while water moved back into the kidney and body. This was completely puzzling to Prof. Jens Titze, MD of the University of Erlangen and Vanderbilt University Medical Center and his colleagues. "What alternative driving force could make water move back?" Titze asked.

    "...Experiments in mice hinted that urea might be involved. This substance is formed in muscles and the liver as a way of shedding nitrogen. In mice, urea was accumulating in the kidney, where it counteracts the water-drawing force of sodium and chloride. But synthesizing urea takes a lot of energy, which explains why mice on a high-salt diet were eating more. Higher salt didn't increase their thirst, but it did make them hungrier. Also the human "cosmonauts" receiving a salty diet complained about being hungry. The project revises scientists' view of the function of urea in our bodies. "It's not solely a waste product, as has been assumed," Prof. Friedrich C. Luft, MD of the Charité and MDC says. "Instead, it turns out to be a very important osmolyte - a compound that binds to water and helps transport it. Its function is to keep water in when our bodies get rid of salt. Nature has apparently found a way to conserve water that would otherwise be carried away into the urine by salt."
     
  2. theLaw

    theLaw Member

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    @haidut

    In the Ray Peat Wiki (currently receiving an error message, so I can't find exact quote) he mentions that large doses of Salt can sometimes damage the stomach lining.

    Wonder if this is a situation (much like Aspirin) where it might need to be dissolved in liquid for easier digestion.

    Thoughts?

    Thanks!:D
     
  3. Giraffe

    Giraffe Member

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  4. theLaw

    theLaw Member

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    So is Ray using "appetite" in place of "taste" here, or does he mean something else?

    Thanks!:D
     
  5. charlie

    charlie The Law & Order Admin

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    Thank you for reporting, I will get that fixed up. :hattip
     
  6. Dante

    Dante Member

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    Just like calcium: phosphorus ratio and calcium:magnesium ration, is there such a thing called sodium : potassium ratio ? Will the requirements for potassium rise as one eats more salt ? ( I know its very reductionist but could the hunger be an increased need for K not for other macros/micros ) ?
     
  7. superhuman

    superhuman Member

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    Hmm. Interesting. I never really crave salt :( but i have symptoms that are associated with getting to little so its strange,
     
  8. OP
    haidut

    haidut Member

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    It's very difficult to have potassium deficiency as the body has strong affinity for it and absorbs it like crazy from every food that contains it, if the organism perceives a deficiency. Potassium and magnesium are intracellular minerals. Magnesium can be easily lost when ATP synthesis is low but potassium is not easily lost unless there is cell damage and then it spills in the blood. Even a suboptimal potassium intake does not tend to create deficiency as long as there is no tissue damage like over-exercising or severe hypothyroidism that can cause rhabdo. But trying to eat potassium rich foods like OJ, potatoes and even ripe/cooked bananas should address any deficiency concerns. I don't think there is a sodium : potassium ratio to be striving for.
     
  9. RMJ

    RMJ Member

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    if high salt increases the energy requirements

    could this lead to low blood sugar and consequently to higher cortisol?
     
  10. tankasnowgod

    tankasnowgod Member

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    I think Peat mentioned (in the KMUD interview) that Urea itself was a metabolic stimulant, and that urea applied to wounds could make them heal faster, and without scarring. It also works great as a skin moisturizer, if used topically.
     
  11. tankasnowgod

    tankasnowgod Member

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    I've heard anecdotal stories that people on low salt diets lose the taste for it, even if they are lacking it. You could try salt or electrolyte tablets, they are sold at places like Walgreens, Sporting Goods stores, and Amazon. Oddly, I never seen them at places like GNC or Vitamin Shoppe.
     
  12. jitsmonkey

    jitsmonkey Member

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    I cannot find my original source but I remember the issue with both aspirin and salt was in the form of a tablet/capsule.
    Dispersed as powder/granular was much less or not an issue
    Mixed with foods/liquids was a non issue
    I will keep looking for it.

    This is why the idea of salt tablets/capsules is no bueno
     
  13. OP
    haidut

    haidut Member

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    That's certainly a possibility. Another one is that aldosterone and cortisol may have an inverse relationship since they both bind to the same "receptors" and when aldosterone is lowered by the high salt then cortisol rises to compensate. But I like the energetic deficit explanation more.
     
  14. OP
    haidut

    haidut Member

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    That's true. Salt is also a direct metabolic stimulator itself. I think it increases the breakdown of ATP, which the cell takes as a message to produce a lot more as a response.
     
  15. Regina

    Regina Member

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    It sounds like pannacotta would be a great staple.
    Thanks for sharing this research.
     
  16. OP
    haidut

    haidut Member

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    Oh yeah! I eat it every time I go to an "Italian" restaurant around here. Even the fake ones have it on the menu. It probably has carageenan but I just don't care as it tastes so good.
     
  17. aguilaroja

    aguilaroja Member

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    I can “confirm” the anecdotes that some people accustomed to low salt diets or some with hypothyroid states lose appetite for salt. Other hypothyroid people crave salt and seem to partially self-treat by increasing salt intake.

    Habit seems to be part of it. In some cases, when the person is willing to increase salt intake, the appetite for salt also returns. Improvement of symptoms with adequate salt intake also reinforces the increased appetite for salt.
     
  18. Buteyko teacher

    Buteyko teacher Member

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    Does Peat distinguish different kinds of salt? Dr. Buteyko was big on unrefined (grey) sea salt. It contains 85 minerals in the same proportions found in the human body. He found that over-the-counter mineral supplements tend not to be absorbed by the body but minerals from sea salt do. Unrefined sea salt is also delicious. During my Buteyko teacher training we drank 'salt tea'. I thought it would be horrible. It was delicious. I encourage all my clients to throw out their table salt and get some of the good stuff.
     
  19. Tarmander

    Tarmander Member

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    I posted this is a different thread:
    I was curious what Peat thought and emailed him the study. He didn't have a ton to say:

    Me:
    I saw this study and wondered your opinion:

    JCI - Increased salt consumption induces body water conservation and decreases fluid intake

    They seem to be saying that increased salt intake would increase cortisol levels to break down fat and tissues for water, contrary to their belief that water intake was the main mechanism to maintain water balance.

    Would love to hear your opinion

    Peat:
    Thanks for the article link, it would be interesting to have more metabolic information about them during the salt changes.
     
  20. marikay

    marikay Member

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    Ray recommends clean white salt. No iodine. So the old fashioned table salt is fine as long as there is no iodine. Sea salt if it is white and non-iodized works well too.
     
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