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Across populations the average salt intake is around 3.7 grams of sodium per day. Sodium intake is actually regulated by the body, just like protein. Your body

Across populations the average salt intake is around 3.7 grams of sodium per day. Sodium intake is actually regulated by the body, just like protein. Your body demands more salt when it needs it. Which means that around 3.7 grams might actually be the optimal amount of sodium intake. There are many studies showing that the standard recommendation for reducing the salt intake is bullshit. Not only that, but reduced salt intake is linked to obesity and sugar cravings. Also before refrigerators, like in the 19th century, people consumed a lot more sodium because salt was the primary way to preserve food, especially meat. All modern chronic diseases were rare back then ... and yes, heart disease was harder to diagnose, but improvements in technology can't explain it fully, plus we are also talking of diabetes and cancer. For skeptics, I recommend reading "The Salt Fix" which provides a good overview of the history and of various studies: http://thesaltfix.com/ http://thesaltfix.com/ --- I'm not saying that healthcare professionals are idiots. The problem is that healthcare is reductionist. Studies that properly use the scientific method don't lie, but the problem is that people often reach the wrong conclusions. It's like in that fable in which a group of blind people are told to feel and describe an elephant, only in real life some of the blind people have more political clout than others.

pjc50 8y ago
I have been wondering about this. Does anybody know what the original "salt leads to hypertension" paper was?
- glastra 8y ago
  Maybe someone thought about it mechanistically in the sense that more sodium in our blood also means more water (to keep both electrolyte balance and dilution in acceptable ranges to sustain life). More water means more blood volume or pressure if volume is limited. Someone then probably tried to prove this by checking whether dietary salt intake leads to hypertension. However, medical and nutritional science are very limited in the ways they can conduct research. So they probably did an epidemiological study and saw that populations with hypertension also had a high dietary salt intake. Proof! Except... well, no. Our kidneys are perfectly capable of balancing this out as long as we don't ask too much of them. More salt in your food than you need? More sodium in your pee. Less salt in your food than you need? Well, you're screwed. Edit: Sorry for being unable to provide a direct answer to your question, but I felt compelled to reply. Edit 2: After a search in Google Scholar, the earliest study I could find is from 1950 [0]. They studied the link between salt and hypertension in rats by replacing their drinking water with 2% salt solutions and measuring their blood pressure. It seems to me that all non-epidemiological studies are useless extremes... With no "clean" water (all water intake was hypertonic) the kidneys can't really dispose of much. [0]: http://sci-hub.tw/https://journals.sagepub.com/doi/abs/10.3181/00379727-73-17583 http://sci-hub.tw/https://journals.sagepub.com/doi/abs/10.31... Edit 3: The actual paper recognises in the discussion (with citations) that it is impossible to cause hypertension in rats without artificially controlling all their water intake. Wow. Even if all water is salted, as long as it's iso- or hypotonic there is no hypertension.
- gerbilly 8y ago
  I read long ago that a famous american cardiologist simply asserted that high salt intake leads to high blood pressure, and that it has been known as a fact since then. Regrettably I can't find the source.
  - bad_user 8y ago
    There have been studies showing that, but they've been inconclusive according to the meta reviews. It's like with cholesterol, i.e. the claim that eating saturated fat can increase LDL particles in your bloodstream (it can), but to jump from there to claiming that increased LDL causes heart disease is a stretch, because LDL is just a transport mechanism and naturally, it depends on what it transports. People are inclined to search for easy solutions. But unfortunately nothing is easy about our metabolism.
    - gerbilly 8y ago
      There have also been studies showing no meaningful long term association between salt intake and high blood pressure as well. The stories that get retold, aren't the ones that are true, but often the ones that are simplest to tell.
- ssvss 8y ago
  Just an anecdote, from my experience of water-only intermittent fasting for 5 days. First time I did it, from around day 3, I will start feeling dizzy, if I suddenly standup from either lying down or sitting in a relaxed posture. Later I read that it was caused because of low blood pressure due to no salt intake. The next time I did intermittent fasting, I took some salt with my water, and the dizziness problem was not there.

pjc50 8y ago

I have been wondering about this. Does anybody know what the original "salt leads to hypertension" paper was?

glastra 8y ago
Maybe someone thought about it mechanistically in the sense that more sodium in our blood also means more water (to keep both electrolyte balance and dilution in acceptable ranges to sustain life). More water means more blood volume or pressure if volume is limited. Someone then probably tried to prove this by checking whether dietary salt intake leads to hypertension. However, medical and nutritional science are very limited in the ways they can conduct research. So they probably did an epidemiological study and saw that populations with hypertension also had a high dietary salt intake. Proof! Except... well, no. Our kidneys are perfectly capable of balancing this out as long as we don't ask too much of them. More salt in your food than you need? More sodium in your pee. Less salt in your food than you need? Well, you're screwed. Edit: Sorry for being unable to provide a direct answer to your question, but I felt compelled to reply. Edit 2: After a search in Google Scholar, the earliest study I could find is from 1950 [0]. They studied the link between salt and hypertension in rats by replacing their drinking water with 2% salt solutions and measuring their blood pressure. It seems to me that all non-epidemiological studies are useless extremes... With no "clean" water (all water intake was hypertonic) the kidneys can't really dispose of much. [0]: http://sci-hub.tw/https://journals.sagepub.com/doi/abs/10.3181/00379727-73-17583 http://sci-hub.tw/https://journals.sagepub.com/doi/abs/10.31... Edit 3: The actual paper recognises in the discussion (with citations) that it is impossible to cause hypertension in rats without artificially controlling all their water intake. Wow. Even if all water is salted, as long as it's iso- or hypotonic there is no hypertension.
gerbilly 8y ago
I read long ago that a famous american cardiologist simply asserted that high salt intake leads to high blood pressure, and that it has been known as a fact since then. Regrettably I can't find the source.
- bad_user 8y ago
  There have been studies showing that, but they've been inconclusive according to the meta reviews. It's like with cholesterol, i.e. the claim that eating saturated fat can increase LDL particles in your bloodstream (it can), but to jump from there to claiming that increased LDL causes heart disease is a stretch, because LDL is just a transport mechanism and naturally, it depends on what it transports. People are inclined to search for easy solutions. But unfortunately nothing is easy about our metabolism.
  - gerbilly 8y ago
    There have also been studies showing no meaningful long term association between salt intake and high blood pressure as well. The stories that get retold, aren't the ones that are true, but often the ones that are simplest to tell.
ssvss 8y ago
Just an anecdote, from my experience of water-only intermittent fasting for 5 days. First time I did it, from around day 3, I will start feeling dizzy, if I suddenly standup from either lying down or sitting in a relaxed posture. Later I read that it was caused because of low blood pressure due to no salt intake. The next time I did intermittent fasting, I took some salt with my water, and the dizziness problem was not there.