5 ms·

The Reassuring Science of Salt Consumption

48 points by tokenadult 10y ago

jimrandomh 10y ago
The entire field of research around salt is a colossal fuckup, for a fairly simple reason: sweat is salty. If you sweat, due to exercise or high temperatures, you lose about 1g/L of sodium. So right off the bat, all the research that's trying to find a population-wide correct amount of sodium to eat is on a wrong track, because there's no such thing. But it's even worse, because most of the research doesn't measure the amount of sodium people take in through food, it measures the amount of sodium they lose in urine. This isn't their intake, it's what's left after losses, so it's confounded by exercise. And it's even worse than that, because while the actual studies indicate that there's no benefit from cutting salt intake, some high-status organizations once said there was, and are acting as though they can't take it back without losing face. The overall result is that there are a bunch of people shouting "less salt!" and a bunch of people shouting "the same amount of salt!" and no one has any model of how much salt they actually need, so they occasionally end up deficient.
- kevin_thibedeau 10y ago
  It goes beyond behavioral differences. All complex life forms use sodium channels to regulate basic cellular activity. Consequently we all have a nephritic system that regulates sodium levels as a requirement for living. Too much sodium is literally pissed away. The anti-salt crowd conveniently glosses over this.
- tcj_phx 10y ago
  > The overall result is that there are a bunch of people shouting "less salt!" and a bunch of people shouting "the same amount of salt!" and no one has any model of how much salt they actually need, so they occasionally end up deficient. Dr. Brewer's pregnancy diet calls for as much salt as the patient wants - "salt to taste". One of the things I had to help my girlfriend with was getting her over her salt phobia - she definitely wasn't getting enough. There is a disconnect between medical science and the actual findings of physiology. Medical students are indoctrinated with lots of facts and a little dogma. The incorrect ideas stunts the progress of their field. Veterinarians know to give animals as much salt as they want.
  - homero 10y ago
    Humans need salt licks
kirrent 10y ago
I always find it fascinating how much nutrition as a science is clearly in its infancy. It's true that rigorous science in medicine is relatively recent compared to other fields of study but in nutrition we're still seeing major changes to the consensus and guidelines. My favourite example is probably cholesterol. Nearly everyone instinctively knows that eating too much cholesterol will raise your cholesterol levels and puts you at risk of heart disease. Don't eat too many eggs or you'll go to an early death. The thing is, that view, which has been informed from the advice from authorities over the past few decades, is completely wrong. As the panel determining the Dietary Guidelines for Americans concluded in 2014 - "Cholesterol is not considered a nutrient of concern for overconsumption," and as a result, warnings about cholesterol has since been removed from the guidelines. Obviously the link between dietary and blood cholesterol is more complex than initially thought but it's still staggering to me that such a simple recommendation could have been so wrong and how government guidelines can lag the scientific consensus. It's interesting to see that much the same can be applied to salt and the solution is the same. Eat a variety of food and try to avoid as much processed food as possible.
- tcj_phx 10y ago
  > Eat a variety of food and try to avoid as much processed food as possible. "Vegetable oil" is the most processed of all food ingredients. Almost all cheap vegetable oils are extracted with solvents (Hexane) and steam-treated to remove odors and lighten the color. The only appropriate use for these oils is as biodiesel. Coconut oil can be refined to safely remove odors without causing the oil itself to go rancid. [1] [1] https://www.mountainroseherbs.com/products/coconut-oil-refined/profile https://www.mountainroseherbs.com/products/coconut-oil-refin...
  - gruez 10y ago
    Hexane is used as the solvent and it's evaporated away after oil extraction, leaving behind oil. What's the issue here?
- stephendedalus 10y ago
  Truly in its infancy. The phrase I always use when in a grocery store is whether I'm purchasing things that are "recognizably food". Vegetables, fruits, meat all remind you of their original source or are identical to the original thing. Where food rates on this "eye test" degrades considerably as you move into more and more processed food. It's one of those things that feels common sense and the further along we get the more it appears that it's true. That eating an egg is worse for you than fat-free protein bars seems preposterous now, but there was a time when that was the orthodoxy.
mrfusion 10y ago
I always wonder why things that taste salty don't seem to have that much sodium. I was eating a bag of salt and vinager chips and could just taste all the salt. I figured I'd be getting 150% of my dv of sodium but no only 9%.
- grogenaut 10y ago
  I couldn't find it wth a quick search but I remember an article about how the food industry was voluntarily reducing the amount of salt in things. One interesting part was reddenbocker lowering salt in popcorn. They did this by realizing that it was actually the amount of surface area of salt on your tongue not the mass of the salt that mattered. They had therefore gone to ultra-fine ground salt and had reduced the total salt content of their popcorn by like 70%. Wish I could find it but there were some interesting things by googing "food industry salt reduction".
  - JoeAltmaier 10y ago
    Similarly the orange dust on highly-flavored snack chips is superfine, to give an extreme blast of flavor for very little ingredient investment.
    - grogenaut 10y ago
      Also for maximum finger pore saturation!
      - JoeAltmaier 10y ago
        One day we'll learn it is a health hazard, like talcum powder.
jrapdx3 10y ago
One thing easily overlooked is that recommendations for sodium intake depend on individual considerations. Sodium restriction may be important in conditions other than hypertension. For example, people who excrete too much urinary calcium are at risk of kidney stones and bone loss. Reducing salt consumption is usually necessary to decrease calcium depletion and prevent bad outcomes. As I've observed it, the chances of people getting too much dietary sodium far exceeds getting too little. The FDA's idea to reduce sodium content of foods is most likely a constructive step forward.

48 points by tokenadult 10y ago

The entire field of research around salt is a colossal fuckup, for a fairly simple reason: sweat is salty. If you sweat, due to exercise or high temperatures, you lose about 1g/L of sodium. So right off the bat, all the research that's trying to find a population-wide correct amount of sodium to eat is on a wrong track, because there's no such thing. But it's even worse, because most of the research doesn't measure the amount of sodium people take in through food, it measures the amount of sodium they lose in urine. This isn't their intake, it's what's left after losses, so it's confounded by exercise. And it's even worse than that, because while the actual studies indicate that there's no benefit from cutting salt intake, some high-status organizations once said there was, and are acting as though they can't take it back without losing face. The overall result is that there are a bunch of people shouting "less salt!" and a bunch of people shouting "the same amount of salt!" and no one has any model of how much salt they actually need, so they occasionally end up deficient.

kevin_thibedeau 10y ago
It goes beyond behavioral differences. All complex life forms use sodium channels to regulate basic cellular activity. Consequently we all have a nephritic system that regulates sodium levels as a requirement for living. Too much sodium is literally pissed away. The anti-salt crowd conveniently glosses over this.
tcj_phx 10y ago
> The overall result is that there are a bunch of people shouting "less salt!" and a bunch of people shouting "the same amount of salt!" and no one has any model of how much salt they actually need, so they occasionally end up deficient. Dr. Brewer's pregnancy diet calls for as much salt as the patient wants - "salt to taste". One of the things I had to help my girlfriend with was getting her over her salt phobia - she definitely wasn't getting enough. There is a disconnect between medical science and the actual findings of physiology. Medical students are indoctrinated with lots of facts and a little dogma. The incorrect ideas stunts the progress of their field. Veterinarians know to give animals as much salt as they want.
- homero 10y ago
  Humans need salt licks

kirrent 10y ago

I always find it fascinating how much nutrition as a science is clearly in its infancy. It's true that rigorous science in medicine is relatively recent compared to other fields of study but in nutrition we're still seeing major changes to the consensus and guidelines. My favourite example is probably cholesterol. Nearly everyone instinctively knows that eating too much cholesterol will raise your cholesterol levels and puts you at risk of heart disease. Don't eat too many eggs or you'll go to an early death. The thing is, that view, which has been informed from the advice from authorities over the past few decades, is completely wrong. As the panel determining the Dietary Guidelines for Americans concluded in 2014 - "Cholesterol is not considered a nutrient of concern for overconsumption," and as a result, warnings about cholesterol has since been removed from the guidelines. Obviously the link between dietary and blood cholesterol is more complex than initially thought but it's still staggering to me that such a simple recommendation could have been so wrong and how government guidelines can lag the scientific consensus. It's interesting to see that much the same can be applied to salt and the solution is the same. Eat a variety of food and try to avoid as much processed food as possible.

tcj_phx 10y ago
> Eat a variety of food and try to avoid as much processed food as possible. "Vegetable oil" is the most processed of all food ingredients. Almost all cheap vegetable oils are extracted with solvents (Hexane) and steam-treated to remove odors and lighten the color. The only appropriate use for these oils is as biodiesel. Coconut oil can be refined to safely remove odors without causing the oil itself to go rancid. [1] [1] https://www.mountainroseherbs.com/products/coconut-oil-refined/profile https://www.mountainroseherbs.com/products/coconut-oil-refin...
- gruez 10y ago
  Hexane is used as the solvent and it's evaporated away after oil extraction, leaving behind oil. What's the issue here?
stephendedalus 10y ago
Truly in its infancy. The phrase I always use when in a grocery store is whether I'm purchasing things that are "recognizably food". Vegetables, fruits, meat all remind you of their original source or are identical to the original thing. Where food rates on this "eye test" degrades considerably as you move into more and more processed food. It's one of those things that feels common sense and the further along we get the more it appears that it's true. That eating an egg is worse for you than fat-free protein bars seems preposterous now, but there was a time when that was the orthodoxy.

mrfusion 10y ago

I always wonder why things that taste salty don't seem to have that much sodium. I was eating a bag of salt and vinager chips and could just taste all the salt. I figured I'd be getting 150% of my dv of sodium but no only 9%.

grogenaut 10y ago
I couldn't find it wth a quick search but I remember an article about how the food industry was voluntarily reducing the amount of salt in things. One interesting part was reddenbocker lowering salt in popcorn. They did this by realizing that it was actually the amount of surface area of salt on your tongue not the mass of the salt that mattered. They had therefore gone to ultra-fine ground salt and had reduced the total salt content of their popcorn by like 70%. Wish I could find it but there were some interesting things by googing "food industry salt reduction".
- JoeAltmaier 10y ago
  Similarly the orange dust on highly-flavored snack chips is superfine, to give an extreme blast of flavor for very little ingredient investment.
  - grogenaut 10y ago
    Also for maximum finger pore saturation!
    - JoeAltmaier 10y ago
      One day we'll learn it is a health hazard, like talcum powder.

jrapdx3 10y ago

One thing easily overlooked is that recommendations for sodium intake depend on individual considerations. Sodium restriction may be important in conditions other than hypertension. For example, people who excrete too much urinary calcium are at risk of kidney stones and bone loss. Reducing salt consumption is usually necessary to decrease calcium depletion and prevent bad outcomes. As I've observed it, the chances of people getting too much dietary sodium far exceeds getting too little. The FDA's idea to reduce sodium content of foods is most likely a constructive step forward.