Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Our understanding of the way the body handles salt may be wrong

nytimes.com

Post reply on HN
Print view View original

21–30 of 88 posts

Re: Our understanding of the way the body handles salt may be wrong

#21

Post by closure »

dhimes wrote: post #17
cannonpr wrote: post #16

Earlier quoted context omitted.

That's interesting, did you control for changes in other diet elements, exercise, and water intake ? Some more recent studies show that except for short term spikes in blood pressure, salt isn't that guilty for high blood pressure in healthy individuals.

I'm going to throw a wrench into the gears by sharing the following: I had high blood pressure- not medication-triggering, just high-eyebrow stuff when I was younger (30s-early 40s). As a teenager I learned of the dangers of salt and weaned it out of my diet. I got married and am the cook of the family, so after much complaining I started to add salt to my dishes when I cooked. My blood pressure when down. Not by a l…

My cardiologist told me never to try a low-sodium diet without talking with him first. He is very up-to-date on research and said that an equal number of people see blood pressure increase on low-sodium as see blood pressure decrease but for many (most?) people the difference is negligible. In other words if you are one of the ones who is very sensitive to changes in sodium you are as likely to be harmed as helped by lowering sodium.

Re: Our understanding of the way the body handles salt may be wrong

#22

Post by PKop »

Swizec wrote: post #18
scandox wrote: post #7

This didn't surprise me so much. In several hot countries I have noted people taking salt to relieve thirst. In Mongolia I drank heavily salted tea (the usual there) all summer and it becomes quite natural. Maybe I'm missing some of the subtleties here?

You'll notice the same behavior from long distance runners, cyclists, hikers, etc. At some point you start feeling dehydration because you're missing electrolytes. If your water intake isn't salted or packed with minerals in some other way, it just makes you thirstier and thirstier. Especially when it's hot out.

This simple lesson was taught to us day one in boot camp when I was in the army, and reiterated constantly over the years.

We were required to take our salt packet out of our MRE's and eat the entire contents. The amount of water consumed (and flushed out through perspiration) throughout the day would have severely dehydrated anyone who didn't consume adequate (high) levels of salt.

Re: Our understanding of the way the body handles salt may be wrong

#23

Post by pilsetnieks »

abovemypaygrade wrote: post #13
reitanqild wrote: post #5

I think Thor Heyerdahl or someone on one of his crews noted that when they added seawater to the freshwater to make it last longer it also made them less thirsty. IIRC they thought it was an interesting observation since it was against all common understanding, but I don't think they ever came close to a solution to why.

Did he (or they) happen to mention the ratios of salt water to fresh? I don't know a whole lot about this topic, but I do recall reading somewhere that thirsty seafarers who succumbed to the urge to drink seawater ended up dying more quickly. I wonder if they figured out how much was okay to drink before it started negatively impacting health.

The negative impact is due to water loss via vomiting or diarrhea, and thus having a negative water balance. It's not like saltwater in itself kills you. In fact, you could drink the water of some less salty seas, e.g. the Baltic Sea.

Re: Our understanding of the way the body handles salt may be wrong

#24

Post by eropple »

Swizec wrote: post #18
scandox wrote: post #7

This didn't surprise me so much. In several hot countries I have noted people taking salt to relieve thirst. In Mongolia I drank heavily salted tea (the usual there) all summer and it becomes quite natural. Maybe I'm missing some of the subtleties here?

You'll notice the same behavior from long distance runners, cyclists, hikers, etc. At some point you start feeling dehydration because you're missing electrolytes. If your water intake isn't salted or packed with minerals in some other way, it just makes you thirstier and thirstier. Especially when it's hot out.

Goes back a lot longer than that, too. A large part of historical African trade was based around salt supplies.

Re: Our understanding of the way the body handles salt may be wrong

#25

Post by taneq »

closure wrote: post #21
dhimes wrote: post #17

Earlier quoted context omitted.

I'm going to throw a wrench into the gears by sharing the following: I had high blood pressure- not medication-triggering, just high-eyebrow stuff when I was younger (30s-early 40s). As a teenager I learned of the dangers of salt and weaned it out of my diet. I got married and am the cook of the family, so after much complaining I started to add salt to my dishes when I cooked. My blood pressure when down. Not by a l…

My cardiologist told me never to try a low-sodium diet without talking with him first. He is very up-to-date on research and said that an equal number of people see blood pressure increase on low-sodium as see blood pressure decrease but for many (most?) people the difference is negligible. In other words if you are one of the ones who is very sensitive to changes in sodium you are as likely to be harmed as helped by…

Wow, so the blanket "high blood pressure = eat less salt" advice given by most doctors sounds not just unhelpful but flat-out wrong and dangerous.

Re: Our understanding of the way the body handles salt may be wrong

#26

Post by tetraodonpuffer »

cannonpr wrote: post #16
tetraodonpuffer wrote: post #14

my n=1: I am on an extremely low sodium diet (around 500mg/day) and I didn't find any difference in thirst or hunger levels compared to when I was on a more typical 4000-5000mg/day one. The only change for me (besides of course a period of adjustment where food didn't taste like much) has been a significantly lower blood pressure (from typically 145/85 to 105/65), everything else has remained pretty much the same.

That's interesting, did you control for changes in other diet elements, exercise, and water intake ? Some more recent studies show that except for short term spikes in blood pressure, salt isn't that guilty for high blood pressure in healthy individuals.

no other changes, working out and water have been the same before and after (always worked out quite a bit, always drank quite a bit) same as appetite: I did not restrict sodium for blood pressure reasons, I was definitely surprised when I saw it that low and remain low since as all my life prior I've always been around the same higher but still normal bp, the sodium intake was the only change I made (of course this also implied some dietary changes, like no bread anymore due to sodium contents, but nothing else really major)

Would definitely be interested in finding more studies on extremely low sodium diets (especially on possible long term side effects), but finding information has been quite difficult.

Re: Our understanding of the way the body handles salt may be wrong

#27

Post by tetraodonpuffer »

Swizec wrote: post #18
scandox wrote: post #7

This didn't surprise me so much. In several hot countries I have noted people taking salt to relieve thirst. In Mongolia I drank heavily salted tea (the usual there) all summer and it becomes quite natural. Maybe I'm missing some of the subtleties here?

You'll notice the same behavior from long distance runners, cyclists, hikers, etc. At some point you start feeling dehydration because you're missing electrolytes. If your water intake isn't salted or packed with minerals in some other way, it just makes you thirstier and thirstier. Especially when it's hot out.

disagree, I went for a 5 hour fairly hard (~2000m of climbing) bike ride last summer in hot weather with no food and drinking only plain water (and not that much water at that, around 1l during the ride, of course I had a very large breakfast beforehand) without any issues whatsoever.

I am not sure about the whole "working out requires eating salt tabs", when I was doing triathlons a lot of people took them and it was amazing seeing all the salt that ended up on their clothing due to sweat/evaporation. I've always thought that if you really needed the electrolytes your body wouldn't immediately try to get rid of them via sweat.

Again of course this is n=1, I think maybe my n=1 is different because I am used to an extremely low sodium diet, but goes to show that when it comes to diet it's all a big YMMV...

Re: Our understanding of the way the body handles salt may be wrong

#28

Post by TheSpiceIsLife »

tetraodonpuffer wrote: post #26
cannonpr wrote: post #16

Earlier quoted context omitted.

That's interesting, did you control for changes in other diet elements, exercise, and water intake ? Some more recent studies show that except for short term spikes in blood pressure, salt isn't that guilty for high blood pressure in healthy individuals.

no other changes, working out and water have been the same before and after (always worked out quite a bit, always drank quite a bit) same as appetite: I did not restrict sodium for blood pressure reasons, I was definitely surprised when I saw it that low and remain low since as all my life prior I've always been around the same higher but still normal bp, the sodium intake was the only change I made (of course this…

It's not clear how you can say "no other changes" and follow on with "of course this also implied some dietary changes, like no bread anymore due to sodium contents".

That seems like a potentially significant change you're ignoring.

Re: Our understanding of the way the body handles salt may be wrong

#29

Post by tetraodonpuffer »

TheSpiceIsLife wrote: post #28
tetraodonpuffer wrote: post #26

Earlier quoted context omitted.

no other changes, working out and water have been the same before and after (always worked out quite a bit, always drank quite a bit) same as appetite: I did not restrict sodium for blood pressure reasons, I was definitely surprised when I saw it that low and remain low since as all my life prior I've always been around the same higher but still normal bp, the sodium intake was the only change I made (of course this…

It's not clear how you can say "no other changes" and follow on with " of course this also implied some dietary changes, like no bread anymore due to sodium contents ". That seems like a potentially significant change you're ignoring.

fair enough, although I personally don't think that cutting bread and eating more potatoes is that big of a difference overall, it is a difference so hey, for all I know that might have influenced things. As I was saying above, n=1 after all.

Re: Our understanding of the way the body handles salt may be wrong

#30

Post by runeks »

I have a hypothesis that all the negative effects associated with increased salt intake are really negative effects of overeating. If we measure the salt intake of people who primarily eat fast food -- which has a constant salt content -- the amount of salt ingested will be proportional to the amount of food ingested. So the person who eats five Big Mac meals a day will ingest, roughly, five times as much salt as a person eating only one, but I would claim the adverse effects associated with this are related to overeating, not the increased salt intake.

Is anyone familiar with studies that study the health effects of salt with this in mind? I.e. keeping food amounts constant over different groups, while varying only salt content?

Post reply on HN