
Our understanding of the way the body handles salt may be wrong - mherrmann
https://www.nytimes.com/2017/05/08/health/salt-health-effects.html?mc=adintl&mcid=keywee&subid=pay&subid1=nordicEU&ad-keywords=auddevgate&kwp_0=413855&kwp_4=1523157&kwp_1=662103
======
dottrap
This needs to be paired with Scientific American: It's time to end the war on
salt

[https://www.scientificamerican.com/article/its-time-to-
end-t...](https://www.scientificamerican.com/article/its-time-to-end-the-war-
on-salt/)

~~~
SepUltra
Actually, the Scientific American article is wrong. This space study also
concludes that salt is harmful. Now possibly in more ways than was previously
known.

~~~
Retric
Salt intake over years is not the same as salt intake over a month making this
study meaningless in terms of long term heath impacts.

~~~
SepUltra
Nope.

~~~
Retric
The US recommended salt intake is limited to 1.5g to 2.3g grams of salt
depending on some risk factors. Their 'low' intake was 6g and high was 12grams
/ day.
[https://sodiumbreakup.heart.org/how_much_sodium_should_i_eat](https://sodiumbreakup.heart.org/how_much_sodium_should_i_eat)

So, I am saying almost 5x the recommended limit for a month might not
generalize very well. Sorry, 'Nope' is not going to cut it. Further, the human
body climatizes to various situations over time suck as heat or altitude, I
suspect salt intake is probably good example of that.

~~~
MandieD
A lot of the cross-talk in the whole salt/sodium debate is caused by
conflating salt (sodium chloride) with sodium, one of its constituents.

The US daily recommended _sodium_ intake is 1.5-2.3g. The sodium component of
sodium chloride is about 40%, so that's more like 3.75-5.75g of _salt_ per
day. Still lower than the study, but putting the higher recommended amount
right around the lower study amount.

(I consume up to an extra teaspoon of _salt_ each day to make sure I'm getting
at least 5000mg of _sodium_ so I don't start passing out at an inconvenient
moment, on advice of a cardiologist)

~~~
Retric
Good catch.

These are supposed to be limits not minimum recommendations. Also people get
sodium from more than just salt so 5.75g of salt is still high and calling 6g
low is kind of a misnomer.

------
jrapdx3
For the past year I've been on a low sodium diet, not so easy to achieve.
After reviewing the renal physiology I learned about years ago re: sodium and
calcium regulation, I'll testify it's every bit as complex as I remember and
then some.

I'll be interested in reading the articles the newspaper report is based on,
but ATM not sure how much the new findings contradict (vs. extend) what's
thought to be true about the physiological roles of sodium. In terms of
implications for health issues, conditions like hypertension are enormously
heterogeneous in origin, salt intake being only one factor among a huge number
of factors involved.

I was interested in the comment that high salt intake was potentially adverse
for bone health via glucocorticoid stimulation. One thing I've recently
learned is how high dietary sodium negatively affects bone calcium balance via
mechanisms within bone cells, and in some people, excessive renal calcium
excretion as well. These issues aren't AFAIK primarily mediated by elevated
cortisol. So it seems to be suggesting another way high sodium intake promotes
bone loss.

Goes to show we know a lot less than we think we know, in this case about body
regulation of essential minerals like sodium and calcium. When we realize that
also applies to every other factor we think related to high blood pressure or
osteoporosis, it's very humbling indeed.

~~~
epmaybe
A random theory, if you will: glucocorticoids have a weak affinity for the
mineralocorticoid receptors (aldosterone, salt and water retention). The
increased salt reabsorption caused by this could cause an osmotic gradient
driving calcium excretion.

It sounds a bit too complicated though, where a transporter would fit in
nicely.

~~~
jrapdx3
I don't have any direct info re: mineralocorticoid effect on renal
reabsorbtion of calcium, however the interaction of sodium and calcium has
been studied as it is important in kidney disease, for example kidney stones,
and osteoporosis as well. Here is an article on an excellent site that
discusses some of the significant aspects of sodium/calcium regulation:
[http://kidneystones.uchicago.edu/does-too-much-protein-
incre...](http://kidneystones.uchicago.edu/does-too-much-protein-increase-
stones-or-damage-bones/).

------
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?

~~~
stinos
_all the negative effects associated with increased salt intake are really
negative effects of overeating_

I'd also say that plays a role to some degree in real life, but only some. Net
effects of higher salt intake (given oter things remain equal) can exist as
well: the article clearly mentions higher salt intake leading to higher
glucocorticoid levels which in turn are linked to osteoporosis, muscle loss,
type 2 diabetes and other metabolic problems

------
reitanqild
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.

~~~
abovemypaygrade
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.

~~~
pilsetnieks
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.

~~~
int_19h
The real bad impact is from disrupting the way your kidneys work. Basically,
seawater has a higher concentration of salt than it is possible for your
kidneys to remove via urine (due to the physics of that process).

For one thing, your body will try to use its existing water supply to flush
the extra salt, which means that you'll be urinating (= dehydrating) more than
usual. Once that's all gone, and seawater is the sole source for water in your
body, your body will no longer be able to produce urine to carry the usual
toxins out. Eventually your kidneys will fail.

Although in practice, you will feel like a wreck both physically and mentally
long before then, and given that people in a situation where they can only
drink seawater generally have other dangerous conditions to deal with, these
debilitating effects can well kill you before that.

This also explains why diluting seawater is potentially viable - so long as
you keep the salt concentration below the level your kidneys can handle, you
can keep them working normally.

~~~
jaggederest
But the entire article is about the body using metabolic water, not dietary
water, to excrete salt. So it wouldn't matter the concentration of the salt in
the water you intake - your body would burn enough carbohydrates and protein
to generate enough water to dilute it.

I suppose in a starvation situation you'd be in extreme catabolism and just
make everything worse.

~~~
maxerickson
Seawater is 35 grams of salt per liter, so even modest consumption of it
involves considerably more salt than talked about in the study.

------
scandox
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?

~~~
Swizec
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.

~~~
PKop
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.

~~~
mistermann
I drink tons of water and I get lots of cramps, presumably from electrolyte
shortage. Is there any way of knowing what the right amount of salt is to be
consuming?

~~~
mtreis86
Rule of tongue - if it tastes salty its too much salt.

Take a half full water bottle. Add some salt. See if it is salty yet, then
keep adding until it is just barely salty. Then fill the bottle to the top. If
you taste salt you added too much.

Note that with kcl, you start with less water, more like a quarter of the
bottle, because the salty flavor is much weaker.

~~~
mistermann
This is with every bottle you drink? So basically once I figure out the
amount, I should put that much in _every time_ I get a fresh glass?

~~~
YeGoblynQueenne
Hey. If you're drinking lots of water and getting lots of cramps, don't ask
people on the internets. Ask a physician, right? If there's something wrong
with your kidneys, say, you won't make it better until you figure out what it
is.

~~~
mistermann
Very often people on the internet have more expertise in things than a
physician. Also, physicians are often overkill for minor problems, the system
would be overloaded if we went to them for every little thing.

------
xaedes
That is interesting. I see an advantage this adaption offers when trapped with
only salty sea water. Excessive salt intake may occur naturally when in the
ocean for whatever reason. When this reduces thirst and offers an (internal)
alternative for water this may help you survive until you strand somewhere to
find fresh water. Not the worst trait evolution could select for.

~~~
Freestyler_3
There is a negative side to it, you use up more calories.

(unrelated, I think fast food companies are already aware of the more hunger
from salty food.)

------
vmarsy
> Instead of drinking more, the crew were drinking less in the long run when
> getting more salt. So where was the excreted water coming from? “There was
> only one way to explain this phenomenon,” Dr. Titze said. “The body most
> likely had generated or produced water when salt intake was high.”

That's odd, what if simply a high-level of sodium reduces your perspiration?
Wikipedia[1] says "The volume of water lost in sweat daily is highly variable,
ranging from 100 to 8,000 mL/day." so between 0.1 and _8 liters_ per day! [2]
even says 10 to 12 liters per day!

If on average over a long period the subjects drank let's say exactly 1 liter
per day and peed strictly more than 1 liter of water, then I'd agree with what
this Dr. said, but neither this nytimes article, nor the 2 papers mentioned
[3][4] mention the word perspiration or sweat in their abstracts/summaries,
why not?

Off-topic: Did nytimes.com made it hard on purpose to select text from their
article? On Chrome and Firefox I can't select text easily, only Edge lets me.

[1]
[https://en.wikipedia.org/wiki/Perspiration](https://en.wikipedia.org/wiki/Perspiration)

[2]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2267797/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2267797/)

[3]
[https://www.jci.org/articles/view/88530](https://www.jci.org/articles/view/88530)

[4]
[https://www.jci.org/articles/view/88532](https://www.jci.org/articles/view/88532)

~~~
maxerickson
It's not odd though, water is one of the outputs of our energy metabolism.

------
Mz
_And, Dr. Titze said, high glucocorticoid levels are linked to such conditions
as osteoporosis, muscle loss, Type 2 diabetes and other metabolic problems._

And cystic fibrosis, which is perhaps best tldr'd as a salt wasting condition,
frequently leads to Cystic Fibrosis Related Diabetes, which is neither type 1
nor type 2 diabetes.

~~~
carbocation
CFTR, being a chloride channel, most likely leads to diabetes as a consequence
of its effects on the voltage-regulated insulin release in beta cells from
glucose sensing. [1]

It strikes me as unlikely to be related to the salt-wasting that occurs from
failure to reabsorb chloride in the epithelium.

1 =
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4104438/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4104438/)

~~~
Mz
I think it is probably a lot more complicated than that. CF does a great many
things to the body. It is an inflammatory condition and I have seen multiple
articles linking diabetes and inflammation. People with CF tend to be
seriously underweight and I have recently seen articles that link inadequate
muscle protein to insulin resistance. There is no doubt more than that going
on, those are just a couple of things that occur to me off the top of my head.

~~~
bdcravens
I have CF. About 2009 (age 32) I developed diabetes (commonly known as CFRD,
CF related diabetes). CF patients early on have the ducts in their pancreas
blocked from producing digestive enzymes, causing low weight. We take
digestive enzyme supplements to (inefficiently) counter this. (I realize you
have CF too - laying out background for the non-CF reader) My understanding is
that the eventual diabetes is caused by gradually decreasing pancreas
function.

~~~
Mz
I genuinely think it is a lot more complicated than that. My blood sugar is
more stable than it has ever been and I have gotten off digestive enzymes. I
wasn't doing anything to specifically try to fix my blood sugar issues. I was
doing things like trying to get inflammation and infection under control based
on the success of therapies like daily ibuprofen. I read up on that, inferred
that if you can reduce inflammation, you can be less symptomatic, and used a
dietary and lifestyle approach to do that. I did take ibuprofen daily for
something like 5 or 6 years, but was eventually able to successfully control
symptoms such that I no longer needed it. Somewhere along the way, I happened
to see articles about the link between diabetes and inflammation. Inflammation
and infection go hand in hand, so I think very likely infection plays a role
in the collapse of pancreatic function in pwcf.

The low weight is also from the gut being all kinds of out of whack and just
not absorbing nutrients. There are things that can be done to improve gut
function. The gut is about 70 percent of your immune system, so I think
efforts to repair the gut lead to many different good things, including better
nutritional status and a more functional immune system.

Though the degree to which you can correct these problems no doubt will be
influenced by which specific alleles you have, I think there is a lot of room
for improvement for most people with CF. Maybe it won't make much difference
if you have one of the variations where the CFTR just basically doesn't work
at all.

I used to jokingly talk about "Pale Skin Disorder" as a metaphor for special
needs in my kids. It works well as a metaphor for what I mean here too. If you
have pale skin (low melanin production) and are easily sun burned, there are
things you can do to protect against sunburn. You aren't doomed to simply be
sunburned to the point of peeling all the time. But if you are an albino and
totally lack melanin, it is a whole different ball game.

So, if you have a form of CF that is the equivalent of albinism where the CFTR
simply does nothing or is outright absent, instead of one of the many
variations where it has one of a number of different types of impairments, my
assumption is that would be less responsive to dietary and lifestyle changes.
Though I don't actually know.

Anyway, my apologies if I have offended. I rarely engage pwcf in discussion
anymore as it tends to go bad places. Thank you for commenting.

~~~
bdcravens
> Though the degree to which you can correct these problems no doubt will be
> influenced by which specific alleles you have, I think there is a lot of
> room for improvement for most people with CF. Maybe it won't make much
> difference if you have one of the variations where the CFTR just basically
> doesn't work at all.

I'm delta-f508 homozygous, so I suspect there's less CFTR function. I lose a
tremendous amount of salt when I sweat, so I suspect that's an indicator of
function level. Oddly enough, I've always had less respiratory issues for CF,
but my stomach pain and weight have been pretty severe as long as I can
remember. (I wasn't diagnosed about age 13, and I can remember intense pain
before then. When I'm religious about enzymes it's usually not an issue
however.) My A1C these days is poor, and my BGC always runs high. I could
probably counteract with diet, but then I have to contend to with keeping my
weight up. I suspect I may be a much lower pancreas function than what you're
describing.

> Anyway, my apologies if I have offended.

Not at all! I'll definitely look into inflammation etc.

~~~
Mz
Try adding aloe vera to your diet as a first step.

[http://miceats.blogspot.com/2016/09/aloe-
vera.html](http://miceats.blogspot.com/2016/09/aloe-vera.html)

------
tetraodonpuffer
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.

~~~
cannonpr
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.

~~~
dhimes
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 little, but to the "wow your blood
pressure is amazing" category (105 or 110). So, yeah, I don't think we know
how salt works.

NB my exercise/habits stayed pretty much the same in this period.

~~~
closure
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.

~~~
taneq
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.

~~~
iamacynic
not if you're the people who sell blood pressure medication...

~~~
taneq
True to your username... ;)

------
givan
Salt as far as I know is the only mineral (non plant) spice we use, it's
purpose is to enhance taste.

There is a common confusion between salt (sodium chloride) and sodium, many
falsely believing salt is not used only for taste but it's essential for
health.

Sodium is a vital element that is found in almost all plants and animals and
there is no need for an extra sodium intake because our food has plenty.

Sodium and potassium balance in the body is essential for cell physiology and
our health
[https://en.wikipedia.org/wiki/Na%2B/K%2B-ATPase](https://en.wikipedia.org/wiki/Na%2B/K%2B-ATPase)

I don't add salt in my food and avoid products with salt for more than a year,
"heavy food" doesn't feel as heavy, my skin is not as dry as before and looks
better and injuries seem to heal faster.

~~~
godmodus
human habits include many activities that consume a lot of water too - if you
drink alcohol, salt consumption on that day/night is a must!

i find adding some soysauce to a cup of water and chugging that before bed
takes care of most side effects.

and food does taste better with salt added, i must admit, esp. meat.

~~~
gosheroo
_> food does taste better with salt added_

Right, so the mode of intake matters, not just the salt itself.

For example one could eat bland (unsalted) food and drink salt water later
which would produce less pleasure for the same quantity of sodium consumed. So
there might be different physiological effects.

~~~
godmodus
taste + pleasure centers in the brain.

used to be useful when we were huntergatherers!

these days, it's just nice for food to taste good!

