
More scientists doubt salt is as bad for you as the government says - learc83
http://www.washingtonpost.com/blogs/wonkblog/wp/2015/04/06/more-scientists-doubt-salt-is-as-bad-for-you-as-the-government-says/
======
aabajian
>>How could something as simple as salt stymie scientists for so long?

The human body has numerous overlapping pathways for salt regulation. Salt
(sodium chloride) plays a major role in the osmolality (electrolyte
concentration) of blood. A drop in the sodium concentration results in the
release of renin, which causes changes in vascular constriction, sympathetic
activity, and sodium reabsorption itself.

This seems like a great research question for systems biology, although it
would require some detailed modeling.

~~~
s_q_b
Electrolyte balance in general seems like a good research question. We load
our food with sodium chloride, but natural diets are far higher in potassium
chloride. The relationship between the various electrolytes is something about
which we know very little.

~~~
logfromblammo
The function of the various proteins used in the sodium-potassium pump, which
transports Na+ out of cells and K+ into cells, against their natural diffusion
gradient, suggests that the ratio between Na+ ions and K+ ions in the diet,
and their relative concentrations in intercellular fluid is far more important
than the absolute quantity you consume.

If your Na+ to K+ balance is healthy, consuming too much of both could be
solved as easily as drinking more water.

But consuming too little of either one will cause the sodium-potassium pumps
to function poorly.

My hypothesis is that there is an optimal ratio of Na+ to K+ such that the
saltiest water (containing only NaCl and KCl) that a human could drink for
prolonged periods without observable ill effects has that ratio. A different
ratio would require more water for the kidneys to clear the ions present in
excess, and that would lower the total concentration of dissolved salts.

Learning that value could possibly enable the production of drinkable water by
partial desalination with potassium supplementation rather than complete
desalination. I have heard that water that is 40% seawater and 60% freshwater
can sustain someone in a survival emergency. Perhaps 50% seawater and 50%
dilute potassium chloride solution could extend the water supply on a life
raft by another 20%? You could hardly do the experiment if an ethical monitor
for human experimentation thinks that supplying that much of an absolute
quantity of dietary sodium is dangerous, independent of relative
concentrations.

~~~
s_q_b
Instinctually, I'd be a little wary of that, because Na+ and Ka+ do more than
act as ions within the neurological system. I'm not sure a higher
concentration, even at the right relative concentrations, wouldn't have
adverse effects.

~~~
logfromblammo
It's a bit difficult to figure out the highest concentration that doesn't have
adverse effects if you're not allowed to produce adverse effects.

~~~
s_q_b
We could probably do this with an animal model for testing, and work up to
human subjects pretty quickly.

------
AndrewOMartin
Ben Goldacre, who does a lot for public understanding of health and science,
among other things including being a GP for the NHS, is often asked for some
positive health advice after he warns about the worthless-at-best value of
most health advice. If I recall correctly, his response is always "Try to
increase the amount of fresh fruit and veg in your diet, try to reduce alcohol
and cigarettes, do some exercise.".

Also, this comedy sketch from Fry & Laurie is relevant, especially the "too
much is bad for you" rant at 2m00s.

[https://youtu.be/XV4yK-26smM](https://youtu.be/XV4yK-26smM)

~~~
leovonl
Fruit might be good for it's vitamins, but in moderation. Increasing fructose
consumption after a certain threshold - which could be easily crossed when
increasing it's consumption - would not necessarily be a good thing.

~~~
olau
Do you have a reputable source for that? Fruit is definitely good for more
than its vitamins.

Also, we are not monkeys anymore, but monkeys eat a lot of fresh raw fruit.
Arguably they climb trees while doing so but eating like a monkey seems like a
relatively safe thing to do to me.

~~~
logfromblammo
Elephants and manatees are closely related, as well, but I would not recommend
that they look to one another for dietary recommendations.

Speciation can occur when different populations fill different niches. Human
physiology (along with still extant hunter-gatherer cultures) indicates that
we are opportunistically omnivorous cursorial hunters. The species closest to
us genetically are opportunistically omnivorous frugivores. Chimps and bonobos
eat fruits and nuts most of the time, and eat monkeys maybe once a month. If
you want to consult the animal kingdom for dietary advice, look to wolves for
the meat and bears for everything else.

Eat like a bear until you see a potential prey animal, then run it down and
eat it like a wolf. When you finish, switch back to bear mode. That seems like
a relatively safe diet to me.

------
VLM
The article covers its chosen areas pretty well. Additionally, there are
aspects missed in the article.

The Puritan angle is important. If you're not making people feel guilty about
enjoying something, its hard to control them, and any attack on any form of
Puritanism is fundamentally an attack on all forms of Puritanism. So "salt is
OK" is going to fundamentally offend innumerable superficially unrelated
individuals who rely on guilt as social control in entirely non-food related
areas.

Tied in with the above, bland tasteless food isn't in as much demand as
flavorful tasty food. If the average American were dangerously anorexic then a
viable public health strategy would be to encourage salty food because it'll
taste somewhat better than bland salt free food and optimistically people will
eat more preventing anorexia. Obviously a visit to walmart will cure any
inaccurate belief about the average American being too skinny to be healthy.
So anti-salt is at least somewhat anti-obesity. Making stuff taste bad, is
good, if people are fat.

Finally (insert small percentage) of people are salt sensitive and it raises
their blood pressure. The other (vast majority percentage) just sweat or pee
out excess salt with no effect on their blood pressure. This results in two
interesting political issues. One is that financially we're better off telling
everyone to eat bland food so we don't have to spend money figuring out who's
in the susceptible minority or provide parallel logistical tracks of food. The
other is that the mere existence of differences offends certain political
beliefs about equality of outcome.

------
streptomycin
It's sad that we've known this for many years
[http://www.sciencemag.org/content/281/5379/898.summary](http://www.sciencemag.org/content/281/5379/898.summary)
but still incredible amounts of effort have been utterly wasted on pushing low
salt diets. And as the article describes, this will continue. Truly the study
of salt is political science.

------
raverbashing
Looks like the dietary "guidelines" of the past decades are essentially BS.
Especially the "low-fat" wave that came as a consequence.

At least low salt consumption has no consequences (of course if you abstain
completely from salt it will have, I'm talking about "normal" low consumption
here, however salt replacements, high in potassium, may have)

~~~
pygy_
> I'm talking about "normal" low consumption here

Well, not really:

FTA:

 _Then, this past August, the New England Journal of Medicine published the
results of a massive research effort known as the PURE study. It indicated
that people who conform to the U.S. recommended limits actually have more
heart trouble._

[...]

 _Under the current dietary guidelines, too much is more than 2,300 milligrams
of sodium per day - the amount of sodium in a teaspoon of salt. (For people
over 50, and for African-Americans, the current recommended intake is even
lower - 1,500 milligrams per day.)

If the U.S. salt warnings are correct, Americans are indeed endangering
themselves on a massive scale. Americans typically go way over the limit,
ingesting about 3,500 milligrams per day.

If the skeptics are correct, on the other hand, most Americans are fine. In
their view, a typical healthy person can consume as much as 6,000 milligrams
per day without significantly raising health risks. But consuming too little -
somewhere below 3,000 milligrams - also raises health risks, they say._

~~~
raverbashing
Interesting

I was thinking about this
[http://en.wikipedia.org/wiki/Hyponatremia](http://en.wikipedia.org/wiki/Hyponatremia)
but it's not necessarily caused by "too little salt"

------
jensen123
I wonder when they will stop with this one-size-fits all advice? I guess it's
because of this ideal that all humans are equal that pervades our culture,
which causes many to assume that all people are fundamentally the same.
However, every human is biochemically unique. A diet that works well for one
person doesn't necessarily work well for another.

I also think it's a mistake to look at any single nutrient or food in
isolation, and ask, is this healthy? It's impossible to answer that, because
whether or not something is healthy depends on the rest of the diet. For
example, is broccoli healthy? If the rest of your diet consists of fast food,
then clearly adding some broccoli would be a good idea. But if the rest of
your diet already contains tons and tons of vegetables, then perhaps you have
a serious gas problem, and you would be better off avoiding adding broccoli to
your diet.

EDIT: I remembered that I read somewhere that sodium "competes" with potassium
in the body. Apparently, if you consume a lot of potassium, then you can
tolerate more sodium.

------
hackuser
The headline and some commenters are misrepresenting the debate. From the
article:

 _Both sides agree that eating too much salt, especially for people with high
blood pressure, can be dangerous.

The critical disagreement concerns how to define "too much."

Under the current dietary guidelines, too much is more than 2,300 milligrams
of sodium per day

... If the skeptics are correct ... a typical healthy person can consume as
much as 6,000 milligrams per day without significantly raising health risks._

------
blackethylene
_For people over 50, and for African-Americans, the current recommended intake
is even lower - 1,500 milligrams per day._

I am intrigued by the current guideline for African-Americans. Does anyone
know what is the rationale behind this stricter limit?

~~~
SiVal
A greater incidence of high blood pressure, which salt is believed to
exacerbate.

~~~
JulianMorrison
I prescribe a diet of not being subject to the constant stress of racist
micro-aggressions.

~~~
vixen99
People with dark skin can experience vitamin D deficiency in northern
climates. One of the many symptoms is hypertension. Some estimates are that
you need 10 times more sun exposure to produce the same amount of vitamin D as
a person with pale skin.

~~~
JulianMorrison
This does not suggest reducing salt, but rather supplementing vitamin D. It
also doesn't rule out stress as a distinct, parallel cause.

~~~
vixen99
Who says it does?

------
annnnd
> The answer is that, despite the dietary claims that are made for all kinds
> of foods, actually substantiating how eating influences human health is
> notoriously difficult.

This. Have you noticed how recommendations change over years? Nutritionists
don't have much of a clue, but press usually takes them by the face value and
makes a new truth out of their words.

~~~
Retric
We actually know a lot about nutrition, but if something are good for A and
bad for B and you only learn about this stuff through several intermediaries.
Then it's going to come across in a very odd miss mash of conflicting reports.

Diabetes, heart disease, and Crohn's are just a few examples where diets can
make a huge difference.

Don't beleve me? Feel free to avoid vitamin C. Wait, no that’s a bad idea.

PS: Now if you’re in the search for optimum heath then yea that's a huge
unknown. But, if you ever talk to a nutritionist they can actually back up
their advice.

~~~
CWuestefeld
I don't think Crohn's fits your pattern here. My expertise/bias is that I've
had it for about 35 years.

The topic here is controlling body systems based on the _chemistry_ of what's
being consumed.

A Crohn's diet has two important factors, which don't really look at the
chemicals introduced into the body very much at all. Most important is a
purely mechanical component: because scar tissue and adhesions can cause
strictures, areas of limited diameter and stretch in the intestines, it's
necessary to avoid stuff that might get stuck, like popcorn and other seeds. A
second issue, possibly more important but only very poorly understood, is the
environment presented to intestinal flora. There's chemistry to that (like
carb mix) but, not with respect to the parent organism.

~~~
Retric
Most people with Chron's disease should avoid spicy food due to chemical
irritation and sure the mechanical issues are also important.

However, a nutritionist will suggest a _heathy_ low fiber diet when dealing
with a partial obstruction etc. Eggs vs red meat might seem like a simple
change, but once a range of dietary restrictions show up a heathy diet becomes
a lot more difficult.

Anyway my point was there is a lot of practical diet research out there.

PS: Chrones also frequently causes issues with nutrient absorption and a high
protein diet is useful for healing. So, there are some classically nutrition
based changes.

------
kazinator
Even if salt _per se_ isn't bad for you, if you avoid sodium, that forces you
to make healthier food choices. There is a correlation between "crap food" and
"loaded with salt". Or, more generally, "loaded with sodium".

This is simply because the addition of sodium compounds to food is a
processing step. Right off the bat, anything which contains lots of sodium is
almost certainly a processed food.

Let's look at it another way: Q: what do a slice of fresh meat or fish, a
carrot and an apple have in common? A: no added sodium! No salt, no baking
powder, no monosodium glutamate, ...

Salt is also abused by senseless cooks who don't take pride in creating
flavor. They just throw stuff together and douse it with salt. You can almost
measure a restaurant by how salty are the offerings. Approximately, the
saltier the cooking, the more they just care about money (and therefore use
lower quality ingredients, which they mask with salt or salt-containing
sauces, flavor enhancers like MSG, or excessive spicing).

------
eddiedunn
From my own experience, I'd say that the right amount of salt is highly
dependent on your diet. For example, when I restrict my carb intake I notice I
need to add more salt to my food or I will get cramps and feel generally
dehydrated. Drinking more water doesn't help, I just go to the bathroom more
often. Adding more salt to my food works, however.

Unfortunately, I can find absolutely no scientific evidence to back this
theory up. I just try to listen to the signals from my body, and it works for
me.

~~~
amyjess
One of the meds I'm on is a potassium-sparing diuretic (spironolactone), so I
actually need _more_ sodium than most people lest I mess up my electrolyte
balance and get leg cramps.

------
Oletros
Why salt has to be bleached and what minerals are added to it?

~~~
aabajian
I'm not sure what you mean by bleaching. Salt is a mineral (it's sodium
chloride - NaCl). The only other mineral "added to it" is iodine in iodized
salt. The iodine is added to prevent iodine deficiency.

~~~
danielam
Nothing to do with bleaching, but have you ever bothered to look up the actual
ingredients of table salt? Morton's, for instance, is >99% NaCl, yet also
contains dextrose and calcium silicate.

[http://www.mortonsalt.com/faqs/food-salt-
faqs](http://www.mortonsalt.com/faqs/food-salt-faqs)

------
rickdale
When I was younger I played competitive sports and used to suffer from
cramping relatively often. I cured this condition by adding a pinch of celtic
sea salt to a glass of water in the morning.

The only thing dangerous about salt is table salt that is bleached and has
chemicals added. If you can get good salts like himalayan pink salt and celtic
sea salt, you are in the money.

Salt is the most efficient nutrient for the body. Provides essential minerals
as well as a sleuth of other positive health properties.

edit: Pink salt is not pink because more chemicals were added.

Check out this link:
[http://healthwyze.org/index.php/component/content/article/11...](http://healthwyze.org/index.php/component/content/article/115-the-
truth-about-table-salt-and-the-chemical-industry.html)

 _The more common "refined" table salts have been been stripped of their
minerals during processing, which manufacturers then sell to supplement
companies. It makes the unmistakable point that the producers of table salts
are intentionally stripping what they know to be the most nutritious part of
the salt, and actually increasing profits by malnourishing their own
customers._

~~~
ceejayoz
> The only thing dangerous about salt is table salt that is bleached and has
> chemicals added. If you can get good salts like himalayan pink salt and
> celtic sea salt, you are in the money.

You're mixing paranoias here. Pink/sea salt differ from table salt primarily
in that they have _more_ chemicals - that's what gives them more color/flavor.
If you're concerned with the iodine supplementation, enjoy your goiter...

Fearmongering about bleach in salt is a little weird considering its chemical
formula is NaClO and its primary component is used to make your tap water safe
to drink. When used, it degrades to water and salt as the oxygen pops off to
oxidize impurities.

~~~
MrJagil
>When used, it degrades to water and salt as the oxygen pops off to oxidize
impurities.

Are you saying that the chlorine in drinking water turns to salt through
oxidization? How is the Na added, specifically? I'm asking because when I
moved to NYC from Denmark, I initially had a hard time _even eating salad_ at
restaurants because I could taste the chlorine from the tap water it was
rinsed in. Is it just because there will always be pure chlorine remnants in
the water?

I'm genuinely curious.

~~~
ceejayoz
The water supply around here uses sodium hypochlorite, not pure chlorine gas.

[http://en.wikipedia.org/wiki/Sodium_hypochlorite#Water_treat...](http://en.wikipedia.org/wiki/Sodium_hypochlorite#Water_treatment)

------
plongeur
At the end of the day it is utterly irrelevant ... the US has a major food
issue, only seconded by the fat Mexicans - and salt is certainly not any major
problem here. Most likely the findings simply imply that our body copes well
with a bit "too much" or "too little" salt intake from nuitrition. I mean you
still get plenty of "salt" from your water.

The problem is sugar, carbonhydrate-based food, red meat and fat, fat, fat -
everytime I watch documentaries about the US (f.x. about the fucked up prison
system) I wonder about how it is possible that almost every single police guy
or warden is that _fat_ \- or the other extreme a bulk of muscles. I mean
sorry - but salt - that's nothing the US has to worry about.

~~~
savanaly
Go back or forward or sideways a few months and you'll find people
authoritatively saying what you just said with all the nouns rearranged (turns
out fat isn't so bad! etc). Modern nutrition seems like an endless merry-go-
round mindfuck. (Not saying non-modern is any better of course)

~~~
plongeur
Of course "fat isn't so bad!" ... but it is, if you live off fast food like a
significant part of the US population.

Also "fat <> fat" ... I eat every day at least one tablespoon of linseed oil.
And that is very good for me and my brain :)

~~~
jjoonathan
And how exactly do you know that it is good for you and your brain?

