
It's Time to End the War on Salt - pitdesi
http://www.scientificamerican.com/article.cfm?id=its-time-to-end-the-war-on-salt&WT.mc_id=SA_20110721
======
bluena
Here's a big copy paste from Harvards school of public health:
www.hsph.harvard.edu/nutritionsource/salt/jama-sodium-study-flawed/index.html

A new study would have you believe that low-salt diets raise your risk of
dying from heart disease—a surprising finding, and one that’s sure to grab
headlines worldwide. The only problem is that the study’s conclusions are most
certainly wrong.

In the study, published in the May 4, 2011, issue of the Journal of the
American Medical Association (JAMA), European researchers followed 3,681 men
and women for an average of about eight years. (1) They report that people
with the lowest levels of sodium in their urine (a marker of salt intake) at
the start of the study had a 56 percent higher risk of dying from
cardiovascular disease than people with the highest levels. Equally
unexpectedly, among the 2,096 participants who had normal blood pressure at
the start of the study, urinary sodium appeared to have no effect on the
development of high blood pressure over six and a half years.

Based on these findings, the study authors call into question recent estimates
(2, 3) of the tens of thousands of heart attacks, strokes, and cardiac deaths
that could be averted each year—and the billions of healthcare dollars that
could be saved—by curbing Americans’ excessive salt intakes. Yet the study has
several weaknesses, chief among them its modest size: With less than 4,000
participants—and only 84 deaths due to cardiovascular disease—the study is too
small to support the authors’ sweeping conclusions.

Read about why cutting back on salt and sodium is a key to good health

Read about key studies that show the harmful effects of sodium on the heart

Furthermore, the study’s findings are inconsistent with a multitude of other
studies conducted over the past 25 years that show a clear and direct
relationship between high salt intakes and high blood pressure, and in turn,
cardiovascular disease risk. (4–10)

“Take this study with a huge grain of salt, and then dispose of it properly,”
says Dr. Walter Willett, chair of the Dept. of Nutrition at Harvard School of
Public Health. “This study should not influence recommendations about sodium
intake in any way.

Key problems that undermine the study’s conclusions include the following:

Unreliable measurement of sodium intake: The study investigators base their
main findings on a single measurement of sodium collected at the start of the
study specifically the amount of sodium that study participants excreted in
their urine over a 24 hour period. Yet sodium excretion from just one day does
not reflect people’s salt intake patterns over long periods of time. It’s weak
science to use one-day sodium excretion to predict heart disease or mortality
decades later. Failure to account for key factors that influence sodium intake
and heart disease risk: People who are taller (11) or more active (12) tend to
have a lower risk of heart disease. They also tend to have higher sodium
intakes, simply because they eat more food. Yet the JAMA study authors don’t
account for differences in height, physical activity, and total calories. (13)
This oversight could make it appear as though high sodium intakes protect
against heart disease deaths, when in fact physical activity or height is
responsible for the lowered risk. Other weaknesses: There are other problems
with the way that the investigators conducted the study, among them, missing
or incomplete data from large numbers of participants. The study
investigators, for example, could have accounted for incomplete urine samples
by analyzing urinary sodium in relation to creatinine (another compound found
in urine), but they did not.

The bottom line is that the researchers were trying to ask questions that
their data are incapable of answering, and the study’s many methodological
problems make its results unreliable. So the study’s findings do little to
refute the strong evidence that cutting back on sodium would save lives.

Americans, on average, consume about 3,400 milligrams of sodium per day.
Current U.S. recommendations call for a maximum of 2,300 milligrams of sodium
a day (the amount found in a teaspoon of salt), and 1,500 milligrams of sodium
(two-thirds of a teaspoon) for people who have high blood pressure or are at
high risk of developing it. The latter group includes people who are over the
age of 40, are African American, or have somewhat elevated blood pressure
(prehypertension)—a group that includes almost 70 percent of adults in the
United States. (14) A dash of prevention is worth a pound of cure: Since 90
percent of Americans will develop high blood pressure at some point in their
lives, (15) it really makes sense for all of us to curb our sodium intake.

Read more about how to preserve flavor and cut back on salt

Try these delicious low salt recipes from the Culinary Institute of America

Seventy-five percent of Americans’ sodium intake comes from processed foods.
(16) That’s why the Institute of Medicine has called on the U.S. Food and Drug
Administration to regulate the amount of salt and sodium allowed in processed
foods. (10) References

1\. Stolarz-Skrzypek K, Kuznetsova T, Thijs L, et al. Fatal and Nonfatal
Outcomes, Incidence of Hypertension, and Blood Pressure Changes in Relation to
Urinary Sodium Excretion. JAMA. 2011; 305:1777–85.

2\. Palar K, Sturm R. Potential societal savings from reduced sodium
consumption in the U.S. adult population. Am J Health PromotOpens in New
Window. 2009; 24:49–57.

3\. Bibbins-Domingo K, Chertow GM, Coxson PG, et al. Projected effect of
dietary salt reductions on future cardiovascular disease. N Engl J MedOpens in
New Window. 2010; 362:590–9.

4\. Strazzullo P, D'Elia L, Kandala NB, Cappuccio FP. Salt intake, stroke, and
cardiovascular disease: meta-analysis of prospective studies. BMJOpens in New
Window. 2009; 339:b4567.

5\. Intersalt: an international study of electrolyte excretion and blood
pressure. Results for 24 hour urinary sodium and potassium excretion.
Intersalt Cooperative Research Group. BMJOpens in New Window. 1988;
297:319–28.

6\. Cook NR, Cutler JA, Obarzanek E, et al. Long term effects of dietary
sodium reduction on cardiovascular disease outcomes: observational follow-up
of the trials of hypertension prevention (TOHP). BMJOpens in New Window. 2007;
334:885-8.

7\. Cook NR, Obarzanek E, Cutler JA, et al. Joint effects of sodium and
potassium intake on subsequent cardiovascular disease: the Trials of
Hypertension Prevention follow-up study. Arch Intern MedOpens in New Window.
2009; 169:32–40.

8\. Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of
dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl
J MedOpens in New Window. 1997; 336:1117–24.

9\. Sacks FM, Svetkey LP, Vollmer WM, et al. Effects on blood pressure of
reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH)
diet. DASH-Sodium Collaborative Research Group. N Engl J MedOpens in New
Window. 2001; 344:3–10.

10\. Institute of Medicine. Strategies to Reduce Sodium Intake in the United
StatesOpens in New Window. Washington D.C.: National Academies Press. 2010.
Accessed May 3, 2011.

11\. Ferrie JE, Langenberg C, Shipley MJ, Marmot MG. Birth weight, components
of height and coronary heart disease: evidence from the Whitehall II study.
Int J EpidemiolOpens in New Window. 2006; 35:1532–42.

12\. U.S. Dept. of Health and Human Services. 2008 Physical Activity
Guidelines for AmericansOpens in New Window. 2008. Accessed May 3, 2010.

13\. Willett W, Stampfer M. Implications of Total Energy Intake for
Epidemiologic Analysis. in Willett W, Nutritional Epidemiology. New York:
Oxford University Press, 1998: 273–301.

14\. Application of lower sodium intake recommendations to adults—United
States, 1999-2006. MMWR Morb Mortal Wkly RepOpens in New Window. 2009;
58:281–3.

15\. Vasan RS, Beiser A, Seshadri S, et al. Residual lifetime risk for
developing hypertension in middle-aged women and men: The Framingham Heart
Study. JAMAOpens in New Window. 2002; 287:1003–10.

16\. Brown IJ, Tzoulaki I, Candeias V, Elliott P. Salt intakes around the
world: implications for public health. Int J EpidemiolOpens in New Window.
2009; 38:791–813.

~~~
gojomo
Um, _why_ the giant copy & paste?

What would have been wrong with a clickable link
([http://www.hsph.harvard.edu/nutritionsource/salt/jama-
sodium...](http://www.hsph.harvard.edu/nutritionsource/salt/jama-sodium-study-
flawed/index.html)) and small salient excerpt?

Also, this Harvard article is strictly raising concerns about a May 2011 JAMA
paper. The Scientific American 'End the War on Salt' article also relies on a
"meta-analysis of seven studies" published in July, and talks of another
11-trial review of the effects of sodium-intake-reduction in 2004.

~~~
starwed
The SciAm article makes it sound like there is literally _no_ scientific
support in "the war against salt." This article pretty clearly claims exactly
the opposite, so it makes a good counterpoint even if it was published before
the most recent study.

> _Um, why the giant copy & paste?_

When I click on that link, a registration thingy pops up. You can dismiss it,
but OP might have thought registration was required.

------
alttag
While the causes of too much salt are debated, I see fairly regularly the
effects to _too little_ salt.

In a hot climate (Southeastern U.S.), I'm often outdoors with sports teams or
youth groups, and I see the effects of heat-related conditions regularly.
These are prevented and treated with water and salt (electrolytes). [1] [2]

So yeah, too much salt may be a problem. Maybe not. But too little certainly
is, and it's common in the active youth I observe.

1: <http://en.wikipedia.org/wiki/Hyperthermia> 2:
<http://en.wikipedia.org/wiki/Electrolyte>

~~~
michaelcampbell
Couple things here, and I say this with the utmost respect. Your anecdote is
not "data", and even if it were, you've failed to prove any sort of causality
of "too little salt". Salt is but one of many possible electrolytes, and and
"heat related conditions" are not necessarily solved with salt; chances are
dehydration clear and simple could also be the cause of the effects you're
seeing.

~~~
lukeschlather
Hyponaetremia is well-documented, and I'm sure someone who has spent a summer
supervising children in the heat can tell the difference between hyponaetremia
and dehydration. With utmost respect, you sound like you haven't had first aid
training and you don't spend much time outdoors in hot weather.

~~~
alttag
Thanks for the support. I think GP is right to be cautious (and data is not
necessarily equivalent to multiple anecdotes over more than a decade).
However, I would assert that my experiences are not unique.

You are correct that the symptoms are different [1][2], and that first aid
training (in my case, Red Cross) acknowledges the necessity of both fluids and
electrolytes.

More broadly, the term "[D]ehydration, despite the name, does not simply mean
loss of water, as water and solutes (mainly sodium) are usually lost in
roughly equal quantities" [3], meaning that even if water is replenished, salt
intake must also be increased.

It's been my experience (and we're back to anecdote, unsupported by my first
aid training) that dehydration may occur quickly (especially in hot weather),
but insufficient electrolytes occurs over a period of days of insufficient
replenishment (e.g., training, sports tournaments, resident camps).

1: <http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001431/> 2:
<http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001977/> 3:
<http://en.wikipedia.org/wiki/Dehydration>

------
carbocation
Two things.

1\. It's possible that we've reversed the causal association for all these
years. You don't always get expansion of the extracellular fluid space with
chronic kidney disease due to hypertension; with some tubulointerstitial
diseases, you develop salt-wasting nephropathies. Perhaps these were the
hypertensive patients who were referenced in the article, voraciously eating
salt due to a deficiency caused by their kidney disease? I'd like to see more
data before being willing to overturn dogma, but it's not the most outlandish
idea I've heard all day. Still, the authors' conclusions are most likely
wrong.

2\. There's a group at MGH doing a randomized clinical trial in which they are
administering intravenous salt and measuring near-term blood pressure
response. It's a one-off exposure, but it will be interesting to better nail
down the relationship between serum sodium content and blood pressure via
experiment rather than epidemiology.

~~~
cperciva
_It's possible that we've reversed the causal association for all these
years._

Another possibility: Cortisol. People under chronic stress produce more
cortisol, and high cortisol levels act to inhibit urinary sodium loss. Maybe
the people having heart attacks aren't _eating_ more sodium; they're just
retaining it better as a side effect of the stress which is killing them.

~~~
jonnathanson
Stress, cortisol, and let's not forget sleep deprivation -- also typically
associated with the same lifestyle, also highly deleterious to health, and
also correlated with heart disease.

~~~
cperciva
Right, my point was that cortisol is the link between "lifestyle which results
in early death" and elevated serum sodium.

~~~
jonnathanson
Understood your point; was just adding to it. Sorry for the confusion.

------
brudgers
> _But if the U.S. does conquer salt, what will we gain? Bland french fries,
> for sure. But a healthy nation? Not necessarily._

 _This week a meta-analysis of seven studies involving a total of 6,250
subjects in the American Journal of Hypertension found no strong evidence that
cutting salt intake reduces the risk for heart attacks, strokes or death in
people with normal or high blood pressure."_

The article goes out of its way to dismiss the other impact of "French Fries"
on health, obesity, and the role which salt plays in making manufactured food
with low nutritional value habit forming.

[http://www.sciencedaily.com/releases/2006/11/061101151027.ht...](http://www.sciencedaily.com/releases/2006/11/061101151027.htm)

~~~
DannoHung
Which seems to be mainly down to drinking more non-water liquids.

So... maybe the effort expended in reducing salt intake should instead be
spent on increasing water as a beverage choice?

~~~
brudgers
Seems to me, that if people would readily forgo consuming flavored food
products in lieu of something with little taste, a correlation between salt
and obesity might be less likely to begin with. In other words, one could
promote carrots in lieu of French Fries and expect similar results.

------
jdee
The entire process of diagnosing people with hypertension needs a shake up.
Managing blood pressure is such an important part of the human condition but
the evidence as to what works and what doesnt can be confusing. Weight loss
and stopping smoking works, but for exercise, cutting alchohol and cutting
salt there are many conflicting reports.

Add in the fact that genetics plays such an important part, and the prevelence
of White Coat Syndrome it's a shame that the medical world cannot make its
mind up.

~~~
ern
The confusion around hypertension is really annoying. I have a bit of white
coat hypertension, and my BP is usually around 145/80 when measured by a
medical professional, but is still around 132/80 when measured automatically.
Getting it down to 120/80, or lower (where everyone else who I know in my age
group is, and which _seems_ to be the safest in the long term) is stubbornly
impossible, despite exercise and a healthy diet. A 24 hour workup by a doctor
seemed to point to stress-induced hypertension, but I was told that there's no
need to treat it.

Is hypertension brought on by being stressed/awake less harmful than
"intrinsic" hypertension? That seems to be the opinion by my physician. But
it's maddening that these issues remain unresolved.

~~~
Devilboy
What exactly do you eat / drink on an average day?

~~~
ern
I usually have a cup of tea for breakfast and grilled cheese + tomato
sandwitch for lunch. Dinner is either poached fish, grilled or curried
chicken, steak or lambchops, and often features french fries or rice. Popcorn
for a late snack. No alcohol. I avoid coffee, but have 2-3 packets of potato
chips and the equivalent of 2 glasses of Coke a day (I think I'm
hypersensitive to caffeine, and any caffeine after 4PM screws with my sleeping
patterns). 2-3 eggs on weekends.

At one stage I had salad for lunch for about a year, and tried to eat
vegetables 5 days a week, but it didn't seem to influence my BP.

I exercise a lot less than I used to, but when I exercised 4 times a week, I'd
regularly check my BP before starting, and, if anything, it was higher than it
is now. But I am trying to psych myself up for exercise for other reasons - I
need to offset the general malaise that comes from being behind a desk the
whole day.

~~~
muraiki
While I don't know what such a diet means for hypertension, it sounds pretty
poor in terms of nutritional value. You might have less malaise if you ate
more fruits and vegetables, and weren't sending your blood sugar on a roller
coaster with those two glasses of coke. Two cans of coke supplies over a
quarter of the recommended daily carbohydrate intake!

Try eating nuts or seeds as a snack. The protein will help balance your energy
levels and the fat will keep you satiated. Look at granola instead of potato
chips -- not the top brand ones bars that are just sugar delivery mechanisms,
though.

And really, you should eat breakfast! The first meal of the day has a lot of
important effects. <http://www.webmd.com/diet/guide/most-important-meal>

~~~
lupatus
I sleep ~6 hours per night, drink 6+ cups of coffee and 1-2 cups of tea per
day, and only rigorously exercise for 25 minutes 2-3 times per month. My daily
diet consists of 600+ calories from extra-virgin cold-pressed coconut oil and
butter, 2-4 eggs a day, a handful of cherry tomatoes, 1000+ calories from
beef/poultry/pork/fish, 400+ cals from hard cheeses (like swiss), a 1/2 pound
- 1 pound of vegetables, maybe a handful of mixed nuts, and a whole lot of
kitchen spices (including salt!).

I also try to take 5 - 10 minutes a day to do focused breathing/relaxation
(i.e. meditation w/o the hocus-pocus).

With the above lifestyle, I have a resting pulse rate of 54, a bp of 122/70,
and I have been losing 2-8 lbs a month for the past 18 months while
maintaining strength, endurance, and muscle mass levels. Moreover, I feel
wonderful!

I turn 30 at the end of the year, so my good results aren't because I am some
youthful, exuberant teenager. I actually attribute them to my diet and
lifestyle.

~~~
Poyeyo
Traditional 'healthy' diet (low fat, low salt, high on carbs and grains) is
very bad for health.

Your diet seems to be mostly keto (I assume your coffee and tea are
sugarless). The diet of ern is very far from keto.

There are two very active community of redditors (keto and Paleo) with very
good info on diets and foods that work to have good health, and bibliographies
with explanations of why it works.

~~~
lupatus
I like to think of my diet as "early-Neolithic". I am from one of the
populations groups with adult lactose tolerance. So, I modeled it on the foods
that might be available to what used to be called a "gentleman farmer".

I also recognize that scientific research has made real progress on
determining what to eat in the past few years; so, I've also tried to
incorporate some of those findings as well.

------
pradocchia
For reference, and for those who may not have already read it:

"The (Political) Science of Salt", Gary Taubes. Science. 1998. 281: 5379;
898-907

[http://web.archive.org/web/20060923051143/http://www.nasw.or...](http://web.archive.org/web/20060923051143/http://www.nasw.org/awards/1999/99Taubesarticle1.htm)

~~~
greenyoda
Here's a link to this paper that's a single page and doesn't require going
through archive.org:

[http://storyarchive.tumblr.com/post/9437438977/the-
political...](http://storyarchive.tumblr.com/post/9437438977/the-political-
science-of-salt-gary-taubes-science)

------
brg
While tangentially related, I am compelled to deliver a pointer to Alton
Brown's special on the mysterious mineral which is salt, Eat-This-Rock.

[http://www.foodnetwork.com/good-eats/good-eats-eat-this-
rock...](http://www.foodnetwork.com/good-eats/good-eats-eat-this-
rock/index.html)

Or for the brave: <http://www.youtube.com/watch?v=0f62XQPBlTE>

------
felipemnoa
Interesting bit:

>>In May European researchers publishing in the Journal of the American
Medical Association reported that the less sodium that study subjects excreted
in their urine—an excellent measure of prior consumption—the greater their
risk was of dying from heart disease. These findings call into question the
common wisdom that excess salt is bad for you <<

If I'm reading this correctly it is saying that people that urinate less
sodium have higher chances of dying from heart disease. Then the author uses
this as evidence that less sodium actually increase your chances of dying from
heart disease.

If so then I would hypothesize that less sodium could simply mean that the
body is no longer able to expunge it from the body and hence that is what is
causing the heart disease.

~~~
JacobAldridge
_"less sodium [output] could simply mean that the body is no longer able to
expunge it from the body"_

 _"the less sodium that study subjects excreted in their urine - an excellent
measure of prior consumption"_

These two statements seem mutually exclusive. If the amount of sodium a
subject excretes is an excellent measure of prior consumption (ie, more out is
demonstrably linked with more in, and less out = less in), then your
hypothesis (less out may mean more retained, and therefore output can't be
linked to input) cannot be true.

Of course, it could also be the "excellent measure" which is incorrect - my
point is simply that these two are contradictory.

~~~
felipemnoa
>>my point is simply that these two are contradictory

My hypothesis assumes that the following statement is false on sick
individuals.

>>"the less sodium that study subjects excreted in their urine - an excellent
measure of prior consumption

Hence there would be no contradiction.

~~~
JacobAldridge
You're assuming that statement is false in specific cases; the OP assumes it
is true in all cases - that sounds like a contradiction to me.

------
Lost_BiomedE
IMO, one of the most overlooked variables in the great salt debate is
potassium deficiency:

'The 2004 guidelines of the Institute of Medicine specify an RDA of 4700 mg of
potassium for adults,[2] based on intake levels that have been found to lower
blood pressure, reduce salt sensitivity, and minimize the risk of kidney
stones. However, most Americans consume only half that amount per day.'

Personally, I think we have a potassium, weight, and pre-diabetic problem, not
a salt problem.

------
e2daipi
Not much more to say after Tim Harford…

MoreOrLess: Is salt bad for you? 19 Aug 2011

[http://itunes.apple.com/gb/podcast/more-or-less-behind-
the-s...](http://itunes.apple.com/gb/podcast/more-or-less-behind-the-
stats/id267300884#)

Starts at about 00:45 up to 16:07.

------
S_A_P
Anecdotal, I know, but in my experience my blood pressure is directly
correlated with alcohol consumption. I used to be a consumer of 2-3 beers
daily. At this time, I was also running approximately 15 miles per week, and
working out at the gym. I was about 20 lbs heavier and had borderline high
blood pressure. One day I cut out the beer intake, pretty much completely. The
20 lbs have fallen off, blood pressure is normal to below, and I cut back my
running to 3-5 miles per week. I crave salt and eat plenty of it with an
otherwise healthyish diet(that didnt change)

------
dr_
I understand their position up until the point of The NEJM Feb 2010 study,
where they are dismissive of it as "conjecture". Granted it's a computer
simulated model but they are using valid data from the National Health and
Nutrition Examination Survey and the Framingham Heart Study.

------
pbhjpbhj
Do they still treat hypotension by increasing a patients dietary salt intake?

------
alatkins
Once again, yet another diet-related study which reinforces the old maxim of
_everything in moderation_ (including moderation, of course :-)).

------
gerggerg
I wish this article was programming related somehow.

~~~
marshray
A lot of us partake in the coffee and/or diet soda while programming. This
jacks with our BP and invariably the subject of sodium comes up.

------
crag
And it's about time. :)

------
lukifer
a) War on ______ tends to be a sensationalist phrase that causes me to flip
the bozo bit.

b) This article doesn't have anything whatsoever to do with tech or startups.

~~~
PakG1
For (b), a lot of articles submitted here have nothing to do with tech or
startups. That doesn't mean we wouldn't be interested in reading them. I think
the HN community tends to know what the HN community wants to read more often
than not.

~~~
hessenwolf
Technology, startups, business, and workaholics' diseases. I also think they
fit fairly well together.

