Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
12 Jun

Salt: What Is It Good For?

saltOther than saturated fat, I can’t think of a nutrient that’s been so universally maligned and demonized as salt. All the experts hate it and recommend that we get as little of it as possible. They even all seem to have their own little anti-salt slogans. The American Diabetes Association recommends between 2300 and 1500 mg of sodium per day (“Be Sodium Savvy“). The American Heart Association wants you eating less than 1500 mg per day (“Shaking the Salt Habit“) and claims that 97% of young people already eat way too much salt. The other ADA – the American Dietetic Association – also recommends between 2300 and 1500 mg, but their slogan is far inferior (“Slice Your Sodium Intake“). It’s quite the pile-on, isn’t it?

Why does salt strike mortal terror into the hearts of so many?

Back in the 1980s, a massive global study of salt intake and blood pressure called INTERSALT was undertaken. Overall, it showed a modest association between the two, but some groups, particularly the undeveloped, non-industrial peoples who had very little access to salt (and other trappings of industrialization), had blood pressure that was generally extremely low. Foremost among these groups were the Yanomami of the Amazon rainforest. The Yanomami have very low sodium excretion, which indicates very low sodium intake, and very low blood pressure. Even the elderly Yanomami enjoyed low blood pressure. This was convincing. I mean, it sounds convincing, right? Low salt intake, low lifelong incidence of hypertension – how much more cut and dry can you get? This low salt/low blood pressure connection seemed to also apply to other groups who happened to be living more traditional ways of life.

Except that there’s another non-industrialized group (and you only need one) whose slightly different results kinda muck up the Yanomami argument: the Kuna of Panama.

Among the Kuna, a tribe native to Panama, both salt intake and blood pressure were also historically low well into old age. To study whether the two variables were linked, researchers examined a group of “acculturated” Kuna with ample access to salt and an otherwise strict adherence to their traditional way of life. Little changed but the salt intake, in other words. But, despite consuming an average of 2.6 daily teaspoons of salt (and sometimes up to 6 teaspoons), the Kuna did not have hypertension, not even in old age. There was no change between the hypertensive statuses of 20 year old Kuna and 60 year old Kuna.

All in all, drastic reduction of sodium can reduce blood pressure by a few points. The evidence is pretty consistent on that. But the example of the Kuna shows that there’s way more to blood pressure than how much salt you eat, like how much potassium you eat.

Consider two recent Cochrane meta-analyses. The first, on sodium restriction and blood pressure, found that for people with hypertension the mean effect of sodium restriction was -5.39 mm Hg for systolic blood pressure and -2.82 mm Hg for diastolic blood pressure. In normotensive people, the figures were -2.42 mm Hg and -1.00 mm Hg, respectively. Decent reductions, I suppose, but what about potassium and blood pressure?

The upper intake of potassium was associated with over a 7-point drop in systolic blood pressure and a 2-point drop in diastolic blood pressure, but only in people with hypertension (the people who actually should lower blood pressure). Unfortunately, the official recommendations for sodium and potassium intake cannot be met simultaneously. Yep – the experts want you to eat in a way that is literally impossible to accomplish. Inspires confidence, doesn’t it?

Let’s forget about blood pressure for a second, because there’s also way more to health than the meager drops in blood pressure afforded by sodium restriction. Recent evidence suggests that for many people, all out salt reduction has an overall negative impact on several other aspects of health:

In 2011, one study showed that seven days on a low salt diet increased insulin resistance in healthy men and women when compared to a higher-salt diet.

Another study showed that while reducing salt moderately improved the blood pressure of hypertensive patients by a mere 4.18 and 1.98 points for systolic and diastolic, respectively (but not of people with normal blood pressure), it also had negative effects on multiple other health markers, including increased triglycerides and LDL and elevated stress hormones.

Another 2011 study found that eating a low salt diet (under 3 grams of sodium per day, or just over a teaspoon of salt) and a high salt diet (from 6-7 grams of sodium per day, or well over two teaspoons of salt) both increased the risk of stroke and heart attack, while eating between four and six grams of sodium, or about two teaspoons of salt, each day was associated with the lowest risk of cardiovascular incidents.

A recent study found that salt intake followed a J-curve, with low and high intakes increasing arterial plaque formation and a medium intake decreasing it.

Sodium depletion due to “low-sodium nutrition” has been shown to trigger overtraining-like symptoms, including hypertension and sleeping disorders.

The greatest health marker of all – being alive – also has an interesting association with salt intake. It seems that, time and time again, folks with a “medium” salt intake live longer than people who eat too little salt or too much salt. That amounts to roughly 4000 mg of sodium, or close to two teaspoons of regular salt.

Sodium intake affects other markers of vascular health beyond just blood pressure, too:

Greater sodium excretion in the urine (a common marker of sodium intake) may be positively associated with large arterial compliance. Large arterial compliance is a measure of arterial elasticity, or the ability of one’s arteries to handle fluctuations in pressure. Stiffer arteries are more prone to damage.

Low sodium status (whether dietarily-induced or caused by increased sodium loss) can also increase aldosterone, an adrenal hormone that seeks to preserve sodium in the body when it’s perceived to be scarce. High aldosterone levels are associated with insulin resistance, and aldosterone blockers are being explored as potential treatments of vascular disease and hypertension.

Well, what is salt good for?

That question honestly isn’t asked very often in the literature, but we can surmise some of the benefits just by looking at what happens in people on a low-sodium diet. If that connection persists, then adequate (not excess) salt probably helps prevent some of those problems, like insulin resistance, plaque formation, increased stress hormones, worsened blood lipids, and elevated aldosterone.

There are, however, outright positive effects of salt consumption, too:

Salt supports hydration, especially during exercise.

Of the electrolytes, potassium gets all the attention, even though sodium is just as important. Studies show that sodium loading before exercising in the heat increases fluid volume and reduces the physiological strain of the subsequent training. In other words, consuming sodium before training “involved less thermoregulatory and perceived strain during exercise and increased exercise capacity in warm conditions.” You can workout harder, longer, and more effectively with sufficient sodium in your diet. Salt loading also boosts performance in thermoneutral conditions, not just hot weather.

I remember drinking so much plain water during one race that I actually became dehydrated from pissing out all my electrolyte stores and almost passed out. From that point on, a few teaspoons of salt would solve the problem and prevent it from occurring again. The much ballyhooed bananas didn’t do it. Only pure, unmitigated salt did the trick. Hardcore ketogenic athlete/doctor Peter Attia does the same with his bullion cubes, which he credits for maintaining his performance.

Salt may help you cope with stress.

This is a guess on my part, based on several lines of evidence. First, salt has been shown to speed up cortisol clearance from the blood. The faster you clear cortisol, the quicker you recover from a stressor. If cortisol lingers, you “stay stressed.”

Second, there’s evidence that stress increases salt appetite. In lab mice, activation of the sympathetic nervous system by a stressor causes them to prefer salt water to plain water. Similar findings have been observed in rats subjected to stress. In humans, acute bouts of stress don’t seem to increase salt appetite, but chronic stress does increase intake of salty, processed junk food. Obviously, eating McDonald’s fries doesn’t help improve your health, but I find it highly plausible that salting your healthy Primal food to taste could be an important ally against stress. It’s just that when most people need “something salty,” they reach for potato chips, not a couple soft boiled eggs dipped in sea salt.

Third, as I mentioned above, low sodium diets are often associated with elevated stress hormones.

Personally, I’m drawn to salty foods – often jerky or macadamia nuts sprinkled with some sea salt – when I’m up against a deadline, and it seems to help.

It makes food taste better.

Yes, some people would claim this attribute as a negative. Adding salt to food will make you more likely to overeat and gain weight and develop the diseases associated with weight gain and so on and so forth. But I’ve always held that eating good food is one of life’s highest, purest pleasures. If your food doesn’t taste good, there’s no point in eating it. We’re not machines concerned only with fuel. We are sensory, sensual beings with the capacity for appreciation of thousands of flavors. To deny the pleasure of food is to deny our humanity.

Salt can also make otherwise unpalatable – but healthy – food somehow palatable. A plate of steamed kale is boring and bitter. A plate of steamed kale with sea salt and olive oil is delicious and inspiring. Plain broccoli? Kids everywhere are spitting it into napkins and stuffing them into their pockets. Broccoli stir-fried with soy sauce (or tamari, if you please)? Kids everywhere are mailing in their dues (and signing up for auto-pay) for the clean plate club.

You could drop your salt intake to half a teaspoon and get a three or four point drop in your blood pressure. Of course, you might not enjoy your food anymore, your performance in the gym or on the trail would likely suffer, your stress hormones might be elevated, you might start feeling overtrained without doing any actual training, you could become insulin resistant, and you may have trouble clearing (the elevated) cortisol from your blood. But, hey: your blood pressure readings will likely improve by a few points! Or, you could keep your salt intake up around two teaspoons, give or take, simply by salting your food to taste, and avoid all that other stuff.

Your choice.

What do you think, readers? Do you fear salt? Do you relish it? Do you find your salt appetite increases under certain conditions? Let me know in the comment section!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. I do not add salt to anything and I find it tastes just fine. However I am sure my ancestors spent a lot of time by the sea fishing for crabs and fish and eating healthy seaweed and I bet there was an awful lot of sale as those products came out of salt water.

    Also historically some cultures used salt like Gold, of huge value to trade etc and deer seek out salt licks in forests. However I suppose sugar was also a kind of Gold to trade so that does not necessarily mean it was good for us.

    I do eat bacon every day so that will be full of salt anyway. I am sure I get more than enough but I just don’t want to add it to any food. Works for me.

    EnglishRose2012 wrote on June 14th, 2013
    • Sugar was incredibly good for us back when starvation was an ever-present threat. Calories matter more to a person on the brink of stavation than anything else, so sugar was gold – we’re just living in a very rich era right now. :)

      Patrick wrote on June 14th, 2013
      • That’s true. The history of salt is quite interesting – http://en.wikipedia.org/wiki/History_of_salt The expression “worth your salt” from Romans paid in salt etc.

        It sounds like it was valuable as it enabled preservation of food so removed some of the need to find food every day. Seems like it was also used in war.
        I wonder if it’s value came about because of preservative qualities though or because people knew they would die without it even if they gathered their food every day with no salt added.

        EnglishRose2012 wrote on June 14th, 2013
  2. I don’t know, I’m still not convinced that salt, isn’t as bad as is presented.
    I eat a low amount of salt (about half teaspoon, sometimes a teaspoon a day) and I have good blood pressure (about 120/80, which is great actually).

    Denis wrote on June 14th, 2013
    • With respect, mine’s lower and I eat far more salt than that, though of course maybe the amount you eat is right for you – one thing the primal/low carb community generally find is that dietary tweaks that are ideal for one person are bad for another, and this is what places us often at odds with over-arching government advice that everyone should be eating 11 portions of starches a day etc. :)

      Patrick wrote on June 15th, 2013
  3. Let’s not fail to mention that the table salt you buy at the grocery and REAL salt differ greatly. Table salt is almost entirely sodium (and iodine), processed to remove nearly everything except sodium, but real sea salt contains a myriad of minerals (at least 60 trace minerals) needed for a healthy system. Many people would do well to simply switch to Celtic or Himalayan sea salt (actual sea salt, not the processed stuff in the store labeled sea salt that is the exact same stuff in the other containers) which cuts down the sodium and brings their minerals into balance. The point being that salt has its place, but just like everything else we have turned something beneficial into something harmful.

    Angie wrote on June 14th, 2013
  4. Great post. I couldn’t agree more.

    I also think any future edits of the Primal Blueprint food pyramid should have salt at the very top of it.

    Christoph Dollis wrote on June 15th, 2013
  5. My family has been one to blame salt for many ills. However, I did at least introduce the idea that maybe salt (sodium chloride) isn’t so much to blame as some of the other sodium compounds; namely sodium benzoate, sodium nitrate, sodium nitrite, sodium erythorbate, to name a few. For overall flavor, I like sea salt the best. I’ve messed myself up with bad eating habits for 46 years and the pounds simply will not come off and stay off without a fight. I have found that I feel the best when I eat the Weston A. Price diet minus the grains and legumes; with a possible exception of sprouted brown rice on the 80/20 principle. And while the pounds are slow to come off, at least my dental checkups are good and the cavities on my wisdom teeth have healed. I think the name for this way-of-eating is Paleo 2.0 or the Optimal Paleo Diet (Primal?).

    James wrote on June 16th, 2013
  6. Wow, who knew!? As an athlete competing in CrossFit I realize my salt levels are NOT where they should be. Does 4000 mg apply to those less active? Say, with office jobs and little to no exercising?

    ~B

    Brooler wrote on June 17th, 2013
  7. Also, I’ve heard that harvested vs. processed salt is the way to go. Like sea salt or himilayan vs. table salt. Thoughts anyone?

    Brooler wrote on June 17th, 2013
  8. What happened with me is at one point I had a pretty clean diet and I wasn’t using any salt. When my regular old western doctor did some blood work on me it came back showing a slight deficiency and he recommended I start using more salt…
    So now I salt to taste and I still don’t need that much.

    Amy D wrote on June 17th, 2013
  9. I wonder if this is the reason I occasionally have the desire to drink soy sauce.

    I know, worchestershire sauce or sea salt is the proper response.

    But I’m a real-foodie who doesn’t react well to a full paleo diet and I don’t add salt to anything, I just get what is in the meat.

    Kelekona wrote on June 17th, 2013
  10. Interesting article. When doing a lot of long distance you loose a lot of salt and need to put it back. I was wondering, since salt is a mineral we have to mine from the earth; how would our ancestors have gotten enough salt? Where would it come from?

    Peter wrote on June 28th, 2013
  11. Hahaha… i would be more worried about sugar than salt!
    Diabetes is far more serious than CV diseases caused by salt.

    Chris wrote on August 22nd, 2013
  12. I can’t live without salt lol. that’s it! :P

    Chris wrote on August 30th, 2013
  13. I hope extra salt is good for health or at least not detrimental. Recently someone gave me over a pound of sea salt so I’ve been using excessive amounts.
    It seems to make me feel better… with the hot weather and some sweating I think extra salt is justified.

    Animanarchy wrote on September 10th, 2013
  14. Deark mark,

    what about fluid retaining and sodium…
    My cardiologist had me on a max 2000mg sodium intake per day for the last 10 years. He did that to limit the water retaining in my body as my heart isn’t strong enough to get rid of it on it’s own.
    My new doctor is quite shocked by my only average of 800mg of sodium a day and if your research is correct than he had all the right to be shocked.
    However your article with the exception of fluids and sports is mainly based on blood presure and cardio-vascular issues.
    What is the link between fluid-retention and eating sodium?

    marielleGO wrote on November 6th, 2013
  15. salt is one of the best things that happened to me, especially in angus burgers from mcdonalds every friday after school

    dana matherson wrote on November 14th, 2013
  16. I have always had low blood pressure. I once was convinced I needed to go low sodium for my health b/c heart disease runs in my family. I started getting leg cramps and feeling faint. I have discovered if I don’t eat enough salt my blood pressure goes too low and I am liable to faint and get leg cramps. So now I make sure I salt my food to taste so I don’t start to feel faint and have an accident. I think a blanket statement that everyone should be on a low sodium diet does a disservice to people like me who have low blood pressure. From your article we all should have a moderate sodium intake and eat our fruits and vegetable to increase our potassium and overall health! Balance in everything! Thanks for posting!

    Megan wrote on June 11th, 2014

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