Book Review: The Salt Fix (and a look at sodium)

“Modern medicine diverted us from our evolutionary path when it decided that salt was a toxic, addictive, non-essential food additive. The seeds of this destructive myth were sown one hundred years ago, but we are still bearing the costs now.” (p.30)

“As is clear from the medical literature, as well as the population-based studies, low-salt guidelines are not ‘the ideal.’ They are not even innocuous. We may someday discover that the low-salt guidelines created more heart disease than they ever prevented.” (p.89)

Those are some pretty hefty claims, and it would take some pretty hefty research to back them up. Fortunately, James DiNicolantonio, PharmD, has done the heavy lifting for us in his new book, The Salt Fix: Why the Experts Got It All Wrong--and How Eating More Might Save Your Life. That’s an ambitious title, but after reading the book, you might find it hard to refute.

Before I get into the review, in the interest of full disclosure, allow me to declare that I received a courtesy copy of this book. I also collaborated with Dr. DiNicolantonio on my very first peer-reviewed journal article, so obviously, I respect him and his work. That being said, if I thought the book was lackluster, I’d tell you so. Fortunately, that is not the case, so I can give you my honest assessment of the book and still stay in my friend and colleague’s good graces.     

On to the details!

If you read my blog because you follow a low carb, ketogenic, or Paleo-type diet (or are thinking about starting one), then you probably already have an understanding of how we, as a society, were misled regarding the supposed dangers of dietary saturated fat and cholesterol. In fact, even with tons and tons of evidence to the contrary, the medical powers that be are still trying to convince us there’s something inherently deadly about saturated fat. (They’re wrong.) We were also misled somewhat about the health-promoting effects of whole grains and polyunsaturated vegetable oils, and if we were looking to lose weight, we were inundated with advice to cut calories, especially from fat—more advice that failed countless numbers of us. Considering this unblemished track record of wrongness, we have to ask ourselves if “the experts” got it wrong on sodium, too. Dr. DiNicolantonio certainly makes a strong case for exactly this.

If you’ve long since abandoned fears about consuming egg yolks, butter, and beef, but trepidation lingers about sodium and you find yourself buying reduced sodium bacon or other low- and no-salt items, this book is for you. And if you have family members with hypertension (high blood pressure) who’ve banished the salt shaker from the kitchen table under doctor’s orders, this is even more for them!

(Note: going forward, I will use the terms sodium and salt interchangeably. They are not the same thing, though, as salt—that is, table salt, or NaCl—is sodium and chloride. For the purposes of this blog post, though, we’ll consider them as the same thing. Some foods naturally contain sodium—even vegetables and fruit—but we get the vast majority of dietary sodium from salt, whether it’s salt we add while cooking at home, or salt used as a preservative or flavor enhancer in packaged foods.)

Ooookay!

The first thing we need to establish is that sodium is an essential nutrient. Like magnesium, like manganese, like any other essential nutrient, we have to eat some. We have to. I want to say the reason salty foods are so delicious is that our bodies innately “know” that we need salt, and in order to make sure we get enough of it, it makes salty foods especially palatable to us. Unfortunately, we could use the same logic with sugar, and say that sugary foods are darn near irresistible to us because, well, maybe our bodies need glucose and fructose, and this is nature/evolution’s way of ensuring we get some. This is faulty logic, though, because we know we don’t “need” any dietary glucose at all. It’s still a decent argument for sodium, though, because here’s the deal:

Even though salty foods are delicious—and we could say the same for foods that are high in protein and fat, like a ribeye steak or a fatty pork chop—we eventually reach a point where we don’t want anymore. When you’ve had enough meat and enough salt in the acute setting, you don’t want any more of them, and you might even become actively repulsed by the idea of eating more. (You still like these foods, but you don’t want to eat any more of them at the moment.) But this doesn’t happen with sugar. You can eat and eat and eat, and keep eating. You never really reach a “shutoff” point like you do with salt, fat, and protein. (In fact, even when you’ve reached that point with fatty meat, and you feel like you’d vomit if you had to eat another steak, if someone set a piece of chocolate cake or peach pie in front of you, you could probably find room for a few bites all of a sudden!) I could eat close to an entire package of chocolate chip cookies, and the only reason I’d eventually stop is because I’d be in physical pain or become overwhelmed by self-loathing, or both. But I don’t actually feel satisfied. Not so with salt! When your body needs sodium, salt will taste good to you. But you do eventually reach a point where you don’t need any more in that moment, and salty foods will taste too salty. They will not be desirable to you. The human body is very good at regulating its sodium intake, as Dr. DiNicolantonio emphasizes throughout the book, and bad things—very bad things—happen when we override our natural instincts and intentionally reduce our sodium intake. 

There’s a reason animals go to great lengths to find salt deposits and salt licks, and why ancestral populations made sure to have a steady supply of salt, whether from marine animals and plants and evaporated saltwater, or from a land-based source.

The second thing to know—and hopefully you already do—is that adequate sodium intake is maybe even more important for people on low carb and ketogenic diets. I’ve written about this before: the number one contributor to hypertension is hyperinsulinemia, not salt intake. Insulin influences the way the kidneys reabsorb sodium. Higher insulin leads to greater sodium retention. And there’s a saying in human physiology: “Water follows sodium.” Meaning, if high insulin is causing the kidneys to retain sodium, then more water has to be retained as well, in order to keep the concentration of sodium in the blood at a healthy level. More water in the blood means a greater blood volume, and if we have a greater volume of blood flowing through the same amount of blood vessels, then the pressure goes up—especially if the blood vessels have already been made stiff and unaccommodating due to glycation from constant hyperglycemia. You can see now why a paper Dr. DiNicolantonio co-wrote has one of my favorite titles on this subject: The wrong white crystals: not salt but sugar as aetiological in hypertension and cardiometabolic disease. “The wrong white crystals!” Classic!

(“Hyponatremia,” or too low a blood sodium concentration, can be fatal. It happens during marathons, when people drink too much water without adequate electrolyte replenishment, and also in college fraternity hazing, where idiots convince other idiots to drink ungodly amounts of plain water in a very short amount of time.)

When you are on a low carb or ketogenic diet—and your insulin levels are presumably very low most of the time—you need more sodium in your diet, because your kidneys are inclined to get rid of it. Low salt intake is the kiss of death on a low carb diet. Feeling fatigued, lightheaded, dizzy, getting weaker at the gym, or just plain feeling “blah?” Lots of things could be at work here, but the first and easiest thing to do: GET MORE SALT. You’ll also need a bit more salt if you’re a caffeine junkie, like I am. Diuretic beverages don’t just flush out water; they flush out electrolytes, too. I’ve actually started adding a pinch of salt to my beloved coffee, and I know it sounds weird, but I have to say, it’s delicious.

Hypertension deemed “idiopathic”—meaning, there’s no obvious cause for it—is most often due to chronically elevated insulin, which is why it’s one of the criteria for diagnosing metabolic syndrome (which should be renamed insulin resistance syndrome).  

We’ll get back to issues with sodium, itself, in a sec, but here’s an excerpt that will be of great interest to readers of my blog:

“When you start restricting your salt intake, your body will do anything to try to hold onto it. Unfortunately, one of the body’s defense mechanisms is to increase insulin levels. […] Also, remember that when a person’s intake of dietary salt is on the paltry side, hormones that compensate to help the body retain salt (such as renin, angiotensin, and aldosterone) are released in greater amounts. Well, these hormones end up increasing fat absorption, too. In essence, compared to someone who hasn’t slashed his or her salt intake, a low-salt diet may cause you to absorb twice as much fat for every gram you consume.” (p.91)

Wait, WHAT?

Not eating enough sodium could actually cause higher insulin secretion and weight gain?

It seems so. I have to admit, for someone who’s hyperinsulinemic and obese, increasing dietary sodium wouldn’t be my first recommendation, and I wouldn’t expect it to make much of a dent if this person is still consuming a high carbohydrate diet. We’ve got to cut the carbs first and foremost. But if someone’s already doing a low carb diet and isn’t quite getting the results they were hoping for, it’s possible that adding more salt could get things moving. (Maybe there’s a reason salty stuff like bacon and sausages seem to be so great on low carb diets. It could be our kidneys, rather than our taste buds, that are trying to tell us something, haha!)  

It’s even possible that people with high blood pressure could benefit from more salt, rather than less. A “high” salt intake is rarely the cause of hypertension, but too low a sodium intake can most definitely contribute. Since sodium is so essential for a multitude of biochemical processes, when intake is inadequate, the body will overcompensate in order to ensure it has enough of this most critical electrolyte, and this overcompensation can result in elevated blood pressure. As the quote above says, there are other hormones that get activated when the body needs sodium, and if dietary intake is especially low, these hormones get secreted in higher amounts in order to hang onto every last molecule that is consumed. But holding onto sodium isn’t the only job these hormones have. Just like with insulin, or thyroid hormone, or growth hormone, hormones have multiple jobs, so whatever other things these salt-retaining hormones do will also be done, and be done more, when levels are elevated. So you can suffer whatever unpleasant and potentially harmful effects come from this, or, as Dr. DiNicolantonio suggests, you could use your natural inclinations as a guide and consume plentiful salt, thus sparing your body from having to activate this arsenal of emergency-situation hormones.

DiNicolantonio quotes Robert Heaney, MD, from a paper titled Making Sense of the Science of Sodium: “Demonizing sodium is not only unsupported by evidence but is counterphysiological as well, as it ignores sodium’s most basic function in mammalian bodies.” (p.70) Heany recommends a sodium intake of 3000-5000mg per day. This is far higher than typical U.S. government guidelines and guidelines for those who already have hypertension or T2 diabetes (usually 1500-2300mg/day).

Dr. DiNicolantonio cites data from several populations who consume more sodium than a typical North American intake, and far more than is recommended for people with hypertension, yet these groups have much lower incidence of hypertension and heart disease than we do. Many of them consume more potassium than we do, which is also a factor. (Like calcium & magnesium, and iron, coper & zinc, sometimes problems arise not when we have “too much” or “too little” of them in absolute amounts, but rather, when they’re out of balance with a nutrient they work in concert with. In the case of sodium, it’s potassium.)

So how did we ever come to believe that salt was bad for us? The author provides a nice overview of the history of salt science, complete with closed-minded researchers and government authorities who thought they were doing the right thing. The parallels to the saturated fat and cholesterol stories are so striking that Eric Sodicoff, MD, said The Salt Fix is “like a salty version of The Big Fat Surprise.” Considering what a phenomenal book The Big Fat Surprise is, that is high praise, indeed, and I agree. It turns out much of the salt fearmongering is based on very small studies from a long time ago, and larger and more recent studies have pretty much exonerated salt of crimes against humanity:

“The truth is, a small number of emphatically held assumptions derailed scientific progress for decades—if not generations.” This was accomplished because of “a few researchers’ mistaken assumptions” and “through a lethal combination of inertia, publication bias, and nefarious interests motivated by the food industry…” (p.32)

Ah, yes, Good ol’ inertia. Wrote about that here, with regard to saturated fat.

You know what? Back in the day, I used to buy unsalted pretzels and unsalted fries, thinking I was doing my body good. I felt so self-righteous, kind of like how I bought frozen fries and breaded chicken tenders and baked them in the oven instead of frying them in oil, since that was sooo much healthier! (LOL…I’m sure many of you have similar stories of life before low carb.) Honestly, I’m not a big salt fiend. I enjoy salty foods, yes, but when I ate those unsalted versions, I wasn’t longing for the salt. I didn’t miss it. Maybe I was getting enough sodium from other sources. (Probably the ketchup!)

I’ll end with a quote from this highly recommended book:

“It’s time to set the record straight about the health-protecting, lifesaving nature of salt cravings—and drop the guilt for good.”

  

P.S. I wrote about the salt controversy for my day gig with Designs for Health. You can check it out here: Low Sodium Diets – Are They All They're Cracked Up to Be? (It’s short, I promise!)

Disclaimer: Amy Berger, MS, CNS, NTP, is not a physician and Tuit Nutrition, LLC, is not a medical practice. The information contained on this site is not intended to diagnose, treat, cure, or prevent any medical condition and is not to be used as a substitute for the care and guidance of a physician. Links in this post and all others may direct you to amazon.com, where I will receive a small amount of the purchase price of any items you buy through my affiliate links.