Modern medicine has many sacred cows, but few are as highly revered as the belief that a high salt intake leads to high blood pressure. In his new book The Salt Fix, Dr. James DiNicolantonio tries not only to slaughter this sacred cow, but to grind it up and make salty burgers out of the carcass.
The equation of high salt consumption = high blood pressure is so ingrained in our views about diet and health that to question it is to instantly be labeled a fool, a shill for Big Salt, or worse. According to Dr. DiNicolantonio, we’ve been demonizing the wrong white crystal the whole time by overlooking the essential role salt plays in our biology while ignoring the many ways sugar is killing us.
I’ve listened to the audiobook version and experimented with a high salt diet for six weeks. Read on to find out how it went.
I bought the unabridged audiobook version of The Salt Fix so I could listen to it on my daily commute. The book came on a single disc of MP3s, which I much prefer over multiple CDs. It was really easy to import the content into my computer for transfer to my phone, and I’ve listened to the entire book twice.
Over the course of eight chapters and five hours of audio, Dr. DiNicolantonio lays out the case for why salt has unfairly been cast as a dietary villain and explains why we should be paying more attention to the unhealthy effects of sugar instead.
There are also three appendices and a Notes section that includes citations for every study referenced in the book.
If you buy the audiobook version, be aware that the Notes section with the citations is not included. I’m guessing this is because it would be extremely boring and expensive to have someone narrate every single reference, but considering how controversial the topic of this book is, I think the references need to be made available as a downloadable PDF.
I had to reach out to the publisher to get a copy, but they were very helpful and sent me a PDF with the missing citations.
I think it’s fairly common knowledge that salt was highly valued in ancient times, much more so than today. What’s not common knowledge is that a war has been quietly raging in medical circles for over 100 years on whether or not salt has a legitimate place in a modern healthy diet.
Broadly speaking, the contents of The Salt Fix fall into five main topics:
The Salt Fix is well written and engaging, and the evidence presented was convincing enough for me to experiment with increasing my own salt consumption and measuring my blood pressure every day for six weeks. I discuss the experiment and results further down in this article.
Dr. DiNicolantonio does a great job of explaining how and why the body self-regulates sodium content. Sodium is a necessary element for proper blood volume, and the body is very good at regulating how much sodium it retains.
Consume too much salt and your kidneys will just excrete it in urine. Too little, and your body will trigger several biological systems to retain it, including constricting blood vessels to compensate for lower blood volume.
Yes, you read that right – a lower salt intake could result in increased blood pressure, which is exactly the opposite of what mainstream medicine keeps telling us.
Through listening to this book, I learned that a healthy pair of kidneys can easily process up to ten times the amount of salt that the typical American consumes on a daily basis. That’s a lot of salt!
Salt isn’t inherently evil – it makes vegetables and other natural foods taste better, and you need it to stay alive. I know first hand from experimenting with a whole food plant-based diet that salt makes sticking to an otherwise bland diet much easier.
In The Salt Fix, Dr. DiNicolantonio makes a convincing case for a drastic reduction and even complete elimination of excess sugar from a diet. Hypertension and obesity have gone up at nearly the same rate as sugar consumption, while the amount of salt added to pre-packaged food has been on a steady decline for years.
The sugar connection makes sense if you think about our current attitudes toward sugar. Sugar is added to practically everything that comes pre-packaged these days – sodas, breads, pastas, frozen meals, chips, candy bars…the list goes on and on.
Even “healthy” options like sports drinks and protein bars have sugar added to them for taste.
Contrast this to the amount of salt that gets added to pre-packaged foods. Look at any food nutrition label, and you’ll see that sodium is measured in milligrams, while sugar is measured in grams.
In other words, as a society we are fine with potentially consuming ten times more sugar than salt!
Sugar is killing us and we’re okay with that because it tastes good and we’re addicted to the dopamine hit. Obesity and hypertension are at epidemic levels, and even our children are being diagnosed with hypertension and heart disease at very young ages.
This madness has to stop. A sugar addition can be overcome, it just takes discipline and time. I’ve done this myself, so I’m not blowing smoke. If I can do it, so can you.
Although engaging and convincing, The Salt Fix doesn’t quite deliver the knockout blow needed to dispel the myth linking hypertension to salt consumption. Even though this book changed my mind about salt consumption, there were portions I found unconvincing or confusing. Others are likely to hit the same sticking points, so I’ll elaborate.
In my opinion, the chapter on our evolutionary need for salt relies entirely too much on speculation of what the diets of our ancient ancestors might have been like, which is impossible to prove one way or the other.
Thankfully, the evolutionary angle is just one of several arguments in favor of salt, but it’s by far the weakest.
Another nit I need to pick is with conflicting interpretations of major studies like INTERSALT, which is cited in the book as proving that salt consumption is not linked to hypertension even though the study itself does assert there is a link between the two.
This particular discrepancy is addressed by Dr. DiNicolantonio in the Q&A section at the end of this article.
On the topic of studies, numerous studies have been done that demonstrate a link between hypertension and salt consumption.
Numerous studies have also been done that show no link between hypertension and salt consumption.
As a result, it’s difficult to know who to believe. One point on this topic that is made in the book and in the Q&A with Dr. DiNicolantonio is with regards to what these studies measure versus what they don’t.
In many cases, the effects attributed to increased salt intake do not measure sugar consumption, so it’s very possible the effects are attributed to the wrong white crystal.
In other cases, adverse side effects to a low salt diet are not recorded, so we only get one side of the story.
My advice is to take the recommendations with a grain of salt (see what I did there?) and experiment for yourself. Speaking of which…
I first heard Dr. DiNicolantonio’s views on salt during an interview he did with the hosts of a podcast focused on the ketogenic diet. I was intrigued enough to buy the book, and I decided to experiment with increasing my own salt consumption to put the claims he made to the test.
I bought The Salt Fix audiobook along with a blood pressure monitor and resolved to eat as much salt as I wanted for six weeks. During those six weeks, I heavily salted all my foods and often consumed salt raw, especially before and after exercising.
I measured my blood pressure for seven days prior to changing my salt intake to get a baseline blood pressure measurement. After obtaining the baseline, I increased my daily salt intake and measured my blood pressure every day as soon as I woke up.
I increased my salt consumption by roughly 3x and measured my blood pressure for six weeks. I didn’t measure the exact amounts of salt I was eating every day, but I can tell you that I ate a lot of salt. I heavily salted everything, at practically every meal.
I went on a vacation outside the country for ten days toward the end of July through the beginning of August, so I didn’t measure my blood pressure those days. However, I still maintained my increased salt consumption.
Over the course of those six weeks I saw no corresponding increase in my blood pressure levels:
Blood pressure fluctuates on a daily basis, which is normal. If high salt consumption is indeed a causative factor for high blood pressure, I would expect to see a noticeable upward trend in the results. As can be seen from the graph, I only experienced normal fluctuation and no discernible variance from the baseline measurements.
I also noted a decreased desire for sugar. I usually keep some dark chocolate bars handy for those times when I do crave something sweet, but I found that the craving rarely came.
I mentioned consuming salt before and after workouts. The extra sodium helped me maintain my endurance during kettlebell and barbell workouts, and it helped with recovery as well since I didn’t feel as fatigued as I normally do after a workout.
The Salt Fix is an interesting book, and like many books on controversial topics, it’s probably going to be a polarizing one.
Depending on how much faith you have in the medical establishment, you may be extremely skeptical of the claims made or find yourself nodding along in agreement with every page. I don’t think there’s much of a middle ground on this one.
Personally, I fall on the skeptical side of the medical divide, especially in this day and age when even basic research can’t be trusted due to agendas and undisclosed conflicts of interest that influence results. I’m not saying this always happens, but it happens often enough to make separating fact from fiction very difficult.
My view is that any claim made regarding diet should hold up under personal experimentation and observation. I’ve put the claims made in The Salt Fix to the test by increasing my salt intake and measuring my blood pressure, and I’ve found that the claims do hold up.
Salt consumption alone does not account for the epidemic rise of hypertension around the world, and it’s time to stop demonizing salt.
As a society, we do need to start paying more attention to sugar and how bad it is for our health. Luckily, you as an individual don’t need to wait for modern medicine to get around to telling you that your sugar intake is what’s really killing you.
Or do you?
Q. Much of the reading I did on the topic of salt consumption implied or flatly stated that anyone who denies the connection between salt and hypertension has ties to Big Salt. For the sake of transparency, do you have any ties to the salt industry to disclose?
A. No I do not have any conflicts to disclose.
Q. In The Salt Fix, you discuss several physiological signs that indicate an individual needs more salt. Are there similar physiological signs that indicate an individual has consumed too much salt? If so, what are they?
A. Your salt taste receptors will flip and salty foods will taste too satly. Also, even if we consume more than we need the kidneys will simply get rid of any salt the body doesn’t need.
Q. INTERSALT is often cited in many studies as proof of the connection between salt consumption and hypertension. You cite INTERSALT in The Salt Fix as well, but as proof that salt consumption is not connected to hypertension.
I’ve read the study, and I do see that the conclusions drawn from the study are much weaker when the 4 primitive societies with extremely low salt intake are excluded from the analysis. From the abstract:
Across the other 48 centers sodium was significantly related to the slope of blood pressure with age but not to median blood pressure or prevalence of high blood pressure.
How can the results of such a widely cited study be interpreted two ways? Are there flaws in the methodology and/or protocol that are glossed over?
A. You can slice and dice data and look at the data to come to different conclusions. Also, not reporting data that can make low-salt diets look bad. Heart rate is another way to affect how the results of INTERSALT are reported, if you measure heart rate but don’t report on the effects then we can’t glimpse the full picture. Bjorn Folkow claimed that INTERSALT did measure heart rate but they never reported the data. Almost every study shows that low-salt diets significantly increase heart rate (an effect much greater than the blood pressure reduction on a low-salt diet). So by not reporting heart rate obviously this would bias the results in favor of low-salt intakes.
Q. The chapter on evolution got me thinking about whether or not any studies had been done on salt consumption and blood pressure of our closest living primate relates, i.e. chimps and bonobos. I did some Googling and found a study done in 1995 that did just that. Are you familiar with this study? What’s your take on the results and the conclusions drawn from it?
A. The studies looking at blood pressure in chimps give the chimps very high amounts of salt. And those studies don’t use salt to dramatically improve the overall diet like can happen in the real world in humans. In other words, salt allows people to eat real whole foods, whereas chimps are given the same poor diet but one with a huge amount of salt added to it and one lacking salt. Most studies show that a normal salt diet does not affect the blood pressure of chimps and that you need to give them 2-4 times a normal salt intake to see any clinically meaningful increases in blood pressure.
We know in humans salt doesn’t have that big of an impact on blood pressure as 80% of people with normal blood pressure aren’t salt-sensitive and even in those with hypertension only about 45% are salt-sensitive (again even in people who have large reductions in blood pressure this can be volume depletion/dehydration and is a bad thing).
We know humans aren’t chimps. Humans consumed more animal foods during evolution (and thus a higher salt intake than chimps). The chimp studies show that big increases in blood pressure don’t really occur until you add about 15 grams of salt to their diet (and remember chimps are much smaller than humans). Also the increase in blood pressure were much larger in the chimps that already had high blood pressure and not as big in those that had normal blood pressure.
For example, in the paper by Elliot P, Change in Salt Intake Affects Blood Pressure in Chimps, 43% of chimps had hypertension at baseline and hypertensive humans are more sensitive to salt but its not the salt per se, normally they are salt sensitive due to the insulin resistance caused by overconsuming high amounts of refined carbs/sugar. Cut the refined carbs/sugar and you can normally fix the “salt-sensitive” blood pressure.
I'm a software product manager with a full-time job, family, and a desire to stay strong, mobile, and fit. I separate fact from fiction to find the most effective and affordable options for home fitness. If you'd like to build your own home gym, start here.