11 Key Benefits of Salt (& Pitfalls of Consuming Too Little) w Dr. James DiNicolantonio DPharm

The cure for anything is salt water, sweat, tears, or the sea. Can you speak a little bit to that evolutionary connection to salt? Yeah, no, that's a great quote, and it speaks volumes for what the book is going to cover and how important salt is and how we really are basically walking oceans, right? We carry this saltiness within us in our blood. And so really, the concentration of salt compared to other minerals in our blood is the exact same as the ocean. 90% of the minerals in our blood is sodium and chloride. And so those are the two main electrolytes in our blood. And our body control salt intake because it is an essential nutrient and because the levels in the blood determine not only the hydration of our cells, but how fast our heart rate works. And without salt, literally, we would perish. So that internal sea and that we carry the saltiness and that if we lose it, we're at risk of all these harms, is really the essence of what my book is, making sure we're maintaining that salty sea, replacing what we're losing throughout the day. That's very well said. And, you know, in the book, you discuss the diets of hunter gatherer populations, you know, from 2.6 million years ago to about 10,000. And of course, the research traditionally estimates lower salt intakes. Now, is this correct or is there more to the story? Yeah, no, it's a great question. And so I kind of go back in time to the main New England Journal of Medicine paper from the fathers of the Paleo diet. It was Eaton and Boyd published a paper, and really, this is where all of us think that evolutionarily we consumed a low salt diet. They estimated that on a vegetarian diet, we would only consume about 400 milligrams of sodium. And even on a full meat diet, we would only get about 1400 milligrams of sodium, which is just over a half a teaspoon of salt. The problem is they only looked at muscle meat, even though we consumed the entire animal, the salty blood, the salty interstitial fluid, the salty organs. So they inappropriately basically downgraded how much salt we would get during those 2.6 million years, because one deer contains 30 days worth of a normal salt diet today. And so we know that, yeah, when you put it like that, people can start to understand that from an evolutionary perspective, we probably consumed a high salt diet. And even for the last 10,000 years, the main food preservative was salt. And so we used to consume up to 10 times as much salt for the last 10, 10,000 years or so compared to what we do to today, now that we have a refrigerator and we don't need to lace all our food with salt to preserve it. Yeah, and I mean, that's some phenomenal insights. And you know, if we take a step back before we dive a little bit deeper here and perhaps give listeners a quick review of, you know, what does salt do in the body and why do we need salt? Yeah, that's a really great question. And in the book, I really wanted people to understand the benefits of salt. So let's take salt and let's just kind of break it down into what it really is. Salt is two essential micronutrients, sodium and chloride. Most people don't know that chloride is actually what makes up hydrochloric acid. So if you want to be able to digest food, absorb nutrients from your diet, prevent bacterial overgrowth, you need to consume salt because that's the chloride. We'd be here for. We would be here, yeah, we'd be here for probably an entire year. But basically, if you want to absorb water soluble vitamins like vitamin C and biotin, you need sodium. Sodium helps keep our heart rates low. It gives us a blood volume. We demonize blood pressure, but we need a blood pressure, right? We need blood circulation and sodium brings us good blood circulation. And a lot of people suffer from dizziness and hypotension and really increases in heart rate, which is called pots. Postural orthostatic tachycardia syndrome. A lot of females suffer from this syndrome where when they go from a seated to a standing position too quickly, they have an over 30 beat per minute increase in heart rate. Salt is one of your best ways to fix that situation. So salt gives us blood pressure, gives us blood circulation. It actually allows vitamin C to get into the bones in the brain. So salt has all these really important properties. It allows the heart to beat, it allows nerves to communicate with each other. It allows potassium to come in and out of the cell, which also allows calcium to come in and out of the cell. And it allows glucose to come in and out of the cell and probably almost. It also allows hydrogen to come in and out of the cell in other molecules. So really, if you want anything, almost anything, to go in and out of the cell in some way, sodium is an important driver of that because it drives basically the transgradient, that energy potential between the inside and the outside of all of our cells. Yeah, it's phenomenal. I mean, in the book you give a thorough treatment to all the important functions there. And it really is mind blowing when we see just how essential obviously this is. Now, where did we, you know, where do these low salt recommendations come from? How do we get to this point? Yeah, that's really the first question I wanted to answer in the salt fix was where did we get this idea that salt an essential mineral, that our body controls its intake. We would want to consciously restrict it to what certain guidelines are telling us to as if they're smarter than our own bodies. And so really I go through this over hundred year history of where the salt blood pressure hypothesis comes from. And it starts out in 1904 with two French scientists named Ambard and Bozard. They gave 20 grams of salt to just six of their patients and they saw trends in blood pressure go up. And then when they cut the salt intake, it went down. And three years later another scientist said, well, he didn't really find those findings. So that was the beginning of the salt wars, what I like to coin that term, the salt wars. So it started literally in the early 1900s. That's how far this goes back. But in regards to where did this get into a recommendation for all Americans? It stems from the 1977 dietary goals where we're dealing with all our nutritional whiplash from those 1977 dietary goals. Right. They told us to eat a high carb diet, they told us to cut fat, they told us to cut salt. So that's where it comes from. And they really based those recommendations. They misrepresented what two experts at the time were trying to say. So George Maneeally and Harold Botterby were the two main scientists. They came out with a review paper the year before the 1977 dietary goals were published and they were called upon as Experts for George McGovern's Senate Select Committee. But their paper, actually I looked it up, downloaded it, read the whole paper, it is an excellent paper. It was just a hypothesis. And what they said was, is that only if you consume a low amount of dietary potassium and only if you are one of those minority who is genetically susceptible to salt's blood pressure raising effects, should salt be restricted. But of course those nuances did not get into the 1977 Dietary Goals when they told all Americans to cut their salt intake. Yeah, it's amazing how nuances seem to get lost along the way. Of course in your book you talk about traditional diets and of course there the average sodium intake of traditional diets versus those recommendations. Can you touch on that? Yeah. What I try to go back to time and again is when you look at the longest living people in the world, the Japanese, the South Korean, even the Mediterranean cultures which consume a high salt diet, these populations consume a very high salt diet. So even from a population level, if you look at it, why would you ever want to go and consume a low amount of salt? We don't know any populations that live very long that consume minimal amounts of salt to live. So from that perspective, if you look at those cultures that live long consuming salt, they're not consuming processed foods, which provides most of the salt. They're eating real food and salting to taste. So South Koreans eat a lot of salty kimchi and miso soup. So they're eating basically fermented vegetables and they're fermenting their vegetables in salt. And we know that Japanese eat a lot of seaweed and they eat a lot of seafood. So if you can kind of incorporate those into types of foods and incorporate salt into real food, it doesn't seem to be an issue. In fact, it seems to be a longevity factor. Low salt diets being commonly prescribed by doctors, and of course blood pressure being at the foremost for the primary interventions is to tell patients to reduce salt. So where does the evidence actually stand on that and what's the trend been since the 1950s in terms of hypertension in the general public? Yeah, that's a great question mark. So what ended up happening is the hypertension guidelines in the United States relied on the first meta analysis of low salt diets and blood pressure, published in 1991. So that goes to show you, we didn't even have any meta analyses on blood pressure until almost 15 years after we had already demonized salt. Wow. Wow. But what they did was is that meta analysis was 90% non randomized studies. And so it showed about a 10 over 5 millimeter per mercury reduction when you cut your salt intake by a full teaspoon. The problem is, two years later, a meta analysis only on randomized trials showed that that benefit had been over exaggerated by tenfold on systolic and by 50 fold on diastolic. So all we really saw was about 1 millimeter per mercury reduction in blood pressure when people with normal blood pressure cut their salt intake and only a 0.1 millimeter per mercury reduction in blood pressure on diastolic. But the problem was is the hypertension guidelines relied on the weakest evidence at the time, which overestimated, dramatically overestimated, the blood pressure lowering effects of salt. So again, what I will always tell people, if you have normal blood pressure, you're Talking about a 1 point reduction on systolic and your trade off is about a 4 to 5 beat per minute increase in heart rate. And I will let you decide what is more harmful.