 I'm often asked what my opinion about a diet or disease is. Who cares what my or anyone else's opinion is? All we should care about is what the science says. What does the best available balance of evidence published in the peer-reviewed medical literature have to say right now? Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. Today, we examine the need for less sodium and more potassium-rich foods. Did you know that staggering 99.99% of Americans fail to meet the minimum-recommended potassium or the maximum-recommended sodium? Here's the story. Worldwide, physical inactivity accounted for more than 10 million years of healthy life lost. But what we eat accounts for nearly 20 times that. A unhealthy diet shaped hundreds of millions of disability-free years off of people's lives every year. What are the worst aspects of our diets? Four out of the five of the deadliest dietary traps involve not eating enough of certain foods, not eating enough whole grains, not eating enough fruits, not eating enough nuts and seeds, and not eating enough vegetables. But our most fatal flaw is too much salt. That's on the order of 15 times deadlier than diets too high in soda, for example, just to keep things in perspective. There remains no single more effective public health action related to nutrition than the reduction of sodium in the diet. This is why national and international health organizations have called for warning labels on salt packets and salt shakers with messages like, you know, too much sodium in the diet causes high blood pressure and increases risk of stomach cancer, stroke, heart disease, and kidney disease limit your use. It also increases inflammation. For example, sodium intake is associated with increased disease activity in multiple sclerosis, an inflammatory autoimmune nerve condition. About three to four times the exact serbation rate in those with medium or high sodium intakes compared to those getting less than a teaspoon of salt total in a day. Just as you can see, higher sodium levels in the tissues of those who suffer from lupus and other serious inflammatory autoimmune disease, you can correlate high sodium levels in the spinal cord of MS patients with the disease and decreased structural integrity. Where is sodium found, though? Really crappy food, so it's hard to know if increased salt intake is just a marker for a bad diet overall. But what we do know is that salt and high blood pressure are cause and effect, how? Because we have more than 100 randomized controlled trials demonstrating that if you cut down on added salt, your blood pressures fall, and the more you cut down, the better. Part of the mechanism may actually be the damage salt may do to your microbiome, the friendly flora in your gut, and no wonder. Our bodies evolved only to handle about 750 mg a day. The American Heart Association says we should stay under at least twice that about, but we're eating more than four times what's natural, and it's only getting worse, increasing over the last decade. Anyone care to guess what percentage of Americans exceed the 1,500 mg upper limit recommendation? 98.8%, and that was more than a decade ago. The vast majority of U.S. adults consume too much sodium, and at the same time, too little potassium, a mineral that lowers blood pressure. Less than 2% of U.S. adults consume the recommended daily minimum intake of potassium. So more than 98% of Americans eat potassium-deficient diets. This deficiency is even more striking when comparing our current intake with that of our ancestors, who consumed large amounts of dietary potassium. We evolved getting probably more than 10,000 mg a day. The recommendation is to get around at least half that, yet most of us don't even come anywhere close. Put the two guidelines together, and sodium and potassium goals are currently met by less than 0.015% of the U.S. population. Since we're talking close to 99.99% non-compliance, as in only 1 in 6,000 Americans even hits the recommended guidelines. What about using potassium-based salt substitutes? Instead of using sodium chloride salt, why not shake on some potassium chloride? Seems a little too good to be true. I mean, same salty taste, but you're reducing sodium, while at the same time increasing your potassium intake? Is there a catch? Are potassium-based salt substitutes safe, effective? We'll find out next. Of all the terrible things about our diets, high dietary sodium intake, high salt intake, is the leading risk, estimated to be causing millions of deaths every year, killing millions mainly through adverse effects on blood pressure, an increased risk of stroke, heart attack, and kidney damage. High pretension, high blood pressure is still called the silent and invisible killer, because it really causes symptoms, but is one of the most powerful independent predictors of some of our leading causes of death. We evolved consuming a diet very rich in potassium and low in sodium, but today this pattern has been completely reversed. This flip reflects a shift from traditional plant-based diets, high in potassium and low in sodium, a shift from fruits, greens, roots, and tubers to salty processed foods stripped of potassium, which is considered a nutrient of public health concern, because 98% of the US population doesn't even reach the recommended minimum daily intake of potassium, as I mentioned in the last video. And low potassium intake itself is implicated in high blood pressure and cardiovascular disease, yet few physicians actually think about proposing their patients eat more foods that are potassium rich, like fruits and vegetables, to better control blood pressure. Even though several meta-analyses have now confirmed that high potassium intake appears to reduce the risk of stroke. There's even a reduction in stroke risk independent of blood pressure effects, consistent with other protective effects of potassium, such as reducing clot formation, reducing the hardening of the arteries, reducing the generation of free radicals. Higher sodium intake is associated with a 20% increased risk of dying prematurely, where higher potassium intake was associated with a 20% reduced risk of dying prematurely. Yeah, but sodium is found in crappy processed foods, while potassium is concentrated in healthy foods like beans and greens, so having a low sodium intake and high potassium intake may just be a marker for a more healthful diet and more plant foods and less crap. How do we know sodium has caused an effect bad? Because randomized controlled trials show sodium reduction leads to blood pressure reduction, just like their randomized controlled trials, showing that if you give people extra potassium, you can bring down their blood pressures as well. So what about using potassium chloride to salt your food rather than sodium chloride? That's what's found in the zero sodium salt substitutes. Potassium chloride is a naturally occurring mineral salt, which is obtained the same way we get regular sodium salt. Since we get too much sodium and not enough potassium, this would seem to make potassium chloride a win-win solution. Now, whole healthy plant foods would be the best way to increase potassium intake. Fruits and vegetables have all sorts of other good things in them besides potassium, but we have 10 studies now, randomized controlled trials, showing that just swapping in some potassium chloride for regular salt can lead to significant reductions in blood pressure in people with hypertension, suggesting that salt substitutes may even help prevent hypertension as well. We know salt substitutes can lower blood pressure, but does it actually decrease the incidence of hypertension? And more importantly, disease endpoints like stroke and mortality? You don't know until you put it to the test. In a randomized controlled trial, households had their salt replaced with just a quarter potassium chloride. At that level, most people either can't tell the difference or even prefer the salt with the potassium mixed in. Okay, but did it actually do any good? The use of even the quarter salt substitute was associated with cutting the risk of developing hypertension in half. Okay, but what about actually following people out to see if there's any change in the risk of dying from cardiovascular disease? Five kitchens in a veteran's retirement home were randomized into two groups. For about two and a half years, salting meals with regular salt or, unbeknownst to the cooks and the diners, a 50-50 blend of potassium chloride. Those in the half potassium group cut the risk of dying from cardiovascular disease by about 40% and lived up to nearly a year longer. The life expectancy difference at age 70 was equivalent to that which would have naturally occurred in 14 years, meaning that just switching to half potassium salt appeared to effectively make people more than a decade younger when it came to risk of death. As we speak, there's a massive randomized controlled trial wrapping up in China involving 600 villages and more than 20,000 people that'll give us an idea of just how low we can drop stroke risk with this strategy. China is perfect because up to 75% of their sodium intake comes from salt they add in the home kitchen or dining room, whereas most sodium in the American diet comes prepackaged in the meat and processed foods we buy. Those certainly the food companies could switch over themselves. Why haven't they? And why haven't more people embrace these salt substitutes if they work well and can taste just as good? We could be achieving the benefits of a high potassium paleolithic diet without the toxicity. So is salt substitution ready for prime time or what? What about safety? Yes, there are convincing arguments about the benefits, but what about the risks? Like, you know, the quote-unquote inclusion of potentially fatal salt substitutes in the food supply? Wait, what? We'll talk about the potential downsides next. Based on how we evolve, the optimum dietary potassium intake likely greatly exceeds current and even recommended intakes. The problem is we replace many of the potassium rich plant foods we used to stuff our faces with like fruits, leafy greens, and other vegetables, including roots and tubers, with calorie-dense junk stripped not only of fiber, but also potassium, such as added fats and sugars. So when a traditional largely plant-based diet, potassium content is high and sodium content is low, but now high blood pressure is the second leading cause of death in the world, killing more than 10 million people a year, second only to unhealthy diets, the number one killer of humanity. We can improve both by eating more whole healthy plant foods like beans and greens which are packed with potassium, which lowers blood pressure. But since most of us are getting too much sodium along with too little potassium, what about using salt substitutes? After all, the most commonly used salt substitute is potassium chloride, so you'd be swapping out sodium for potassium. And it works, based on a meta-analysis more than that does in randomized controlled trials, replacing sodium chloride with potassium chloride lowers blood pressure. And most of the trials involve just swapping out regular salt for less than 30% potassium chloride and they still got results. And at less than 30%, most people can't even tell the difference between regular salt and the potassium salt. So we can taste exactly the same and drop your blood pressures? What's the catch? Potassium chloride is generally considered to be safe by the FDA, with the only major concern for healthy people, being that if you go completely 100% sodium-free and use straight potassium chloride, it can taste kind of funny, adding a bitter or metallic taste. I've found that it depends on what I'm seasoning with it. It works perfectly well on some things, but makes other things completely inedible. When I learned about the sodium science and threw out my salt shaker for good, within a few weeks my palate totally changed and everything tasted fine without salt, except pesto. For some reason, pesto without salt just never tasted like it used to to me. So I tried the potassium chloride salt substitute and it worked perfectly. I couldn't tell the difference at all, so I had the best of both worlds. Then I remembered how as a kid, I used to put a tiny sprinkle of salt on watermelon like they do in the south to make it even sweeter. So I tried it with potassium salt and almost gagged. So it's definitely not for everything. The recent healthy people don't have to worry about getting too much potassium. Instead, our kidneys just pee out the excess. Okay, but that's with potassium in food. What about supplements? No adverse effects have been shown for long-term intakes of potassium supplements as high as 3,000 milligrams a day. In fact, blood levels of potassium are maintained in the normal range by healthy kidneys, even when potassium intake is increased to approximately 15,000 milligrams a day, which is no surprise since we evolved the eating so many healthy plant foods, so many fruits and vegetables that the normal natural potassium intake for the human species may be on the order of 15,000 milligrams a day. Basically, the normal range for potassium levels in the blood is between 3.5 and 5, and you start to worry when it starts creeping up towards 6, but give people potassium supplements like all the salt substitution trials that have been giving study subjects an average of about 2,000 milligrams of potassium a day, and blood levels only go up 0.14, so they might go up from 4 to 4.14, not something that would push you into trouble. Now, there's a limit. If you have a quote-unquote massive banana eating habit, you could bump your potassium from normal to above 6, but that was evidently from years of not eating much of anything, except up to 20 bananas a day. Eating 10 pounds of carrots every day is also probably not a good idea. That's like 75 carrots in one day. What about overdoing salt substitutes? This report from the 1940s was on lithium poisoning from the use of salt substitutes. Why? Because lithium chloride was used as a salt substitute. Jesus! But what about potassium chloride, which is what's used today? There is one fatal case of someone who committed suicide by downing a little more than a tablespoon of potassium chloride salt substitute. That doesn't seem like a lot. Just a tablespoon? I mean, how can we keep that on the shelves if only a tablespoon will kill you? Well, even less than that of regular salt taken at once can kill you, too. In fact, salt water ingestion was evidently a traditional method of suicide in ancient China, though these days one may be more likely to die that way from abusive religious practices. Having said all that, there are a small number of the population who may run into problems, primarily those with severely impaired kidney function. That's why there's been such a reluctance to push potassium-based salt substitutes on a population level. If your kidneys can't regulate your potassium, then you can definitely run into a serious issue. And we're talking about folks with known kidney disease, diabetes, since diabetes can lead to kidney damage, severe heart failure, those on medications that impair potassium excretion, older adults, and individuals with adrenal insufficiency. If you aren't sure, if you're at risk, ask your doctor about getting your kidney function tested. Ironically, potassium is so good at reducing deaths from high blood pressure, even among those with kidney disease using potassium chloride salt substitutes would probably still save more lives despite the risk. Traditional dietary recommendations to kidney patients limited the intake of fruits and vegetables because of their high potassium content. However, this paradigm is rapidly changing due to the multiple benefits derived from a fundamentally plant-based diet. A whole-food plant-based diet may even ameliorate chronic kidney disease. There's increasing evidence that a whole-food plant-based diet may offer benefits like slowing the progression of chronic kidney disease and delaying kidney failure. So the practice of restricting dietary potassium in kidney patients should really be reserved for patients with documented hyperkalemia, a potassium level of 6 or higher, because the key to halting the progression of chronic kidney disease may in fact lie in the produce aisle. 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