For people with kidney disease, protein intake is a key issue, yet it is often surrounded by misunderstandings. This video explains in clear terms why excessive animal protein can strain the kidneys, how this is connected to hyperfiltration, insulin resistance, the state of the gut microbiome, and inflammatory processes, and why plant-based protein sources are often a better choice.
We review the most important scientific links, practical dietary guidelines, and also discuss when the kidneys become so overburdened that kidney replacement therapy is needed. The goal is to make one thing clear: protein itself is neither “good” nor “bad”—it’s the balance that matters.
The content of the video in written form
Hello, this is Dr. Zsom. Dear patient!
Well, today we’re going to talk about a very important topic, namely when you have kidney failure of any kind, you will sooner or later hear about protein and protein restriction. And we need to make sure that we understand what we are talking about, or else things can go very spectacularly wrong if we don’t understand what this actually means and entails.
So in the initial stages of kidney disease, reducing protein intake, provided that protein intake was excessive, will certainly benefit the kidneys. Why is that? Because too much protein, especially animal-based protein, will cause hyperfiltration. So the kidney will overwork, and the more the kidney overworks, the more the chance that the kidney is going to fail.
So remember, our ancestors worldwide worked more in the fields than us and ate far less animal protein than us. And so what that means is that the human body, for centuries, for millennia, is used to a certain kind of diet, and we changed that. Not only that we eat much more meat, but much of this meat is actually processed. Now compare that to what happened to the Roman gladiators, who are known to be physically fit. They lived primarily on beans. And this is a historical fact. So the Fabius clan was named after beans, because obviously these were bean producers. Beans were a big thing in Rome, even though they really had to exercise quite a bit.
So what I’m saying here is that eating too much meat, and by shifting the balance from plant-based protein diet to animal-based protein diet primarily, is something unnatural. So I remember in my own practice in Louisiana that there were these young, healthy people who wanted to donate their kidneys as a charity. And so, of course, they went to the steakhouse every day and they ate large portions of steaks. So we evaluate these people, and lo and behold, we have hyperfiltration and proteinuria, which comes together with hyperfiltration. In other words, if the kidney is overworked, then protein in the urine is very common, and even without diabetes, these people behave as if they had diabetes.
So what is happening here? Well, scientific research picks out something, generalizes that something, and then seeks correlation between that something and certain outcomes. So scientific research initially did not make the differentiation between plant-based protein and animal-based protein, let alone their optimal ratio. So now what happens is that many doctors and nurses and dietitians, they learned at the university that if you reduce protein, that will create good outcomes. And here, like in so many other instances in modern life, quantity is regarded as all-important, and quality is disregarded.
So we are not saying here that animal protein is not healthy, but it is unhealthy in excess, and it is unhealthy if the balance between animal protein and plant-based protein is overwhelmingly in the favor of animal-based protein. So why is this so? Because that’s what we learned at school. And then later on, scientific research comes along that happens to totally conform to common sense. We know that if you eat too much animal protein, that will lead to proliferation of certain bacteria in the gut, and those will produce a lot of poisons, toxins. And they disturb the barrier between the gut and the circulation. Whereas if you eat plant-based protein that has fiber, fiber restores this balance and protects this epithelial barrier between the gut flora and the circulation, not to mention that there are other issues that this fiber is going to help, which we’re going to detail in the next few slides.
So first of all, what did we say about Louisiana? We said that in our practice, we saw these patients, with excess, not patients, healthy people, with excessive animal protein intake. And what did they have? They had insulin resistance without diabetes. Now, plant-based dietary patterns do not cause this. And so, like in diabetic kidney disease with enhanced animal protein, even without diabetes, you have overwork of the kidney, protein in the urine, and decreased kidney function later on. So if you eat a steak, your kidney function is going to go high, and then you’re going to exhaust your kidney. But of course, that is partly masked by the fact that meat has creatinine in it, and so your creatinine goes up as if your kidney function was actually lower, because remember, eGFR is based on creatinine, which is in, what, in meat.
So basically, what happens is that when you eat a lot of animal meat, your lab work becomes unreliable, not to mention the bad impact that it has on circulation and kidney. Now, in the case of plant-based diets, these things do not happen, especially if these are natural grains or natural protein sources. So what happens here is that there is no insulin resistance and there’s no overwork on the kidney unless you eat extreme amounts.
So in terms of chronic kidney disease, when you already developed chronic kidney disease, then they tell you that you have to eat meat because essential amino acids that the human organism cannot produce by itself are in meat. But now we know that this is not entirely true, because if you eat a well-balanced diet, then you do not need meat, and definitely not a lot of meat, to have these essential amino acids on board. In terms of iron, in terms of zinc, there are also plant-based sources now.
So what is the downside of too much excessive animal protein in terms of side effects? Now, saturated fatty acids and cholesterol, they of course hurt the blood vessel walls. Sorry, let’s go back. So also reactive oxygen species that also come from animal intake, animal protein intake, can cause inflammation in blood vessels. These uremic toxins that are produced in the gut also cause inflammation. What else causes inflammation? Salt. Salt, which comes from, you know, as salt is a meat preservative. So salt, which comes from meat also. So all of these cause inflammation in blood vessels, and of course blood vessels are also in the kidney. Phosphorus can also cause damage in blood vessel walls. So all these downsides come from excessive animal protein intake. And so glomerular hyperfiltration, in other words overwork of the kidney, raised sodium intake causes systemic hypertension. But we also know that systemic hypertension, behind systemic hypertension, there is blood vessel inflammation. So hypertension, high blood pressure, is a symptom of inflammation, and what do we want to prevent? Inflammation. Not to mention all the organic acids that get produced, not from plant proteins, but from animal proteins. And besides kidney stones, they can also damage the blood vessel walls.
So the National Kidney Foundation came out with a statement, available here, that eating more plant-based foods such as vegetables and grains in place of animal-based foods such as red meat may help prevent and slow down progression of chronic kidney disease, type 2 diabetes, high blood pressure, and heart disease. Why is that? Because we prevent what? Inflammation of the blood vessels and overwork of the kidneys. And so if you want to dig deeper, here is a doctor who very often writes very good articles about the association of diet and kidney disease. And so what he is saying is that plant-based diets should be recommended for both primary and secondary prevention, so prevention of kidney disease and treatment of kidney disease, or slowing down of kidney disease once the kidney disease is already present.
So what do we see here? That we have scientific evidence. Here’s another one. The idea that animal protein has high biological value is no longer relevant in the context of a mixed diet. So plants are the only dietary source of fiber, which shifts the gut microbiota, so the gut flora, towards increased production of anti-inflammatory substances, those substances preventing inflammation of blood vessels, and less uremic toxins and poisons. So plant fats, particularly olive oil, are anti-inflammatory and antiatherogenic, that means that they protect health of the blood vessel walls. Plant-based diets have a low net endogenous acid load. I remember 20 years ago when there were studies, they saw that in people who eat more animal protein, they have more acid in their blood, and acid damages kidneys and the circulation. And of course, plant phosphorus, like we already said in the phosphorus video, will be bound to phytate and is less bioavailable, is less absorbed, so that you have a more favorable protein-to-phosphorus ratio, even in dialysis patients.
What is more, restriction of plant foods is a strategy to prevent hyperkalemia, high potassium, deprives the patients of the beneficial effects of these plant-based foods. So what you need to see is what kind of potassium content a certain diet mix will cause, and what potassium load it will cause. Talk to your dietitian and try to balance things out so that you don’t eat a whole melon, but just only that much that doesn’t contain too much potassium, or grapes or plums or even tomato. Just a small amount and a good mix. And if there is a really problem, you can get a little bit of a diuretic which helps you remove excess potassium.
So let us translate this in practical terms. The idea that vegetable protein is incomplete is no longer sustainable. The fibers in plants have an anti-inflammatory effect because they have a beneficial effect on the gut flora. Natural vegetable fats have anti-inflammatory and vascular wall, blood vessel wall, protection effects. Plant foods produce much less acid and may slow down the progression of kidney disease. In plants, phosphorus is bound so that less of them get absorbed through the gut. Hyperkalemia can be prevented and treated with proper dietary adjustment and should not be an argument against a plant-based diet.
What does this mean in practice? Now, so here, scientific research is a very good thing and it should be a rough guide for us, but every single person will have different needs. So you have to kind of experiment and then see what is good for a given person. Not too much potassium, not too much phosphorus, but enough protein to sustain that organism at a good, well-nourished state. So we need to think through and interpret the scientific evidence and then tailor the adequate nutrition for a given person.
So eating an unnaturally high amount of protein is never a good idea. There is such a thing as golden mean, and depending on the actual needs of the person, you know, how much that person exercises, how much that person has already lost, I don’t know, too much muscle, there is an ideal, an optimum of protein that you want to eat, and there has to be a certain balance between animal-based protein and plant-based protein.
In general, it’s a very good idea, like we mentioned in the previous presentation, that we need to eat fresh, varied home meals, preferably made from local ingredients, because then all the preservatives and coloring agents and all the other agents are not in your food.
So now here comes a very important point. The worse the kidney, the less the protein it can handle, especially animal protein. But the protein intake is key to maintaining quality of life, maintaining muscle mass, and maintaining the immune system. So then if you don’t eat enough meat, that means that you will break down muscle, you won’t be able to exercise, then of course you’re going to get depressed, and on the top of all of that, your immune system will not be able to prevent infections from happening. And whenever there is infection, there is inflammation. Whenever there’s inflammation, there’s going to be heart problems and circulation problems. So then, if you are at a stage where the protein that your kidney can handle is too little, then you must start on dialysis. Why is that? Because if you don’t, then you’re going to get weak, and then you will have a high risk for infections and heart disease.
So then, luckily, we have all kinds of good things that we can eat. So we have lentil, bean, peas, and all kinds of other things. So I’m not saying that you should be a vegetarian. No. What I’m saying is that you need to restore, and if the kidney function is very low, then reverse the balance of animal-based versus plant-based protein intake. So daily protein intake should be this, and you should really starve, and the most important thing is what, what your GFR is, right? Yeah, well, if your doctor looks like this, then that’s what you’re going to hear, and then you are going to starve, you’re going to feel bad, you’re going to be depressed and get all kinds of infections, and then later on, infection, heart attack.
So numbers will not tell you what to do. What you should do is that your daily protein intake should be moderate, never excessive, and preferably predominantly plant-based, the more you are along on the trajectory of kidney disease. And if you cannot handle protein, then you should start on dialysis. So we need to prevent infections, because heart disease has a close connection with infections. So that if you start on dialysis too late and you’re going to have infections and heart attacks.
So here is a quite extraordinary article that we published in 2020, when I was a little bit younger. And in this, we emphasize that the labs are important, but yet what is most important in patients who have kidney disease is assessment of nutrition, in other words, your nutrition status. And with your nutrition status, you know, your strength, the muscle mass, and your daily activities. So these are the things that predict what’s going to happen to you: infections, heart disease, etc. So that therefore, something that is entirely subjective, that is not lab-based, not blood draw-based, it’s very important. It’s the most important thing. We need to see how well you are nourished. And so, keeping that in mind, we see that general subjective assessment of nutritional status is the single most important thing in kidney disease, not some lab value. And so one of the most important goals of treating kidney disease is to prevent weight loss, muscle breakdown, and weakness, which leads to bad outcomes.
So who lives longer with severe kidney disease? Somebody who has what? Reserves. And so when these wonderful statistical doctors, who are extremely good in science and probably everything else also, but especially good in science, they noticed that unlike in the general population, in kidney patients, it is the ones with nutritional reserves that live longer. They were surprised. I was not surprised. Why is that? Because if you have advanced kidney disease, you will not be able to handle protein intake, and you will not be able to handle good nutrition unless you are very well dialyzed. And so if it so happens that somebody is not yet dialyzed or not very well dialyzed, then it’s very important for that person to have nutritional reserves, because it’s bad nutrition that causes all the problems that happen in dialysis, including infections and heart disease, which is closely connected to infections.
So with that, I thank you for your attention and goodbye for now.
