If you go on social media, you'll see a lot of talk about protein. Some people say protein is the most important thing for a long and healthy life. Other people say that protein actually decreases your life and causes you to die earlier. Well, what's the truth? Well, today I'm breaking down an interesting article I ran across talking about the old way of thinking about protein might need to get updated. So let's get started. Welcome back, team to the Building Lifelong Athletes podcast. Thanks so much for stopping by. I really appreciate it. If we haven't had the chance to meet yet, my name is Jordan Rankey and I'm a dual board certified physician in family and sports medicine. And the goal of this podcast is to keep you active and healthy for life through actionable evidence inform education. Today we're talking a huge topic. Protein. Specifically, we're diving into the widespread fears about high-protein diets and seeing what the science actually says. So, let's get started. So, this is one article that I looked at specifically. I will link it in the show notes here, but we're talking about protein. It's kind of a unique perspective on protein. To see how much we actually need. And the old saying of too much protein might kill you, is that actually something that we need to follow? So protein is coming from just a basic nutrient, right? So, like, It's like, oh, like protein. Now it's like the central pillar of modern health and fitness culture, right? So everything is all about protein, protein, protein. Its popularity is fueled by a constant stream of new products. Protein powders, diet trends, and social media discussions, right? And its popularity has surged and so has a swirling vortex of misinformation and widespread, often sensationalized claims about the potential harms and benefits of protein. The common story online suggests that high protein intake poses a serious threat from kidney damage to bone loss, even shortened lifespan. And this article that I mentioned kind of looks into that and says: hey, what does the data actually show? And so, that's what we're going to talk about today. So. The paper we're diving into is by French et al. like I mentioned. It isn't a typical study like a randomized control trial. It's more like a perspective article, right? Which is kind of a specific format. Where experts give their viewpoint on a really important or controversial topic. So, this allows the authors to use their deep understanding of the science to take a strong position and to kind of challenge popular narratives that they feel might not be backed by the best evidence possible. And the fact that this paper even had to be written shows that there's definitely a fear of protein out there, right? So there's definitely sentiment that this can be happening. And yeah, so it's deeply ingrained in our culture that too much protein might be bad, and even inside the academic communities. And the authors literally titled it The Harms of High Protein Intake: Conjectured, Postulated, Claimed, and Presumed, but Shown. It's a pretty provocative title to kind of hopefully confront these old ideas. And the paper's core argument is super direct. In healthy people, they think there's no compelling evidence of an upper limit where protein causes disease. The authors are very clear. Just because an argument for harm sounds plausible, that doesn't mean that it's actually proven true, right? This is a big deal, right? It completely shifts the burden of proof, saying, hey. You need to actually come up with some proof to say that protein does cause these things, as opposed to just basing like basing this all on theorized things, right? So instead of the public meeting to prove protein is safe, they argue that those who claim it's harmful should be the ones providing strong, conclusive evidence. So, kind of. Turning on the head, like nu-uh, you is pretty much the scientific response happening here. But let's tackle the big first, right? So, will too much protein ruin my kidneys? That's the big question. That's what everyone talks about. This is probably the most persistent fear that we hear and see, and it's often rooted in some truth. Absolutely. So, this Brenner hypothesis suggests that the more protein you eat leads to more urea production, which is essentially a byproduct of. Breakdown and nitrogen breakdown of protein, ultimately straining renal function. And also, the paper does acknowledge, though, that there is something that happens when you have a high-protein diet. It increases the kidney's filtration rate or EGFR and even the kidney volume itself. This is known as hyperfiltration. So it filters more things going through. We know that happens. And what people say is, well, that happens, and some increased urea products. Therefore, the kidneys aren't working too hard. They're going to tap out later in life, and it's going to lead to kidney issues. That's the big thing. But here's kind of the caveat and the point they talked about. They're saying this is really important. The evidence does show that high protein intake can worsen function in people with pre-existing or undiagnosed chronic kidney disease. So they are admitting, saying, hey, If you have underlying issues, we're not talking about you. We're talking about otherwise healthy people. And so, to be crystal clear, our conversation today is about healthy individuals. But if you do have kidney disease or you know someone who does, that might be a different situation. So we're talking about the average person, no kidney disease. What's going on? And so, just talking about that before, the hyperfiltration I mentioned, well, the crucial distinction here is physiologic adaptation versus pathologic damage, right? So, the authors argue that this hyperfiltration is a normal, reversible response to a greater Load of protein, right? Not a sign of actual kidney damage. It's a great analogy of how muscles adapt and grow stronger over time, right? So under the stress of weightlifting, it's a functional increase to workload, not an injury. Like we know, that's what they're saying. This is what this is in their personal view. And they say this view is supported by strong counter-evidence, right? So, meta-analyses, Mendelian randomizations, they all found no evidence of a causal link between protein intake. And the development of kidney dysfunction in healthy subjects. One study actually of resistance-trained men consumed a very high-protein diet, up to 3. 32 grams per kilogram per day. For six months and show no adverse effects on markers or kidney health. And you might be saying, Well, six months, that's not enough. And I would agree, like, six months is not a long time. That's not 10 years of a high-protein diet. But they're saying there is data showing that, hey, it doesn't show to acutely damage things, and that's pretty high up there. 3. 32 is up there. There was another study done by the International Society of Sports and Nutrition. They state that protein intakes in the range of 1. 4 to 2. 0 grams are not detrimental to kidney function in healthy, active individuals. So, 1. 4 to 2 is kind of where the biggest recommendations are going to be for most people for like bodybuilding and lifting and muscle mass type things. And so they're saying, hey, They don't really seem to see a signal there of what's going on, of damage actually happening, but that was interesting. And so, the next thing I want to talk about is the idea that high protein consumption leads to bone loss. This concern stems from a plausible mechanism, right? The breakdown of certain amino acids creates a mild acid load, which can increase calcium excretion into the urine, known as hypercalciuria. However, This paper review, they kind of evidence show that this doesn't translate to a negative impact on bone mineral density or an increased risk of fractures. And they say, on the contrary, the majority of studies show an inverse relationship where higher protein intake is associated with a reduced Incidence of fracture. So they're saying, hey, yeah, mechanistically, there's some stuff going on that may lead to, you know, oh, you have increased calcium in your urine because it came from the bones because of the acid load, and therefore you might lead to bad outcomes, but like they don't see those bad outcomes. So that's what they're saying. A major review found that in older people with osteoporosis, it linked protein intake above the RDA. It was actually linked with higher bone density, slower bone loss, and reduced risk of hip fracture. And the key takeaway here from this section of the article was that. The potential negative effects of increased calcium excretion don't seem to be significant when dietary calcium is adequate. So, for the elderly, insufficient protein may actually be a more severe problem than excess protein intake. And a lot of times, They're saying, well, why could this be? It's plausible that higher protein intake is advantageous because it supports muscle growth, right? And stronger muscles exert greater force on the bones. And this mechanical loading actually may be a key signal for bones to increase their density and strength, which could be a huge win for them long term. And that's maybe why we're seeing that. But interestingly enough, kind of a unique perspective where mechanistically, oh, something might be going on, but the outcomes don't just seem to be there. And now let's talk about Is protein, a high-protein diet, an issue with diabetes? So, which is a big topic, right? Everyone's got diabetes, everyone's talking about it. You'll hear the claim that excess protein intake increases diabetes risks. Maybe by affecting insulin signaling. But the paper points out that this relationship is super complex and depends on the context. Like most things in science, that's what happens. There are lab studies, lots of lab studies, showing a link using isolated amino acids, which don't reflect necessarily a real mixed meal, but they do show that observational studies. Associate animal protein with higher diabetes risk, and it could be misleading potentially to a couple of confounding factors, they say. But there are definitely data out there. That's why this is like legit a confusing thing. But for example, maybe high intake of processed meat might just be a marker for overall poor diet and other unhealthy lifestyles leading to diabetes, not necessarily just a cause from eating more meat. That's just something to think about. And then. When we look at randomized controlled trials on red meat, they don't seem to show significant effects on insulin sensitivity or other glucose markers. And it does kind of question: is Protein the actual issue, or is that whole dietary package and the dietary consumption pattern you have? Is that the problem itself? But there are studies: Showing, and I say implicating the more protein you eat, that potentially the increased risk of insulin resistance. And they're saying that, hey, when you isolate it out and get rid of just a A looking at one specific nutrient and looking at a whole dietary pattern that seems to disappear is what their argument they're making. And now let's talk about lifespan, right? Everyone's talking about lifespan, longevity, longevity. That's the biggest thing on the internet right now. Yeah, and there's a big fear that a lot of people talk about that protein may be shortening your life, right? A lot of this comes from animal studies where restricting protein or calories increases longevity. But the paper cautions against applying these animal findings directly to humans. Like, it's a pretty good recommendation that you should always be careful when looking at animal studies and extrapolating them to humans. There are huge differences between a controlled lab rat study and how humans actually live, right? So, for instance, animal studies can be complicated by protein leverage, where animals on low protein diets just eat more food overall to compensate. Messing with the calorie variables. In humans, some observational studies do show a link between higher animal protein and increased mortality, but these are limited by potential lots of confounding factors, right? So. Could it just be a marker for another unhealthy lifestyle or different lifestyle choices? Who knows? Very, very hard to know. And so the paper's conclusion is: while you can't 100% rule out this harm, saying it is possible that if you eat more animal protein, you may have decreased lifespan. They're saying the current evidence suggests the link is implausible, but they're not saying entirely impossible, which I respect that humility saying, hey, that could be happening. I'm not sure, but we don't think the evidence totality sits there. And then, next, there's a thing that people talk about: this rabbit starvation myth. So, you may have heard about this historical story. Maybe not, probably not, let's be honest. I just heard about it in researching this. But, or protein poisoning is another thing people talk about. It's used as a warning for why you shouldn't eat high-protein diets. And essentially, this was a condition seen in Arctic explorers who had to survive on a diet almost exclusively of lean meat and rabbits, specifically. But the key clarification in this article is that this was not caused by protein being toxic, right? It was from a severe form of malnutrition from near total lack of fat or carbohydrates, meaning they just had protein. Very, very lean protein, no fats, and we know that you need to have some sort of fats in your diet. Um, on top of that, they're eating wild game. Like, could they have gotten sick from it? That's also a possibility, but That's neither here nor there. The body does have a limited capacity to use protein for energy, right? Without fats and carbs, the liver gets overwhelmed, potentially leading to symptoms like nausea, fatigue, and can lead to lots of issues with absorption and digestion, all that stuff. And it's a cool anecdote to like talk about saying, oh, like too much protein is there. I don't think anybody's recommending just eat straight protein. Like 100% of your macros, it's just protein. Nobody's saying that. And so that's kind of like a straw man. So, the real danger probably wasn't with too much protein necessarily, but a lack of critical or other vital energy sources and nutrients. And so, a balanced diet, most people are probably not going to run into this issue. And so We have these, right? We talked about all these harms and potentially things that we worry about, but how much protein do we actually need, right? There's a lot of confusion that comes from the misunderstanding in the RDA, which is the recommended. Daily allowance. The US RDA is 0. 8 grams per kilogram per day. That's like the minimum needed to prevent deficiency in most adults. However, it's not an optimal target for pretty much most people. It's not an optimal target for health or performance. They're saying, hey, like, this is what you need to not start breaking stuff down and do the things you need to do. But it's not like, hey, if you want to be optimal, eat here. Think of the RDA more as like the floor, right? So the RDA is the floor, not the ceiling. A more useful guideline might be the AMDR or acceptable macronutrient distribution range. This comes from the Food and Nutrition Board and the Institute of Medicine, and it's a range design to provide adequate nutrients while reducing the risk of chronic diseases. So they're saying, hey. Instead of just like the minimum, this is like this is probably a good range to be the best you can be, like to be the most healthy you can be and to reduce the risk of chronic disease. And the AMDR sets a much broader range of about 10 to 35% of total calories coming from protein, or about 1. 05 to 3. 67 grams per kilogram per day. Which is an enormous enormous range, right? So, like, a lot of times, weightlifting, let's say, like 1. 6 is probably a sweet spot, 3. 6 is like enormous, right? So, that's that's crazy. They're saying there's a huge range, and it's probably going to be okay in there. And there's a huge difference. It kind of highlights a fundamental concept, right? The protein you need is definitely contextually different and varied on a lot of things based on your lifestyle and your health goals and all those things. 0. 8 is kind of like the floor. Like we need to be at least there. Moving up to like, you know, 1. 4, 1. 6, probably going to be fine for most people. And then You know, higher needs might be for some people for some reason, but certainly 0. 8 is probably a little too low for most people. And since these needs are contextual, though, I do want to talk about some different starting points, right? So, for sedentary adults, we talked about it 0. 8. Is the minimum to prevent deficiency. That being said, though, it's not ideal. And you probably would benefit from having more protein because obviously what happens is like you eat more protein and you crowd out other things. So you're crowding out Potentially, lots of other fatty processed foods. And so that's kind of where we're going there. But as I mentioned, 0. 8. For athletes and active people, the recommendation is a little bit higher, around 1. 4 to 2 grams per kilogram to support muscle building, repair, and trading adaptations. For older adults, aiming higher than the RDA is probably crucial to prevent age-related muscle loss or sarcopenia. And as we age as well, We tend to be less sensitive to protein. So you have to eat more to get the normal response, right? So normally in your exercising, you eat protein, you have an anabolic response. That gets blunted as you age, and so you might need even more protein. So certainly want to be above the RDA there. For those who are seeking weight management, either maintaining or losing a target of at least 1 to 1. 2 grams per kilogram per day can promote sustiety. And kind of preserve lean muscle mass when we're losing and any calorie deficit. So, most people, though, will argue probably going even higher. So, higher protein intakes would probably be even better to try to maintain as much muscle mass as possible. But those are all things we need to think about. But for all these groups, Nothing recommends like pretty much 0. 8. So 0. 8 is like, hey, this is what you need to exist. Probably need to go above that a little bit. And now I do want to talk about protein source and diet quality. So this is kind of a critical concept, right? The potential harm. From a high-protein diet isn't often the protein, but the dietary package it comes in specifically. That's kind of think about a healthy dietary pattern. I talk about that all the time. The dietary pattern is very, very important. And when you remove that and just isolate on one macro, that's where we start to get into issues. A diet getting its protein from fatty processed meats while being low in fiber is much more likely to be a problem. Not necessarily the protein itself, right? So you're just eating processed junk all day, every day. It's not necessarily the meat that's causing the issue, it's probably everything else. There's something called the crowd out effect, right? So, focusing too much on just protein can also displace other important vital foods like vegetables and fruits and can lead to nutritional deficiencies. And I know, like, people might say in the low-cover community. Meat's got all you need, and it's fantastic. It's all you need. But you do have to be conscious if you're not eating anything else of making sure you're hitting your other nutrient needs, right? That's just like a fact. Like, if you go on a restrictive vegan diet, you have to be careful, or you got to get B12 somewhere, right? It's the same thing if you're on a very, very strict Carnivore diet, you might have to consider where to get this other nutrients, just something to think about. And overall, like the MyPlate guidelines are the recommendations, they recommend choosing a variety of different foods and protein sources as well, prioritizing leaner sources. Um, and also, you can mix in plant-based options, right? You can do tried beans, lentils, soy, tofu, all those ones. Those can be an option as well. If people are like, I don't want that much animal protein, you can do that. So, um, but yeah, you important to always read your labels. Look at all that stuff. Variety is key. Look at your labels, make sure you're not just sneaking things in. So, just things to think about when looking at protein sources. interesting thing it talked about in this paper was it kind of gave us a great lesson on how these potential logical fallacies they kind of in these myths how they survive and how they're pervasive. Right, so a big one is kind of grand for fathering knowledge, right? So, where old, unsubstantiated claims get passed down, saying, Hey, like citations keep getting repeated, saying, Hey, we think we were worried about this, and then another one claims that and cites it and cites it. And it can then seem like an established fact. So, for example, a claim that 3. 5 gram per kilogram per day is the upper limit for protein is often cited, but the paper points out that the original source for that claim doesn't actually support it. So, meaning, like, hey, They made this claim, but they didn't have any source on it. So it's kind of interesting, right? It can be amplified by a bunch of different reasons, and it can also be amplified by a confirmation, right? Right, our natural tendency To seek out and believe information that confirms our pre-existing beliefs, we all have it, all of us. So, if you're saying I don't have that, no, you definitely do. We all have preconceived notions, and I'm definitely in this side. I kind of think protein is not as bad. And so, seeing different takes as well, like hey, how protein can be harmful mechanistically is helpful to kind of temper my expectations. I recognize that. But yeah, because the idea is that like you always have some thought in there of what's going on. So we have to think about that. But this idea of like too much of a good thing sounds reasonable, right? And it's plausible, but not necessarily. Proven with robust, robust data. It's definitely mechanistically possible. So I'm not saying it can't happen, but it doesn't seem to be like one for one always happening. On understanding these mechanisms, definitely help us Become more discerning and understand, like, hey, we have to look out for this and that. And so, that can be very helpful. But it kind of a lot of times, maybe that was there mechanistically. And we just said, hey, because of that, we're worried about this without having the other steps to prove that it's actually causing these bad outcomes, if that makes sense. And so, what's the final verdict? Well, according to this paper, for healthy people, widespread fears about kidney damage, bone loss, or diabetes from high protein aren't supported by strong scientific evidence. Physiological effects like increased kidney filtration are best understood as benign functional adaptations, not pathological harm, right? So, the RDA we talked about, that's the minimum to prevent deficiency, not an optimal target for most of us. And higher intakes are not only safe but beneficial for goals like building muscle and overall bone health. So, the true danger isn't the protein itself, right? But the overall dietary context: the source of the protein and what other vital nutrients may be displaced. Play a role. And for a healthy person, protein is safe and a powerful tool, right? The focus should shift from fear of too much to a strategic understanding of how much is needed for your individual goals. All while prioritizing a balanced, high-quality diet. That's kind of my take on that. But overall, interesting article. I thought it was kind of cool as a viewpoint. I thought it was well balanced saying, hey, they did the research. And once again, they didn't talk dogmatically, saying, Oh, protein's fine. Like, don't worry about it. They're like, well, because of this, I don't think it's there. And so I'm sure you could get a other one on the other side, someone from a more plant-based side or. You know, saying, Hey, protein's actually bad, and this is why, and that's what's cool about science. You can go back and forth. And so, I thought it was a unique take. Hopefully, you'd enjoy that. But that's going to be it for today. Thanks so much for stopping by. If you did enjoy this podcast, it would mean the world to me if you either share this with a friend, left a five-step review on your podcast platform of choice, or subscribed on YouTube. But that's it. So get off your phone, get outside, have a greater day. We'll see you next time. Disclaimer, this podcast is for entertainment, education, and informational purposes only. The topics discussed should not solely be used to diagnose, treat, or prevent any condition. The information presented here was created with an evidence-based approach, but please keep in mind that science is always changing, and at the time of listening to this, there may be some new data that makes this information incomplete or inaccurate. Always seek the advice of your personal physician or qualified healthcare provider for questions regarding any medical condition.
