- Every week, it seems that there's a new headline about what to eat for heart health. One day, saturated fat's the enemy. The next, it's sugar. It's enough to drive anybody crazy. Today, we cut through all that confusion. Join us as we explore a recent article that tackles this controversial topic head on. Moving beyond the simple saturated fat is bad narrative. So join me as I provide you with a more nuanced understanding of what the latest research actually says. And welcome back team to the Building a Life on Athletes podcast. Thanks so much for stopping by, really appreciate it. For those who don't know me yet, my name is Jordan Wrennke. I'm a dual board certified physician in family and sports medicine. And the goal of this podcast is to keep you actually healthy for life through actionable M&S form education. And today we're looking at a study that's diving into the topic of saturated fat and heart disease, so let's get going. So first things first of all, let's talk a little bit about saturated fat. So this is a article that comes from 2024, a systematic review and meta-analysis examining the impact of elevated saturated fat intake from full fat dairy products and red meats on cardiovascular health. Let's take a step back here. We're looking at full fat dairy products, so looking like cheese, butter, yogurt, all that stuff, and red meats on cardiovascular health. So specifically looking at kind of whole foods that we're looking at. And we care because cardiovascular disease is very important. You've probably heard me talk about this ad nauseum. It accounts for 20 to 30% of deaths worldwide, and it's thought that saturated fat intake can play a role. And this review aims to provide clarity on whether saturated fatty acids from minimally processed whole foods like full fat dairy and red meat negatively impact cardiovascular health by looking at biomarkers like LDL, HDL, triglycerides, and total cholesterol, otherwise known as our lipid panel. And the important nuance here is we're looking at whole foods, right? 'Cause all these foods aren't just bad, right? A lot of times we've heard like, what's this good food? What's this bad food? Like foods aren't necessarily good or bad. It depends on the person and all that's going on, but there are lots of things. Like you can get lots of vitamins from these things. You can get the, a lot of times the fat soluble vitamins like A, D, E, K, B. You can get minerals, calcium, magnesium, phosphorus, all that stuff. So there's definitely benefits to there, but this review aims to provide a more nuanced picture than the general dietary guidelines, right? They say keep saturated fat under 10%. That may or may not be true depending on your circumstance, but we're once again just trying to offer a little nuance. That's what we do here. So first of all, what was the setup here in the methods? Well, this was a review and it followed a PRISMA guidelines for systematic reviews and meta-analysis, meaning that we're knowing that we're going through a systematic and thorough process and it was preregistered so they couldn't change them, which is great. They looked at some big databases, PubMed, clinical, HLPE and Cochrane Library, lots of different ones, used the right terms to really make sure they're getting every article. So that's what they're looking at. They did a filter and they looked at from 2014 on, so relatively new. And they did have certain inclusion inclusion criteria like all do. So inclusion criteria specifically focused on generally healthy adults. So these people were 18 and older who are generally healthy with no preexisting cardiovascular disease, diabetes, high cholesterol or recent heart attacks, not on any cholesterol or medications as well. And so that's the big thing. These are healthy population, which is great. And the diets had to include at least 10% of calories from saturated fats, fatty acids, and minimally processed whole foods, like once again, full fat, dairy and red meat. And the outcomes they're looking for were those blood lipid values. So the cholesterol, LDL, HDL, triglycerides, things like that. Exclusion criteria was pretty much anything that wasn't those, right? So younger than 18, those on a bunch of different conditions have a bunch of different medications, all that stuff. Those are kind of the big ones there. And overall, they had about 2,500 participants in this review, so a decent sample size. And what did they find? Well, first of all, we're gonna talk about red meat and lipids, so we're gonna break this up. There were five studies with over 2,500 participants specifically looked at minimally processed red meats and regular fat and lean cuts of pork and beef were kind of by the US definition. So that's what we're looking at here. And what did they find for LDL? Well, spoiler alert, it was kind of mixed results. Like most things in nutrition, it's never that easy, right? One study found higher LDL-C with both red and white meat compared to non-meat protein, even when accounting for saturated fat. Overall, a higher saturated fat intake, mainly from high fat, dairy, and butter led to big increases in LDL, potentially in one article. Another study found no significant differences between lean red meat and white meat. And three studies found that red meat, including pork and lean beef, as part of a Mediterranean Nordic diet actually lowered LDL-C. And with the amount of red meat in a Mediterranean diet, anywhere from like 0.5 to 5.5 ounces daily did not show a dose response relationship for LDL reduction. So what do we make of that? So we'll talk more about that later, but what we got here was we found a whole bunch of things. Some studies, it increased the LDL. Some, it decreased. We found that in a healthy dietary pattern, it may have been fine. And so lots and lots of, hmm, I don't know, kind of head scratching, but interesting. And that's the world of research. That's what it is. But what did they find for HDL? Well, once again, findings were varied here. One study found a small increase with both red and white meat only in a high saturated fat diet. So if it was a high saturated fat diet, that's the only time I saw it. If it was a high lean meat, but not saturated fat, then it wouldn't necessarily see it. Another study found no difference at all. In some studies, Mediterranean diets increase HDL, and when compared to total cholesterol, the ratio got better. And differing amounts of red meats in a Mediterranean diet showed complex effects on total particle size of HDL. So moving on to total cholesterol, four studies reported significant results. More saturated fat typically tended to increase cholesterol. No difference really between red and white meat was found in one study. And then Mediterranean and Nordic diets with red meat showed a decrease in total cholesterol, actually. So once again, kind of showing that really good dietary patterns like the Nordic diet and the Mediterranean diet actually seem to have improved blood lipids. So kind of interesting. What about triglycerides? Well, triglycerides, most red meat studies found no significant changes here. One study did find a significant reduction in triglycerides with pork-based Nordic diet, but not with beef. And yeah, all of these meat studies that looked at had a positive quality rate. I mean, they're pretty good studies. So lean meat, I don't know. I don't know, it's just a shoulder shrug emoji, essentially what it comes down to. But that's what it is, and I still want to present it 'cause it's a lot more nuanced than people will want you to believe. So moving on, we just talked about that. Next, we're gonna talk about dairy and blood lipids. So there were 23 reports from 21 separate randomized controlled trials that were included with 14 using butter as the intervention or comparison. There was limited research on regular milk and yogurt, and it's kind of what I found, which is really unfortunate. A lot of the sun butter, it's 'cause butter's a hot topic. Everyone's talking about butter, right? Putting butter in my coffee, all that stuff. So it's gotten a lot of press recently, so we're talking about that. And what do we find for LDL? Well, mixed results again, but we did see some trends here. There were 11 studies showing significant changes and eight showing none. So overall, we had some. However, in these studies, butter was consistently linked to highest LDL levels compared to cheese, carbohydrates, monounsaturated fats, polyunsaturated fats, margarine, palmstarin, and olive oil. Cheese sometimes led to lower LDL than butter, but higher than other healthier fats. So essentially it was like, butter, yeah, that'll get you way up there. Cheese, sometimes not as bad, but then all the other ones are kind of down there. That's what they routinely found on a couple of them there. And they also found other than looking at like butter, they found LDL go big up, went really high up. Other things like high dairy increased, high dairy intakes increased LDL sometimes, but not always. Butter routinely did seem to do it. And yeah, that's kind of where it went to. So dairy, some, it was just very confusing. Once again, like the main topic of this is like, hey, who knows what's gonna happen? Looking at HDL, only six studies had significant findings. Higher butter intake was linked with lower HDL though. Butter showed a higher total cholesterol to HDL ratio compared to olive oil, coconut oil like that. Cheese and butter increased HDL more than a carbidge diet. Nordic diets, we've talked about in previous podcasts. Nordic diets showed a lower HDL, but increased HDL particle size. And then another study looked at sour cream caused the biggest post-meal increase in HDL, which I don't know what a post-meal increase in HDL is really gonna matter long-term. Who knows? I don't know how to classify that, but that's what they saw. And in terms of total cholesterol, six studies had significant findings, both full fat and low fat dairy in a DASH diet decreased total cholesterol compared to control. Butter led to a higher total cholesterol than a usual diet, olive oil or margarine. High dairy intake increased total cholesterol. Olive oil lowered total cholesterol compared to butter. And melted cheese actually had a different effect than unmelted cheese, which that's a whole other can of worms to look into, but I thought it was worth mentioning that even the way you cook and prepare foods might make an impact. And then finally, looking at triglycerides, eight studies showed significant effects. Cheese increased triglycerides more than polyunsaturated fats and butter in one study, so who knows what I'm making of that while butter decreased triglycerides more than high carb diet in the same study. So don't know what to make of that. Full fat dairy DASH diets lowered triglycerides compared to low fat dairy. Cream cheese caused a bigger immediate post-meal spike than butter and cheddar in triglycerides. Sour cream caused the biggest later post-meal triglyceride response, so went pretty high again. And butter intake was linked to higher triglycerides. And that's kind of what, so kind of a mixed picture here. Once again, I know I kind of sound like a broken record, like Jordan, what's going on? But I'm just reporting the results, what they find. So moving on to the next one, what do we actually make of this? So the authors highlighted that there is kind of, in three red meat studies, they found decreases in LDL, total cholesterol, and triglycerides when red meat was part of an overall healthy dietary pattern, like a Mediterranean diet or Nordic diet, even when at higher than recommended amounts of red meat. And so that's the big takeaway here is they're saying, hey, in these studies, when we saw these reductions in LDL and total cholesterol, it seemed to be part of a healthy dietary pattern. That's a big thing. And we're looking at Mediterranean as well, adding lean meats to Mediterranean diets did not seem to negate its normal lipid lowering effects. So we know the Mediterranean diet, that's been studied time and time and time again, probably the most well-researched diet out there that has lipid lowering effects, when they added lean meats to it, didn't seem to negate that. So there's some merit to say, hey, it actually may be your dietary pattern and not just this one single macronutrient that you're eating. But obviously more research is needed. The Nordic diet, which we've talked about in previous ones, very lot of similarities to the Mediterranean diet. The Nordic diet study showed LDL C reductions with both pork and beef and pork decreasing triglycerides as well, suggesting potential benefits in a diet that's similar, yeah, to Mediterranean diets. There's lots of good things there. So more individual research is gonna be there. And there are studies comparing red and white meat, suggesting no major differences in lipid effects, unless the overall diet was high in saturated fat. And that's kind of another big takeaway, right? So if you're getting lean meats, lean red meats, and they aren't high, really, really high in saturated fats, then it may not matter that much. That's the big thing. It may not have a big, big difference in your cholesterol, unless you have a high saturated fat intake, which yeah. So it may not be the quote unquote redness of the meat that's problematic, but potentially the saturated fat content. And that's, I think a pretty common thing we've seen across the line is when you have high saturated fat intake, that's when we start to see changes in cholesterol. So I think that's kind of interesting, but yeah, there's overall lean meats, lean red meats, and poultry. You might have similar heart effects in a overall health prone diet is what they recommended, what they said in this diet. I will see, but the decreases also in HTLC with red meat on a NORC diet might relate to the fact that there's a sweet spot of HDL that people have been talking about, a U-shaped relationship, meaning if your HDL is super low or super high, that might be problematic. Some people like to boast about super high HDLs. Long story short, we just don't know enough about HDL this time, but we did see that. And unfortunately for dairy, most of the research was focused on butter with limited data on milk and yogurt. And yeah, so we don't really know what to say, but the one thing is butter did consistently increase LDL compared to healthier fats and even some other dairy products. So that does kind of support the recommendations to limit its intake or replace it with other fats, potentially, if you're worried about your LDL going up. That's kind of like the big thing that consistently showed there. Dairy, we didn't necessarily see other findings like that. Cheese showed mixed effects on that with some showing increase, some not necessarily. Yogurt, once again, regular milk didn't have a lot of ones on there. And yeah, so the million dollar takeaway here, the 20,000 foot view is that everything's variable and it's gonna come down to individualized and personalized kind of stuff. So that's kind of the big takeaway is that butter does seem to increase your LDL pretty consistently. That seems like the big one. Everything else is kind of like, I don't know, we'll kind of see what's going on. But I do wanna talk about strengths and limitations of this though. Every study has strengths and limitations. This is obviously no exception. So the strengths of this review was, did use standardized outcomes. So looking at cholesterol, all that stuff. So we're looking at actual like markers, which we care about, right? No, I would have loved to see more of like mortality outcomes and that'd be great. But either way, it's consistent baseline for comparison. That's good. It did employ a systematic review and design, which was good. And all studies were RCTs, which is kind of our highest quality of evidence, which is great. And yeah, these samples used in the study found real life scenarios. And this is what I really liked about the study is there are people who did not have cardiovascular disease. There's a lot of people on the internet who will say, "Hey, saturated fat, not a problem at all. It doesn't matter at all if you're metabolically healthy." Now to make the study even better, but awesome if they would have followed and seen where their outcomes, any adverse outcomes, that'd be amazing, but that's okay. That's not what happened. But this is healthy people. This is the people on the internet. This is the people who are watching this video or listening to this podcast. The people who care, who don't, hopefully don't have heart disease yet. If you do, no worries. I'm so glad you're here. But a lot of these worry well, people like who get so worked up on stuff, they say, "Oh, this data doesn't apply to me 'cause it's unhealthy." Well, these are unhealthy populations. So that was really cool. But there were limitations. In several studies, intervention foods were often consumed in combination with the participants normal diets, making it difficult to kind of figure out, okay, what impacted it? Was it their diet? Was the study? Who knows what's going on? All studies included in the review were conducted in a relatively brief timeframe in this scope of usually weeks to months, which may not accurately affect the long-term health implications. There were definitely differences in serving sizes as well for interventions potentially impacting the dose of fat content and yeah, postprandial cholesterol response, so how you respond to after meal may be different. And the review also acknowledged the complexity of whole food matrices and understanding that when you eat a food, you don't just eat a food in isolation, you eat them together. So there's lots of overlap. There's synergistic effects of certain vitamins and macronutrients and all this stuff on other foods you eat. And so it's very, very challenging to make, you know, to isolate out, hey, it's just this red meat, it's just a saturated fat 'cause there's lots of other things that you get when you eat whole foods. You don't just eat one single thing. So what are we gonna do with this? How do we actually apply this? So I think overall, the research suggests that minimally processed lean red meats and full fat dairy products have not been demonstrated to cause negative impacts on blood cholesterol for some people, one compared to others in the study and when eaten with an overall healthy dietary pattern. So I'll say that again. I don't think lean red meats and full fat dairy are necessarily that bad when eating in the overall healthy dietary pattern. And you might be like, what's a healthy dietary pattern? Things I've talked about it all the time. Essentially making sure we have as minimally processed foods as much as possible. Lots of diversity with plant foods in terms of vegetables and fruits. You can add in if you want, whole grains and legumes, things like that. But those are generally healthy dietary patterns. And it seems like when you add in some of these things, lean red meats and full fat to that, it doesn't necessarily mean your blood levels are gonna go bad. And I say this all the time though, the dietary pattern matters most. That's why I don't say like you're on a diet or a specific this, it's a dietary pattern. It's how you consistently eat over and over and over again. It's not one single thing. I will say though, though, the one exception here in the study, the effect of butter on the LC and total cholesterol seems to be pretty consistent and agrees with the current recommendations for moderation 'cause it's pretty much gonna increase your LDL. And another big takeaway is that, yeah, I just really want you to know that your results may vary. So this is a study, we looked at thousands of people. Guess what? You're not thousands of people, you're one person. And we're not gonna know how any sort of food affects your blood cholesterol unless we check it. And you may be someone who you've eaten a decent amount of butter and your cholesterol is stone cold normal and great and fine. And like, okay, cool. You won the genetic lottery, man, that's awesome. Go for it, I'm not gonna stop you. But if you say, hey, I wanna go on this new diet, you start eating more saturated fat and your cholesterol goes through the roof, then we have to that question like, hey, how comfortable are you with this? And we kind of, that's a whole nother discussion we've had on other podcasts, but yeah, I think that's what it is. And so I think overall, you can probably eat these in moderation and not be too worried about it as long as the rest of your diet is also locked in. But that being said, I'm not gonna say, oh, like Jordan said, I can just eat as much as I want in a red meat and then all of a sudden you're taking in 700 grams of saturated fat a day. That's probably not a wise thing to do. And that's, yeah, that's general recommendations. But I always say a personalized diet is the best, right? If you wanna eat saturated fat, but are super sensitive to it, kind of like me, then I'm sorry, that may not be ideal for you. Anytime I increase my saturated fat, I start to notice my cholesterol may be, they go up. And that's like, that's what happens. And it's unfortunate 'cause I really like eating steaks and butter's delicious and all this fun stuff. But I just noticed that that's tends to happen for me. And you might decide that's fine for you. You say, hey, I'm cool with it, that's fine. I just want you to know, and I don't want you to, yeah, you need to know and you're not gonna know unless you check. But also I don't want you to blame me and say like, oh, I should be fine with this. I think everyone's gonna be in moderation. But in general, eating some of these lean red meats and full fat dairy, like you can be okay in a otherwise healthy dietary pattern. I don't think that. And ultimately, yeah, I don't want you to just ignore metric, meaning like, hey, I looked at my APOB, it's fine. Like it went up and I don't care, I feel good otherwise. Like, hey, that's your prerogative, that's totally fine for me. I'm not quite comfortable with that. But overall, there's lots of ways. But if you do eat these foods, just check, check in control, right? So we're gonna do that and see what's going on. And I'm never gonna tell you what you can and can't eat. If someone comes up to me and says like, hey, I only am gonna eat keto 'cause that's how I feel the best and everything else doesn't work for me and I can't control my weight, cool. And they say, I don't care about my LDL and saturated fat intake, it doesn't matter to me. Cool, I'm not anti that at all. I just, I'm personally, I try to control all the risk factors, right? So if you're eating all this stuff, I'll make sure your lipids are good, your blood sugars are fine, your blood pressure's fine, you're not smoking, you can't cause endothelial damage. All those things, do what you want. Like I think that you do you, boo. You can, I'm not here today. I'm just one beggar to another beggar telling me where to find food, saying, hey, this is my general approach that we can eat a health promoting dietary pattern, I think, and still have all of our risk factors in check. I think, but for some people that's not possible. Some people say, I can't do that. If you open up Pandora's box of carbohydrates, I can't do it, I'm just gonna go bananas. Cool, man, that's fine. But just letting you know that there may be risks to that that we don't quite understand yet having LDL weight through the roof, but either way, I'm totally supportive of what people want as long as we understand risks and benefits. And yeah, kind of my approach to that. But that's the cool article we talked about. I hope you found that helpful, but thanks so much for stopping by. I really do appreciate it. If you liked it, it would mean the world to me if you either liked this video or subscribed to another of your podcasts, Player of Choice, or if you shared with a friend, that'd be really the highest compliment. But that's gonna be it for today. Now get off your phone and get outside, have a great day, and 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 listing 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.
