Bite Back with Abbey Sharp - The SURPRISING Truth About Butter, Saturated Fat & Health (The Research SHOCKED Me!) | Fat Wars Part 2

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Starting point is 00:00:26 Discover Coffee Plus on Nispresso.com. Removing butter is not the intervention. What you put on the plate in its place is. Welcome to another episode of Bite Back with Abby Sharp, where I dismantle diet culture rules, call out the charlatans spinning the pseudoscience, and help you achieve food freedom for good. At some point in the past 20 years, butter stopped being a banal ingredient in your grandmother's muffin recipe and started to take on its own cultural identity. It became a symbol of real food, a stand-in for wholesome tradition, a badge of purity, and a profound moral statement, which is kind of extraordinary when you consider where butter was sitting

Starting point is 00:01:17 culturally just a few decades ago. For most of the second half of the 20th century, butter was practically the poster child for what nutrition experts told us not to eat. It was a fat, and fat, fat, apparently made us fat, but even worse, it was a bad fat. And so in its place came margarine. Cheaper, lower and saturated fat, scientifically engineered, and aggressively marketed as the enlightened heart-conscious alternative. And the people ate it up. Like literally.

Starting point is 00:01:56 Between 1942 and 1972, butter availability in the United States dropped from more than 16 pounds per person per year to just five, while margarine overtook it in sales by the late 50s and ultimately peaked by the mid-70s. But then the story started to unravel. Because a lot of those old-school margarins were made with partially hydrogenated oils, which could contain industrial trans fats. And unlike the increasingly complicated conversation around saturated, fat, the evidence on artificial trans fat became unequivocally clear. Transfat raises bad LDL cholesterol, lowers good HDL cholesterol, and increases the risk of cardiovascular disease. Eventually, the FDA determined that partially hydrogenated oils were no longer recognized as safe and largely removed

Starting point is 00:02:55 them from the American food supply. Suddenly, the supposedly scientific replacement for butter didn't look so clever anymore. And so began Butter's Great Redemption arc. By 2005, Americans were once again consuming more butter than margarine, giving way to the Atkins resurgence, followed by paleo, keto, and eventually carnivore. And by 2014, Time magazine put a giant curl of butter on its cover with two very large words, eat butter. And culturally, the case seemed like it was close. Butter had not simply been welcomed back into the kitchen, it had been exonerated, vindicated, almost martyred as it became proof that nutrition authorities everywhere had lied to us. And this is where I think the story gets really interesting, because there was such a legitimate and much-needed course correction happening here. For years, we had dramatically oversimplified dietary fat by encouraging folks to focus on total grade.

Starting point is 00:04:02 grams of fat, far more than the important question, which was what was going to replace that fat. We sold highly refined low-fat products as inherently healthier, even when the removed fat had simply been replaced with refined starches and added sugars. And we allowed foods containing industrial trans fat to wear a heart health halo simply because they were saturated fat-free. Those were real public health mistakes that we need to call out and own. But we're now facing a very different mistake, where the very valid acknowledgement that we were wrong to demonize all dietary fat morphed into the more muddy, we were wrong about saturated

Starting point is 00:04:49 fat, which has now become eating more saturated fat is actually healthy. More specifically, that butter, tallow and coconut oil are superior to handmade vegetable or seed oils, and anybody who's telling you otherwise is repeating debunked nutritional dogma. Those are four very different claims. Correcting an overly simplistic nutrition message does not mean that every piece of science underneath that message was wrong. So while we were certainly in need of a correction, does it warrant a full-blown butter coronation? Well, today we're going to be building on what we discussed in part one of the Fat Wars series here to figure out where the pendulum should actually stop. Is saturated

Starting point is 00:05:36 fat genuinely harmful? Does butter really raise your heart disease risk? What about its impact on HDL and so-called fluffy LDL? Do coconut oil, beef tallow, cheese, and butter all behave the same way just because they're rich in saturated fat? And perhaps most importantly, if you eat less butter, what are you eating instead? Because that question turns out to change almost everything we think we know about fat. All right friends, one last thing. If you are new to bite back, welcome. I would really, really love if you would hit subscribe or follow wherever you're watching or listening right now, and if you would share this podcast with a friend who is always going on about their latest fad diet. Also, if you prefer short of form content, absolutely check me out at Abby's Kitchen on

Starting point is 00:06:29 IG and TikTok. All right, friends, get yourself a glass and wine or some coffee and your favorite snack, because we are going deep with this one. All right, friends, let's dive in. Okay, so to set the stage, we got to do like a little biology lesson and talk about cholesterol and heart health, seeing as the historical argument against saturated fats are that they increase the risk of heart attack and stroke. So very quickly, cholesterol is an essential waxy lipid molecule that is essential for cell membrane structure, bile acid production, cell signaling, hormone production, and honestly, so much more. The problem isn't that cholesterol exists in the body. The problem, when we're talking about atherosclerosis, is prolonged exposure to too many APOB-containing lipoprotein

Starting point is 00:07:20 particles that can enter and become retained in the artery wall, delivering cholesterol that ultimately contributes to plaque. So let's just unpack that very complicated sentence. LDL, commonly called bad cholesterol, isn't actually cholesterol itself. LDL is a lipoprotein particle that carries cholesterol and other lipids throughout the blood. HDL is another lipoprotein involved in transporting and exchanging cholesterol throughout the body, including pathways that ultimately return cholesterol towards the liver. The measurement LDLC tells us how much cholesterol is being carried inside those LDL particles, while APOB gives us a sense of the total number of atherogenic particles,

Starting point is 00:08:07 including LDL, remnants, and LPA. Simply put, cholesterol is the cargo, LDL is the delivery truck, LDLC tells us how much cargo is in the LDL fleet, and APOB tells you roughly how many atherogenic trucks are on the road. While there's way more nuance that we're going to dive into, the reason for the long-standing saturated fat fears is the repeated finding that a diet-rich and saturated fat raises LDL cholesterol. And just to complicate things right out the gate, saturated fat is not actually one fat. It's a family of different fatty acids, and some particularly meristic and palmitic acid are potent LDL razors,

Starting point is 00:08:54 while others like stearic acid may have a much smaller effect. We're going to come back to why that means that butter and coconut oil or beef tallow are not metabolically interchangeable, but that brings me to another nuance worth untangling, particle size. Because like saturated fats, LDL particles are also not all identical. LDL particles exist across a spectrum of sizes, although they're often broadly discussed as either small and dense or large and buoyant, or what the internet affectionately calls big and fluffy. Research suggests that it's these small dense LDL particles that are most strongly associated with insulin resistance and an increased risk of coronary heart disease. Some, but not all trials, suggest that increasing saturated fat increased the massed, of large LDL particles, leading a lot of carnivore enthusiasts to claim that even if their

Starting point is 00:09:53 animal and butterfilled diet did increase their LDL, if that LDL was suddenly all the big fluffy stuff, then it's all good, right? Maybe not. First of all, it seems that the most striking, kind of small to large particle shift seen in a lot of these keto-style dietary patterns occurs with carbohydrate restriction and reductions in triglycerides. Not necessarily because saturated fat itself has some unique LDL fluffing capability. In Toronto, every arrival is a statement, and nothing says it better than this. Cadillac Optic was the number one selling luxury EV in Canada for 2025. Find your rhythm across a seamless 33-inch display and an immersive 19-speaker AKG surround audio system.

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Starting point is 00:11:20 ahead, don't change your morning. Let your morning change you. Discover coffee plus on espresso.com. Second, particle size might not be the most important consideration. Particle size may tell us something about the metabolic context, but the total concentration of circulating APOB containing particles may be far more telling. According to a recent 2025 analysis of more than 207,000 people, they found that as soon as the total APOB particle number was accounted for, LDL particle size, subclasses stopped predicting coronary disease. So like back to our cargo truck analogy, a big truck may carry more cholesterol than a small one, but it still has an APOB license plate and can still enter the artery wall.

Starting point is 00:12:16 So if your saturated fat diet turns your LDL into bigger trucks, but also puts more trucks on the highway, don't worry they're fluffy, isn't exactly reassuring. But what about saturated fat's impact on our so-called good HDL levels? Because yes, saturated fat can raise LDLC, but it can also raise HDLC. So do these two things just cancel each other out? Again, no.

Starting point is 00:12:44 Cardiovascular biology is not a scoreboard where one point for HDL erases one point for LDL and the match ends the draw. Higher HDLC is associated with lower risk, but simply raising HDLC has not been shown to protect us from heart disease. Meanwhile, if a dietary change is increasing the number of APOB containing particles circulating in your blood, that is an atherogenic change. and a simultaneous rise in HDLC does not magically neutralize it. So we've established something that is actually pretty difficult to argue with in the research.

Starting point is 00:13:23 And that is that certain saturated fats, particularly pulmetic and meristic acid, can raise LDL and in some cases also APOB. But of course, nobody actually cares that much about lowering a number on a blood test just for the satisfaction of watching the number go down. The question we really care about is, does that increase in LDL translate into more actual heart attacks, strokes, and cardiovascular deaths? And this is where the evidence gets considerably messier. Because we can lock people into controlled feeding studies for like a few weeks, carefully manipulate the fat in their diets, and watch their LDL change. What we cannot

Starting point is 00:14:05 realistically do is randomly assign thousands of people to eat butter or olive oil for 30 years, and wait to see who has a heart attack. So to answer the heart disease question, we're kind of forced to combine several different types of evidence. Short or controlled feeding studies, longer-term observational cohorts, and the relatively small number of older randomized control trials that actually measured cardiovascular events.

Starting point is 00:14:28 And sometimes they don't tell us a perfectly neat story. If you've been on carnivore talk, you've maybe heard about two famous trials that the seed oil skeptics love to cite. the Sydney Diet Heart Study and the Minnesota Coronary Experiment. In Sydney, 458 men who had already experienced a coronary event were randomized to an intervention intended to replace saturated fat sources with polyunsaturated safflower oils.

Starting point is 00:14:58 The control group did not receive the same dietary intervention. When previously unpublished data were recovered and reanalyzed years later, the intervention group had lower cholesterol, but higher all cause cardiovascular and coronary mortality. I'm sorry, what? Then in Minnesota, more than 9,000 institutionalized participants were randomized to a diet that replaced saturated fat with corn oil and corn oil margarine. Cholesterol dropped substantially, but mortality did not.

Starting point is 00:15:34 And again, in a secondary analysis, they found that the greater reductions in cholesterol were actually paradoxically associated with higher mortality. Obviously, these unexpected findings deserve attention, but they also warrant further scrutiny. Sydney was a relatively small study in men who had already experienced coronary disease, and its intervention produced a very unusual high linoleic acid dietary pattern without a corresponding omega-3 increase. Minnesota involved institutionalized populations,

Starting point is 00:16:09 many participants were not exposed to the experimental diets for very long, and both studies were conducted in the 60s and 70s in an entirely different cardiovascular treatment era. The exact composition of historical margarins also wasn't characterized with the precision that we would expect today. That said, I would not simply waive these trials away by blaming trans fats. I mean, they are offering legitimate randomized data points that deserves to live in the evidence-based. They just probably shouldn't get to be the entire evidence-based, especially because we've accumulated way more research since then. So one 2015 meta-analysis

Starting point is 00:16:51 of observational studies found no clear association between saturated fat intake and all-cause mortality, cardiovascular disease, or coronary heart disease outcomes. An earlier 2010 cohort meta-analysis reached a similar conclusion. And a 2016 review, provocatively titled Butter Back, found that eating an additional tablespoon of butter per day was essentially neutral for cardiovascular disease, with only a very weak association with total mortality. Those papers were enormously influential in butter's rehabilitation, and understandably, but there are two big glaring issues with them. One, again, they were largely observational studies where butter consumption would travel alongside loads of other behaviors. And,

Starting point is 00:17:39 that researchers can't perfectly separate. And two, most importantly, simply asking whether people ate more or less saturated fat tells us nothing about what replaced those calories. In other words, is heart disease lower specifically because you added saturated fat or because you've reduced your sugar or refined carbs? Thankfully, we've just recently got some new hints here. In 2025, researchers followed more than 221,000 adults from three major U.S. cohorts for up to 33 years. The people with the highest butter intake had about 15% higher total mortality than those with the lowest,

Starting point is 00:18:27 while higher plant oil intake was associated with lower mortality. Statistically, replacing 10 grams of butter per day with plant oil was associated with about 7,000. 17% lower total mortality. Now remember, this is an observational study. Association, not proof of causation. And importantly, that specific butter to plant oil substitution did not produce a statistically significant reduction in cardiovascular mortality. So I wouldn't turn this into like butter kills. But it certainly complicates the idea that modern long-term research has completely exonerated butter while condemning vegetable oils. So then we move to look at the more valuable randomized control trials, which is honestly where things get even more chaotic. One 2025 systematic

Starting point is 00:19:19 review of nine randomized control trials found no statistically significant reduction in cardiovascular mortality, total mortality, myocardial infarction, or coronary events from reducing saturated fat. The authors went And so far as to conclude that saturated fat restriction could not currently be recommended for preventing cardiovascular disease and mortality. But then a larger 2025 risk stratified review looked at 17 randomized control trials and more than 66,000 adults. And it felt something a little more nuanced. For people who started at low cardiovascular risk, the absolute benefit of reducing or modifying

Starting point is 00:20:03 saturated fat over about five years was very small. For people at higher cardiovascular risk, the potential absolute benefit became more meaningful. And critically, when saturated fat was specifically replaced with polyunsaturated fat, the risk of non-fatal heart attack was about 25% lower. Hmm. Okay. Well, how the heck the two reviews published months apart, still appear to tell us very different things? Well, that's nutrition research for you, baby. Different inclusion criteria, populations, baseline risk, interventions, amounts of saturated fat actually reduced,

Starting point is 00:20:46 and most notably different replacement nutrients, which means different results. Across Canada in a Volvo. Destination, Vancouver, turn left to leave. Travel west through Approaching Continue toward You've arrived

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Starting point is 00:22:21 Which brings us to the most important question we need to ask to get to the bottom of the fat wars. If we're saying saturated fat is good or bad for heart health, what are we comparing it to? Because when you remove butter, something else is going to replace it that is going to influence the health outcome. Or maybe you remove the butter and you don't replace those calories at all, creating an energy deficit, potentially changing body weight and a bunch of other risk factors at the same time. So anytime someone quotes a study that found that reducing saturated fat doesn't prevent heart disease, What we then need to find out is what filled the butter gap. One likely reason so many observational studies that helped rehabilitate saturated fat found little or no association with heart disease is that they didn't adequately account for the replacement.

Starting point is 00:23:15 If the comparison nutrient is essentially whatever else people happen to eat, including refined starch and sugar, the benefit of eating less saturated fat can disappear. That doesn't mean that saturated fat is something. how heart protective, it might mean that the replacement sucked. The replacement is not just some minor statistical nuance. The replacement is the experiment. So when researchers actually account for what is filling that saturated fat gap, a lot of the apparently contradictory research starts to make more sense. So let's start with carbohydrates. Because according to a major meta-analysis of 60 trials, if you replace saturated fat with, With carbohydrates, LDL will generally come down somewhat.

Starting point is 00:24:04 But if those carbohydrates are predominantly refined starches and added sugars, you simultaneously lower HDL, raise triglycerides, and promote the kind of chronic disease causing lipoprotein profile that we really don't want. So you've kind of improved one number while likely worsening others. Now let's talk about unsaturated fat. That same meta-analysis found that when people replaced saturated fat with unsaturated fats, LDL came down without the same triglyceride penalty, and the total cholesterol to HDL ratio also improved. But again, blood work is not really the

Starting point is 00:24:43 endpoint we're ultimately interested in. We want to know whether people actually have fewer heart attacks. And we've got data on that too. One landmark analysis pooled data from 11 prospective cohort studies involving almost 345,000 people to see what happened. when 5% of calories from saturated fat were hypothetically exchanged for something else. When those calories were replaced with polyunsaturated fat, aka those seed oils that we love to hate, coronary events were about 13% lower and deaths from coronary heart disease were about 26% lower. But when saturated fat was replaced with carbohydrate as a broad category, there was no cardiovascular benefit. Coronary events were actually modestly higher in that particular analysis.

Starting point is 00:25:34 Now, that study didn't do a very good job distinguishing Ebola steel cut oats from a Pop-Tart. And as you can probably imagine, that distinction matters. But a massive 2015 prospective study did. They found that when 5% of calories from saturated fat were replaced with polyunsaturated fat, again, that's the seed oils, coronary heart disease risk was about 25% lower. When it was replaced with mono-unsaturated fats, those are the things that we find in olive oil or avocado oil, the risk was 15% lower. And when it was replaced with whole grains, the risk was 9% lower. But when folks replaced their butter for sugar or refined starches, they saw no significant reduction in heart disease risk. But again, all observational. So let's talk about the randomized control trials.

Starting point is 00:26:24 According to a large 2020-Cockering review, a 15 long-term randomized trials and 56,000 people, reducing saturated fat, did not clearly reduce total mortality or even cardiovascular mortality. But it did lower the risk of combined cardiovascular events by roughly 17%. Even more impressive, though, were the results of a 2025 systematic review with 17 randomized control trials. Again, the impact on mortality and cardiovascular events didn't seem like anything to write home about until they look specifically at comparison nutrients. When saturated fat was being replaced by polyunsaturated fat, non-fatal heart attacks were about 25% lower. And that benefit was much more potentially meaningful for people who already started at high cardiovascular risk.

Starting point is 00:27:20 So the evidence isn't telling us butter is poison, or even that eating less saturated fat is automatically healthier. It's telling us something much more nuanced and hierarchical. If you replace butter with refined starch and sugar, you may accomplish very little. With whole grain carbohydrates or plant proteins, now you're getting a little improvement. With mono-unsaturated fats,

Starting point is 00:27:46 particularly from plant foods like olive oil, nuts, and avocado, and you'll likely see a reduction in risk. And finally, if you replace your butter with foods rich in polyunsaturated fats like nuts, seeds, fatty fish, and unsaturated plant and seed oils, that is where we see the clearest cardiovascular win. So once again, removing butter is not the intervention. What you put on the plate in its place is. Now there's one last tiny little wrinkle here because I have been using saturated fat and butter somewhat interchangeably for this podcast, and metabolically, that isn't entirely fair. Saturated fat is a family of different fatty acids, and different foods contain different combinations and permutations of them. Butter, for example, contains a lot of pulmitic and meristic

Starting point is 00:28:38 acid. Two of the saturated fats, particularly at fault for raising elizabeth. ldl. Coconut oil is actually more saturated than butter over 90%, but roughly half of it is a medium chain triglyceride called loric acid with far less palmitic acid. And that different fingerprint seems to matter. And one randomized control trial comparing 50 grams per day of butter, coconut oil and olive oil, butter raised ldial significantly more than either coconut or olive oil. Now before the coconut oil lobby pops the champagne, when researchers have pooled clinical trials, coconut oil still raises LDL by about 10 milligrams per deciliter compared to other vegetable oils. So coconut may behave somewhat better than butter

Starting point is 00:29:24 in some direct comparisons, but still likely worse than canola, soybean, or olive oil. And then there's the uber trendy beef tallow. It's actually only about 50% saturated, with more than 40% of the same heart-healthy mono-saturated fat that is olive oil. claim to fame. And while we definitely need a lot more robust research for like officially ranking the healthfulness of each oil and fat, one tiny study found that butter produced the highest LDL followed by beef tallow and then cocoa butter and then olive oil. But just because one saturated fat may produce a more favorable lipid response than another doesn't automatically make it a superfood.

Starting point is 00:30:08 Tallow raises LDL less than butter is not the same claim as Tallow is better for cardiovascular health than unsaturated plant oils. And then there's one more tiny little twist to throw in the mix here. Even foods containing very similar saturated fatty acids don't necessarily behave identically. Take cheese, for example. If saturated fat were the only thing that mattered, you might expect dairy fat eaten as cheese to affect cholesterol exactly the same way as dairy fat eaten as butter. But it doesn't. In a randomized control trial of 92 adults, LDL was about 3.3% lower after the cheese diet compared to the butter diet. Why? Likely because of the food matrix of cheese where the calcium, protein, fermentation, physical structure,

Starting point is 00:30:56 and the way that fat is packaged within that food affects our body's response. So now we have two separate layers of nuance. Different saturated fatty acids can behave differently and the same fatty acids can behave differently depending on the food matrix, their packaged in. So this is just another reminder that nutrition labels kind of flatten a lot of biology into one number, and honestly, the devil is actually in the details. So where does this leave us? The way I see it, the problem with the low-fat era wasn't necessarily that we identified saturated fat as something worth moderating. The mistake was acting as though anything was healthier simply because it contained less of it. A fat-free cookie wasn't car.

Starting point is 00:31:43 protective because somebody removed the butter. And conversely, your salad doesn't become dangerous because you dressed it in canola oil. What we've learned over decades of research is that the health effect lives heavily in the substitution. Compared with what is the question that actually makes the seemingly contradictory saturated fat evidence makes sense. And that doesn't mean we need to swing the pendulum straight back to 1993 and start counting fat grams. So here's my evidence-based bottom line take. Use unsaturated fats including olive oil, avocado oil, and yes, those demonized seed oils as your everyday default more often than fats dominated by saturated fat. Two, let better coconut oil and tallow be foods that you use when

Starting point is 00:32:31 their flavor or culinary function actually adds something you value, not because wellness culture convinced you their medicine. And three, aim to get most of your fats from nutrition, nutrient dense whole foods like avocado nuts seeds and fatty fish because butter does not need to be poison in order for olive or canola oil to often be the better cardiovascular choice and seed oils doesn't need to be a superfood for replacing some of your butter with it to make sense butter deserved a correction but not a coronation and on that note i'm going to make myself some avocado toast for breakfast if you are not already i would really appreciate you subscribing or following to the podcast wherever you are listening or watching.

Starting point is 00:33:15 And also, please leave me a five-star review. It really does make all the difference in helping me get the word out. And as you can probably see, this is a lot of work. There were, I don't even know how many citations in this one, but, you know, your girl was deep in the stacks. But until next time, signing off with Science and Sass. I'm Abby Sharp. Thanks for listening.

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Bite Back with Abbey Sharp - The SURPRISING Truth About Butter, Saturated Fat & Health (The Research SHOCKED Me!) | Fat Wars Part 2

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