Ben Greenfield [00:00:00]: My name is Ben Greenfield, and on this episode of the Ben Greenfield Life podcast.

Dr. Cate Shanahan [00:00:04]: When you use these things to cook with in a restaurant situation in a deep fryer, scientists have tested the amount of toxin that develops so they can tell you how much you're getting when you eat fries from a place like McDonald's or Burger King. They found that the amount of these alpha beta-unsaturated aldehydes is equivalent to the amount in a cigarette. Like on a one-to-one basis, one french fry equals the toxicity of smoking an entire cigarette. So if you give these to your children, it's like giving them cigarettes. I'm not saying this till they blame parents or put shame on any parents. It's a shame on the folks who've been claiming that these oils are heart-healthy and promoting them without any regard to the reality of their chemistry and what the toxicologists have been trying to warn for decades.

Ben Greenfield [00:00:57]: Fitness, nutrition, biohacking, longevity, life optimization, spirituality, and a whole lot more. Welcome to the Ben Greenfield Life Show. Are you ready to hack your life? Let's do this.

Ben Greenfield [00:01:21]: My guest today has been on the podcast. I thought just once, but when I was preparing for the show, I realized she'd been on the podcast twice. Cate, it was years ago. We were trying to figure out, I think my sons were four or five the last time I had you on the podcast, and they're 16 now, so you do the math, like a decade ago.

Dr. Cate Shanahan [00:01:40]: More. Yeah, yeah.

Ben Greenfield [00:01:43]: We did a podcast about your book, Deep Nutrition, which is still, I mean, back then, it was the number one book that I recommended to people for nutrition. It's still an excellent title because you do such a good job delving into the deep research, I guess in this case, pun intended, on how our body metabolizes nutrients. And you as an MD and a physician-scientist who kind of has worked with a lot of athletes and also really understands the medical side of things, you do a really good job unpacking quite a bit. And so, even though there are so many people right now talking about seed oils and vegetable oils and are they good and are they bad? You know, I think that this book, I'm going to hold it up for folks. This new book that you've written, Dark Calories, my copy says, coming in June 2024, not for sale, which means that since we're recording this now in July, it's for sale now, right?

Dr. Cate Shanahan [00:02:43]: It's for sale. And it looks very similar.

Ben Greenfield [00:02:47]: Well, it is. It's just fantastic. I mean, again, if you're watching the video version, this book, you can see all the pages that I have folded over, just one of the best expose and treatises on why you should be thinking about the oils you're consuming and the real truth about seed oils. So, first of all, I'll link to the book if you're listening in or watching, and everything that Cate and I talk about, as well as the previous two podcast episodes that we did, which are also fantastic. If you go to BenGreenfieldlife.com/darkcalories, that's BenGreenfieldlife.com/darkcalories, where you can learn more about Cate and the work she's done with pro athletes and athletic teams, and the work she's done in medicine and her research and her writing. But I really just want to dive deep today into this concept of Dark Calories, how vegetable oils destroy our health, and how we can get it back. Are you ready for this, Cate?

Dr. Cate Shanahan [00:03:48]: I am so excited. Take a dive with it.

Ben Greenfield [00:03:53]: All right, let's do it. So, let's just start right here. You say in the book that even the people, which it seems like a lot of them now, including me, who are warning that seed oils are harmful, are underestimating the extent of the problem. So what do you mean when you say that?

Dr. Cate Shanahan [00:04:14]: Yeah, so, well, you're familiar with my work. At the very beginning of my dive into nutrition, I realized that vegetable oils were really bad for us. And I also was talking about sugar and its role in harming our health and disrupting normal growth and all the harm that it does. But I wasn't clear in the beginning which of the two was worse. As time has gone by and more folks have come to understand that, yes, vegetable oils do promote oxidation. I've continued my research and discoveries, and I've discovered that oxidation truly is the root cause of literally everything that ages us. Like, accelerates our aging.

Dr. Cate Shanahan [00:05:06]: It kills us, even if, under the best of circumstances, it's oxidation and oxidative stress that ultimately lead to our demise and determine our lifespan. Right, which is supposed to be around 100 years, give or take, and not what sugar does. So, the vegetable oils drive oxidation and oxidative stress, but sugar mostly is about glycation. And when you compare these two chemical processes, which I've done, glycation is not anywhere near as bad. It's like one, 1000th or a billionth in some cases, the speed of the reactions, and it's not as ubiquitous. Sugar is regulated, so you can't have it just go out of control, but oxidation can.

Ben Greenfield [00:05:57]: Now, what I know about oxidation. It's been a long time since I took chemistry, but I did take chemistry in high school and in college, is that when you donate an electron to something, that's called reduction, and when something is missing an electron or you take an electron away from something, it's called oxidation. Right. Normal chemical reaction. Why would that be a bad thing?

Dr. Cate Shanahan [00:06:23]: It's necessary for life. It's how we generate energy. But oxygen is the main molecule of oxidation in the body. That's why, in fact, we call the reaction oxidation, because it's oxygen molecules that are responsible for stealing these electrons. And oxygen is how we generate energy. But oxygen is also itself a dangerous molecule, so it's what kills us too. We have to keep it in control. We have to keep these reactions in control.

Dr. Cate Shanahan [00:07:00]: And biology has been battling oxidation reactions for billions of years. And normally, our biology can keep oxidation under control. When I say normal, I mean normally on a normal human diet, which we are no longer consuming, and on a diet that's high in vegetable oils and processed foods, we simply cannot control oxidation reactions. And this accelerates the demise of every cell and it accelerates the inflammatory process. What you get when oxidation reactions go out of control is something called oxidative stress. Oxidative stress drives the two most common disease processes in the world, and that is inflammatory diseases like asthma and allergies. And that drives autoimmune diseases too, and degenerative diseases.

Ben Greenfield [00:07:58]: Yeah, yeah. A lot of people might be scratching their heads because you said that this oxygen is related to oxidation. And then, of course, we brought up vegetable oils as one of the primary causes of oxidation. Put those pieces together for me, because it's not like somebody picks up a bottle of canola oil and says, oh, this is full of oxygen that's going to oxidate my body. So can you clarify a little bit how these pieces actually work together?

Dr. Cate Shanahan [00:08:26]: Yeah. So oxidative stress is definitely not caused by too much oxygen in the air or you don't have to worry about how fast you breathe or anything like that. Oxidative stress is in modern times. Now, our problem with oxidative stress is coming from the fact that these vegetable oils contain toxins that eventually deplete our body's ability to control oxidation reactions. They deplete our antioxidant systems. So I'm talking about the antioxidants themselves, like vitamin E and vitamin C. I'm talking about the enzymes that control oxidation. Maybe you've talked about these before, like superoxide dismutase and catalase.

Dr. Cate Shanahan [00:09:15]: And so on. And they also deplete the intermediate products. Our bodies spend a lot of energy controlling oxygen. Antioxidant enzymes are the most prevalent types of enzymes in our mitochondria. And around our mitochondria and our mitochondria, where we use oxygen, our mitochondria generate energy for us. And they do that with oxygen. So our bodies are designed to be able to handle oxygen and oxidative stress. But what vegetable oils do is deplete that antioxidant arsenal.

Dr. Cate Shanahan [00:09:55]: And they make it impossible for our cells to generate energy without experiencing undue amounts of oxidative stress. And there are other effects that they have in our bloodstream, which have nothing to do with energy generation either. But it all comes down to the fact the way that vegetable oils are processed and their fatty acid composition. Because the vegetable oils that I identified as the problematic ones, I call them the hateful eight. Like, there's eight of them. I'm just gonna like corn, canola, cottonseed, soy, sunflower, safflower, rice bran, and grape seed. Just so you know what we're talking about here. We're not talking about olive oil, we're not talking about coconut oil, we're certainly not talking about butter.

Dr. Cate Shanahan [00:10:34]: So, the way they are processed is unique. And that's really the problem. Because the processing strips the antioxidants and generates the toxicity that causes oxidative stress in our bodies. The toxins promote oxidative stress. Most toxins actually harm us through oxidative stress. Glyphosate does, and heavy metals do. So these toxins are similar in that regard. It's just that they came from not the seeds themselves, but the reactions that occur during the processing of the oil.

Dr. Cate Shanahan [00:11:16]: So that is only the oils that we need to worry about. It's not the seeds.

Ben Greenfield [00:11:20]: Okay? So the processing is going to reduce the natural antioxidant contents of the oil. Because if you think about extra virgin olive oil, it's got this chock full of these flavanols and polyphenols and antioxidants that would theoretically cause that oil to be stable and less prone to oxidation. But what's going on with vegetable oils, in terms of the way they're processed, that would either increase the amount of toxins in them or decrease their antioxidant content?

Dr. Cate Shanahan [00:11:51]: So what's happening is during the factory refining of these oils, the reason these oils are problematic is because the refining of the creation, the generation of these oils, requires heat. The polyunsaturated fatty acids in these seeds are exposed to extreme heat pressure and oxygen in the factory. And the crude oil that you get from, like, just creating, you know, converting soybeans into soy oil requires lots of heat, and it damages the polyunsaturates, so that the crude soy oil, for example, is disgusting. It's crude and rude. Right. Deserves the term crude. That's different from olive oil, which you just squeeze some olives with a stone press. Could have done that a thousand years ago, and they did.

Dr. Cate Shanahan [00:12:45]: And that oil is edible. That's called virgin olive oil. It is edible and it's good for you. But the soy oil and the corn, the canola, etcetera, the virgin oil is inedible. It's just like burnt, basically. And the proteins the carbohydrates and the fatty acids have all combined in a disgusting, gloppy mess. It's just burnt to seeds, really. And that there's all kinds of stuff in there that is foul smelling and acrid.

Dr. Cate Shanahan [00:13:16]: Like, has an acrid quality. So it kind of can burn your eyes. And if you were to swallow it, it would burn your esophagus in your stomach, and you probably just throw it back up. That's your body's way of protecting itself from these toxins. And it also has toxic compounds in it. And the refining, it requires refining to make it edible. Right? So there's nothing else in the food supply that is inedible and toxic as part of its manufacturing. Nothing else.

Dr. Cate Shanahan [00:13:45]: That's why vegetable oils are oxidative stress in a bottle. And oxidative stress is death, early death.

Ben Greenfield [00:13:52]: Is one of those toxins. I've heard people talk about this one. I think it's hydroxynonenol or something like that. Do you know this one?

Dr. Cate Shanahan [00:14:02]: Yeah, it's 4-HNE. That's just the name of the molecule. It belongs to a family of very toxic compounds called alpha-beta unsaturated aldehydes. Acrolein, or acrolein is another one. Crotonaldehyde from cigarette smoking is another one. In fact, when you use these things to cook in a restaurant situation in a deep fryer, Scientists have tested the amount of toxin that develops, so they can tell you how much you're getting when you eat fries from a place like McDonald's or Burger King. And they found that the amount of these alpha beta-unsaturated aldehydes is equivalent to the amount in a cigarette, on a one-to-one basis.

Dr. Cate Shanahan [00:14:52]: One french fry equals the toxicity of smoking an entire cigarette. So if you give these to your children, it's like giving them cigarettes. And, you know, it's really. I'm not saying this to, like, blame parents or put shame on any parents. It's a shame on the folks who've been claiming that these oils are heart-healthy and promoting them without any regard to the reality of their chemistry and what the toxicologists have been trying to warn for decades.

Ben Greenfield [00:15:22]: What if you just took a bunch of antioxidants?

Dr. Cate Shanahan [00:15:25]: Yeah, that's a great question. It doesn't work. So, like, most of the antioxidants that we can eat are designed by plants, for plants. They help plants, and they help us protect plants from UV radiation and, you know, problems that plants face. Oxidative stress from being dehydrated, for example, and pathogens for plant pathogens. So it has nothing to do with the human body's needs. And the antioxidants that we get from plants, once they get absorbed into our body, they have almost no function. And our liver and kidneys basically need to eliminate them.

Dr. Cate Shanahan [00:16:00]: So while they are useful in terms of cooking, like olive oil, the polyphenols in olive oil, it helps to protect the oil while you're cooking it. It also helps to protect the food that you're cooking in your olive oil, but so it helps to prevent oxidation reactions in your food. It also probably helps to prevent them in your gut, helps keep your microbiome from experiencing too much oxidative stress. But in terms of protecting your cells, they're worthless.

Ben Greenfield [00:16:29]: Have you ever heard of this guy, Doctor James DiNicolantonio, who's written a few food and science books, who says that there are certain things, and two that he names that I know are spirulina and glycine, and that those can somehow help to protect the cell membranes against some of the damage from oxidized oils. This is something I came across in his book, and I believe this was in rodent model studies, that there was less oxidative stress in response to consumption of vegetable oils with around five to 6 grams of spirulina or glycine consumption. I just wasn't sure if you'd come across that at all.

Dr. Cate Shanahan [00:17:11]: I've seen so much about how this or that little thing that can be turned into a supplement helps, and sure it can, but you have to look at the details to understand what they are comparing it to. Are they comparing it to the standard rat chow, which is basically pure processed food? I mean, rat chow, a standard lab animal chow is basically like feeding people vegetable oil, sugar, refined carbohydrates, and protein powders, and then some added vitamins. So this is why it's important to, like, think about these studies. You can't just take them as like, oh, therefore this means that, right? You have to, you have to approach any question from multiple angles. You can't just take one single study and say, it showed it. It must be true. And that's what I've spent my entire career doing. So I always fact-check everything.

Dr. Cate Shanahan [00:18:02]: And I also, like, probe the question from different angles. Like, for example, what are they comparing it to? What are these rats eating? What is the baseline diet? And so if you add a whole food, spirulina is just, it's a seaweed. So I consider that a whole food. So if you add a whole food into a diet that is purely processed junk, it's going to have benefits, but that's all there is to it. So it's not like you need that, right? It's not like you need spirulina to have any special properties. Any whole food has some antioxidants that, like I say, can be helpful during the cooking process, during the digestive process. But then that's where their utility ends. They do not magically help us recover from a lifetime of vegetable oil consumption and processed food consumption that has promoted metabolic disease.

Ben Greenfield [00:18:57]: You talked about how olive oil is processed with less heat. A company like Whole Foods says that they use something like cold expeller pressed canola oil in, like, their salad bar or some of their ingredients. Is there a way to somehow have that oil extracted from, what I think is called the rapeseed, and have it not have as much oxidation, kind of like whole foods is claiming to do?

Dr. Cate Shanahan [00:19:23]: Yeah, so they're kind of misleading you there in a very important way. And they're kind of, they're mixing up expeller pressed with cold-pressed. There is no industry standard term in canola as there is in olive oil. Cold-pressed does refer to a specific temperature in the olive oil world, but to my knowledge, it doesn't. And what they do use, I know what they use, is just your standard expeller pressed. And as I explained actually in the introductory chapter on Dark Calories, that is a big lie. That expeller press organic just means they didn't use hexane. But, everything I said about how crude oil is toxic and needs to be refined in order to become like something that you don't immediately throw up to become edible still applies.

Dr. Cate Shanahan [00:20:16]: So of course they would mislead us. They want us to think that they're doing something great, but it's not great.

Ben Greenfield [00:20:21]: Interesting. Okay, so there's one thing I was thinking about as you're explaining oxidative stress. I'm curious if you agree with me on this. We should probably clarify that you would be referring to excess oxidative stress because, like, I know that you exercise and I exercise, and a lot of people do sauna or they'll have certain xenohormetic agents from plants and herbs and spices. Some people will have a glass of wine at night. Like, all of these are mild forms of hormetic oxidative stress. You're not saying that all oxidative stress is bad. What you're referring to specifically is the type of irreversible cell membrane damage and biological impacts from the type of oxidative stress that's found specifically in processed vegetable oils.

Dr. Cate Shanahan [00:21:13]: All oxidative stress is potentially bad. And don't be confused by the fact that some of it has adaptive benefits. That's just us adapting to this, this danger of metabolic, of oxidative stress. But what I'm referring to is the uncontrolled, like, excessive oxidative stress that is when we have., where it causes dysfunction. Right. And so there isn't a term to describe when oxidative stress goes from the expected normal amount that our biology is capable of handling to not. Right, but that's where diseases can occur.

Dr. Cate Shanahan [00:21:54]: And so the more that you expose yourself to oxidative stress, the more diseases you're going to get. But it is oxidative stress that eventually kills us. So if we could just evaporate the reactions that cause oxidative stress, there wouldn't be any. We wouldn't die. We wouldn't die in 100 years. It would take a lot longer, like, theoretically, right? Like it's an experiment that you just can't run, but that's what I would guess.

Ben Greenfield [00:22:22]: Okay, so tell me if I'm thinking about this the right way. You know, this whole, like, mitochondrial free radical theory of aging would dictate that certain amounts of oxidative stress cause an endogenous antioxidant response, you know, such as sane, reasonable amounts of exercise. And that endogenous antioxidant response winds up, in the long run, protecting you against lifestyle and stress-based oxidative stress that allows exercise to have this life-extending effect when done in moderation. But what I'm thinking about here, and this is at least the way I'm processing this, as you're talking the oxidative stress from something like vegetable oils, unlike exercise, is introducing a compound into the body that is not only causing oxidative stress, but that is sort of being used as a building block for cell membranes and components in the body that would dictate that you're creating a biology that's more susceptible to damage without actually sparking something like endogenous antioxidant production or something like that.

Dr. Cate Shanahan [00:23:40]: Yeah, you can look at it that way, but that, I think, is more complicated than the way I look at it. And so the way I look at it is exercise is healthy for a variety of reasons. And exercise, you know, one of the things that it does is it increases blood flow and it stimulates hormone release. But it's not all through, you know, oxidative stress. There's multiple things going on here. And if we look at it again, we can't look at all of life through the lens of just one process. And oxidative stress is extremely important to understand, but there's other things going on. And so exercise is essential for health.

Dr. Cate Shanahan [00:24:20]: You really cannot be healthy if you never exercise. So it's not because of the oxidative stress, it's because of the other things that are possible for our bodies to accomplish due to exercise, like muscle growth and the generation of necessary blood vessels and the generation of necessary hormones. So for optimal health. Right. So that's how I look at it. And so that exercise, yes, it generates oxidative stress, but we can handle it when our metabolism is healthy, when our diet is healthy, we can handle the oxidative stress from exercise. And, in fact, we don't generate that much because we have so many more. One of the things that exercise does is increase the expression of these antioxidant enzymes and all these important compounds.

Dr. Cate Shanahan [00:25:20]: So we actually, when we're healthy, exercise doesn't cause that much oxidative stress. And this kind of jumps us to another topic. I want to get into this because this is so important, and the topic is insulin resistance. So can we shift gears onto that? Because this has to do with exercise and the population that we're studying and the conversation we're trying to have here.

Ben Greenfield [00:25:40]: Yeah, for sure.

Dr. Cate Shanahan [00:25:43]: Great. So our entire population is insulin resistant today, and it has been since the 19. Well, since the late 1900s. Late 1900s, yeah. More than 90% of the population has been insulin resistant. According to the latest data, which is already about eight years old, 99 plus, less than 1% of the population is normally insulin sensitive. What does that have to do with oxidative stress? Well, in Dark Calories, I explain that oxidative stress is the root cause of insulin resistance. So that's how it's connected.

Dr. Cate Shanahan [00:26:22]: Our diet has given us insulin resistance, and it's not the consumption of carbohydrates that did it. It's mostly the consumption of vegetable oils. And that's why you can have people on extremely high carbohydrate diets that are perfectly healthy. And so because the vegetable oils in our food supply have, like, quadrupled in just the past three decades, so many people are eating too many. Almost everybody's eating too many. They can't possibly be metabolically healthy, and they are not. And so these studies on athletes are studies. You have to consider this.

Dr. Cate Shanahan [00:27:02]: The studies on athletes are studies on people who cannot control oxidative stress normally. And so that's why we think exercise causes so much oxidative stress. But when you're healthy, it doesn't.

Ben Greenfield [00:27:16]: So. So what you're saying is when you're healthy, exercise doesn't cause oxidative stress?

Dr. Cate Shanahan [00:27:21]: Not as much. Right. Not as much. Right. So it's. It's about degree, because the process, mitochondria, as a byproduct of energy generation, they produce free radicals, which promote oxidative stress. It's just unavoidable. That is why we have these antioxidant enzymes.

Dr. Cate Shanahan [00:27:43]: And like I said earlier, we don't have a term or a way to measure when oxidative stress goes from normal physiologic, we can handle it, to too much harmful for the cell. We don't have a way to measure that. We don't have a word for it even. So, it's easy to get confused. And so I'm glad you're asking me these clarifying questions. Keep doing that.

Ben Greenfield [00:28:03]: Okay. Okay. So back to the insulin resistance piece. Most people, if they think of insulin resistance, think, okay, I had too much sugar, too much carbohydrates, my pancreas had to churn out all this insulin to lower my blood glucose. And if that's happening over and over and over again, I've got all this insulin surging around, I develop some kind of cell receptor insensitivity to insulin, insulin resistance sets in, and I become pre-diabetic or Type 2 diabetic. You're saying that that could be a flawed model, or at least not the full explanation for why we're seeing a surge in insulin resistance.

Dr. Cate Shanahan [00:28:41]: I'm actually saying it is a flawed model, and it may have nothing to do with it.

Ben Greenfield [00:28:46]: Okay, can you explain a little bit more about why vegetable oils would be more causative or play a more causative role here when it comes to insulin resistance?

Dr. Cate Shanahan [00:28:58]: Yes. But keep in mind that I lay this all out in detail in chapter three. So I'm just going to kind of hit the highlights here. What the problem has to do with the fact that when our cells are trying to generate energy from our body fat, they can't do it. When we're insulin resistant, they can't generate energy. So that's the reason that people become metabolically inflexible. It's that insulin resistance is also known as metabolic inflexibility. And you're basically in a state where you can build body fat that your cells don't want to burn.

Dr. Cate Shanahan [00:29:37]: When your cells don't want to burn body fat, you get hungry between meals. You don't just get my stomach scrambling hungry. I'm a little bit thinking about food. Normal hunger. You get what I call pathologic hunger. And what everyone now, almost everybody, has experienced it themselves. They call it hangry, but it comes along with brain fog, it comes along with irritability. That is not normal hunger.

Dr. Cate Shanahan [00:30:03]: And that is occurring because your body fat is not a good fuel anymore. Your body fat is too full of polyunsaturates, and your mitochondria just cannot handle polyunsaturates when they are deprived of antioxidant enzymes. That's why understanding antioxidant depletion is just a key piece of all of this. And this is the first book, Dark Calories is the first book to talk about the importance of antioxidant depletion. So that's why I say no one else is really talking about how bad they are for us because they're missing this whole entire half of the puzzle of antioxidant depletion. We can't use our body fat for fuel, so what do we use? Well, what's. There's an alternative, backup fuel. And I bet you know what it is.

Dr. Cate Shanahan [00:30:51]: Glucose. Sugar, specifically. And so what happens? The reason we get hungry is because when our cells are unable to generate energy from our body fat, they become desperate for more fuel. They put receptors for every different type of fuel they can imagine on their surface, and that includes sugar receptors. So they start drawing in blood sugar, but there's hardly any sugar in our bloodstream because we only have 4 grams of sugar in our entire bloodstream. We're not meant to fuel with sugar. Right. That's really important to understand.

Dr. Cate Shanahan [00:31:25]: We're meant to be able to use our body fat. That's why we have it. What else is it for? So we're not supposed to be fueling with sugar between meals? Primarily. We're supposed to be primarily fueling with body fat. But when we are in this antioxidant-depleted state, we need more sugar, we get hungry. We get hungry, we start eating. And what happens? The reason we become insulin resistant. So I've just explained why we get fat.

Dr. Cate Shanahan [00:31:55]: Right?

Ben Greenfield [00:31:57]: And you're saying we get fat because oxidative stress, which can be these days primarily caused by high consumption of processed seed oils, causes a mechanism that, via insulin resistance, insulin, being more of a storage type of hormone, causes adipose tissue to be less able to be broken down for fat. Thus, we maintain fat storage while at the same time experiencing sugar cravings, because we need to get our energy levels up somehow.

Dr. Cate Shanahan [00:32:27]: Okay, so we are not involving insulin yet.

Ben Greenfield [00:32:29]: Okay, yeah.

Dr. Cate Shanahan [00:32:30]: I haven't mentioned insulin yet. Okay, so insulin is not the culprit. Insulin is not, in fact, locking fat in the fat cells. That's why people who are insulin-resistant have high triglycerides. Triglycerides are just the fat in the blood, so there's plenty of fat being released.

Ben Greenfield [00:32:44]: Oh, so. So the fat is being released, but we're not able to actually utilize it for energy.

Dr. Cate Shanahan [00:32:50]: Our cells don't want to utilize it, so they slurp up the other fuels available to them. That includes sugar. And so that lowers our blood sugar, and we haven't gotten yet to insulin resistance. That's why it takes an entire chapter to really get your head wrapped around this. But it's so important because 99% plus people have this. Doctors don't understand it, and they're not going to be able to help you, so you have to understand it yourself as a healthcare consumer. And that's why I wrote the book. So how do we get to insulin resistance? Well, what happens is, as your blood sugar drops, that is a huge stress, and your body starts releasing stress hormones,. What do they do? Raise your blood sugar.

Ben Greenfield [00:33:31]: Right. And they raise your blood sugar, by the way, because something like cortisol would cause glycogenolysis, the breakdown of liver and or muscle storage. Carbohydrates are released into the bloodstream as utilizable glucose.

Dr. Cate Shanahan [00:33:45]: They only break down the liver. You cannot get carbohydrates out of your muscles into the bloodstream. So there's a limited amount of glycogenolysis. The vast majority of sugar, comes from gluconeogenesis, which is the conversion of protein in things like your muscle and your bone into sugar. This is why people are skinny and fat. And I talk about that in Dark Calories, too. I explain skinny fat. So, this model explains skinny fat. It explains why people with Type 2 diabetes and insulin resistance have higher cortisol levels and are in this constant drive of hypersympathetic state, and why they have elevated heart rates, which they do.

Dr. Cate Shanahan [00:34:22]: Why they have elevated blood pressure, which they do. It explains so many of these observed phenomena that no other model explains. It's a revolutionary idea, and I just want to help as many people as possible to understand it so that we can start talking about it. Insulin resistance and obesity, in a logical way that is scientifically supported. So. But getting back to insulin resistance, we still. I still haven't explained why is there insulin resistance. Well, let me tell you right now, what's happening is the brain is telling the liver to do more glycogenolysis to raise the blood sugar. The brain is telling the liver to raise blood sugar through glycogenolysis.

Dr. Cate Shanahan [00:35:01]: And gluconeogenesis raises the blood sugar. But that elevated blood sugar, the pancreas hates it. So the pancreas is releasing insulin. So the liver is getting two conflicting signals. One is coming from a hormone, which it can ignore, and one is coming hardwired in from the vagus nerve and the stress hormones, which it cannot ignore. Right. So, between insulin and stress hormones, which one's more life-threatening? Stress hormones. And so that's what it can't ignore.

Dr. Cate Shanahan [00:35:27]: So the set point of glucose is elevated, and that's what. That's when we start diagnosing pre-diabetes when somebody's fasting blood sugars are over 100. No one can explain why that's happening. A lot of people just say, oh, well, insulin wears out the system, or some nonsense like that. But that is not a scientific explanation. Doesn't explain half the things that we just talked about. So that's why I'm saying that we need a new model. This is the model.

Ben Greenfield [00:35:50]: Interesting. Okay, so, if I've got the ability to still be able, even in a state of oxidative stress and vegetable oil consumption, to be able to have triglycerides in my bloodstream from fat that I've broken down, there's something going on in the cell that is reducing my ability to be able to burn those fats. What is it about vegetable oils that they're doing to the cell that reduces its ability to be able to burn fats?

Dr. Cate Shanahan [00:36:20]: Yeah. It's that they've changed the composition to two things. They've changed the composition of our body fat so that between meals, our cells are exposed to too much PUFA, which damages mitochondria in and of itself, independent of the other thing that vegetable oils do, which is their toxicity, depletes our antioxidant systems so that we cannot, that our mitochondria do not, are really, really susceptible to oxidative stress when they try to burn our body fat, which has more PUFA now. So our cells need an alternative, and the alternative is sugar or even, like, small amino acids. Right. So protein. We start burning the protein from our diets.

Dr. Cate Shanahan [00:37:10]: We start burning any protein that we might release from exercise. What you're doing right now, as your muscles might be releasing a little bit more of certain amino acids into the bloodstream, well, those also can be used for fuel. And this is what we see. This is what we see in people who are insulin resistant, that they've got upregulated glucose transporters and upregulated, I forget the abbreviation. I think it's like something like MCT, small molecule transporters, to import some of these small amino acids that they can also use for fuel.

Ben Greenfield [00:37:43]: Okay, so when it comes to the mitochondria, the impairment of the mitochondria to be able to produce energy adequately from fat, is it something about the structure of these damaged PUFAs? Like, are they actually being used? Because, you know, I've often heard this, you know, you are what you eat and that, you know, the seed oils will stay in the body. I used to hear for three months. Now I hear up to two years. Are they somehow being used to make up the actual internal biological skeleton of your body in some way that reduces mitochondrial energy production?

Dr. Cate Shanahan [00:38:18]: Well, there's a lot of moving parts here, and so you actually, your question actually is several separate questions. And so, like, even just that question could take an entire hour to answer it in detail. And, you know, ideally, I would have slides just for that question. So there's a lot of moving parts, and no one is talking about them. So you've asked a really good question, but it's, you know, some of the things that you said are true, like the fact that our body fat composition is more polyunsaturated. Other cells of the body do not change that much. But our body fat, because it's directly stored vegetable oil, it's where it gets stored, right? Where we eat fat, we store it in our body fat.

Dr. Cate Shanahan [00:39:08]: So that's going to match the composition of vegetable oil eventually. The more that we eat. And that's only part of the problem. The other part of the problem is the toxicity of the foods that we eat because we're cooking with vegetable oil.

Ben Greenfield [00:39:25]: Because the vegetable oils, regardless of what they might be being used to fry, even if it's the healthiest foods on the planet, based on the way that they're processed and extracted, those vegetable oils themselves contain toxins.

Dr. Cate Shanahan [00:39:37]: Yes. So there are two components. It's changing the composition of our body fat. Other people are talking about it, changing the composition of our other cells. It's not really that big of a problem, actually, that they do that. The biggest problem is changing the composition of our body fat by a factor of up to ten times more PUfA than ever, but also depleting our antioxidants. And I keep coming back to that because that is key. And, you know, free radical biology was first.

Dr. Cate Shanahan [00:40:09]: Free radical biology is where we get the free radical theory of aging and disease. And the mitochondrial, it's been out for a long time. It's an entire field of medicine.

Ben Greenfield [00:40:20]: Yeah, since the sixties.

Dr. Cate Shanahan [00:40:21]: Yeah. And so what they've been overlooking this whole time, sadly, is that when we deplete our body's antioxidant stores, that's what brings on disease. What they've been focusing on is supplementing with antioxidants. Exactly the question that you asked. It's a great question, but it hasn't worked. And after 70 years, they gotta stop going down that dead end and turn around and look at what's in the food supply that's depleting our antioxidants and making it so hard for us to control the normal amount of oxidative stress that we get from energy generation. In my other book, I explain how that causes thyroid disease.

Ben Greenfield [00:41:10]: You bring up a really good point, too, because when they first theorized that free radicals caused excess aging, there were multiple studies that were done after that, starting as early as the sixties, in which they administered antioxidants. I don't know if there were any human models involved, but they definitely made it as high up as rodent models. And they found that supplying antioxidants in a state of oxidative stress didn't improve lifespan. And so then you move on to studies in athletes, and you've probably seen many of these, that taking antioxidants post-exercise can even suppress the ability to be able to beneficially respond to exercise. So there's something that seems to be different between supplementing with antioxidants, which I don't think is a bad idea, like eating a diet rich in flavanols and polyphenols and a nutrient-dense rainbow of colors. But there seems to be a difference between that and engaging in lifestyle activities that kind of cause the body to increase cellular resilience through its own endogenous antioxidant production, like sunlight and sauna and cold and exercise and, you know, xenorhomatic stress from a wide variety of plants and vegetables, etcetera. Does that kind of make sense?

Dr. Cate Shanahan [00:42:30]: Yes, it's just called biology. And the problem is that vegetable oils assault our biology and so we don't have that normal response anymore.

Ben Greenfield [00:42:41]: We don't have that normal endogenous antioxidant response, correct?

Dr. Cate Shanahan [00:42:45]: Yeah, it's nothing able to step up to the plate in the way that it needs to and control oxidation reactions during exercise unless people like you have been avoiding seed oils and eating a healthy whole foods-based diet for, you know, long enough to replete these biological systems. And I flippantly said, yeah, it's called biology. That's what controls oxidative stress. But I mean, biology needs to be supported with the diet. Everything in our diet helps to support our biology. A key aspect of this is the enzymes that control oxidative stress and all the other compounds, glutathione and all the supporting molecules, the NADH creation and utilization by the appropriate enzymes, and all the stuff that has to happen to help us control oxidative stress in the body. It's impossible on a diet of processed foods. Vegetable oils are the defining feature of processed foods.

Dr. Cate Shanahan [00:43:44]: We got to stop them. So the other four, there's other ingredients that define processed food that I talk about in Dark Calories. And I think maybe we want to just touch on those real quick.

Ben Greenfield [00:43:58]: Yeah, I want to touch on those. But before we touch on those, one last question regarding this antioxidant thing. I'm sure some people are going to ask, has there actually ever been any research that shows, hey, people who consume seed oils actually produce less superoxide dismutase or glutathione peroxidase or any of these endogenous antioxidants?

Dr. Cate Shanahan [00:44:20]: We have researched from two halves of that puzzle, but not putting the two together. So one half is that the more seed oils that we consume, the more it depletes our bodies of vitamin E and glutathione. Okay, but not they haven't studied. These studies were done a long time ago, and they just didn't have the capacity to study these enzymes. And now, so the other half of the story is that we know that people who are insulin-resistant have, often have lower levels of these enzymes. But it's complicated to study that because part of the initial response is the body tries to increase the production of these enzymes, right? And at some point in malnutrition, you get to where they can't do that anymore.

Dr. Cate Shanahan [00:45:06]: So you go up and you have a higher-than-normal amount. We don't know what that is, and that's never been studied, but this is my theory, is that as part of the response to oxidative stress, the body would upregulate it, upregulate the production of these enzymes. That's what they do with every other enzyme. There's no reason to believe anything else would happen. But as malnutrition takes hold, because you just, you can't produce, your diet is a malnourished diet. If you're eating vegetable oils and then all of your metabolism starts being disrupted, you're not able to make key enzymes and intermediates. You just can't manufacture essential things for your cells, and then that's when you're going to see these enzymes being depleted. And so we see that in many people who have insulin resistance and Type 2 diabetes.

Dr. Cate Shanahan [00:45:57]: Yeah.

Ben Greenfield [00:45:57]: I'm glad you brought the four things to avoid because one of them surprised me. One of them surprised me. You tell me what the four are. And if I remember properly from the book, one of them surprised me. Go ahead.

Dr. Cate Shanahan [00:46:07]: Yeah. So it's the four defining features of ultra-processed food. If your food is made with one of these as a main ingredient, you are eating junk food, basically. So it's vegetable oils, the hateful eight, refined flours. Refined sugars and refined processed powdered proteins. And I think that's probably the one that surprised you, right?

Ben Greenfield [00:46:27]: That's the one that surprised me. I mean, it's no secret. Like, I own a company where we have like a, you know, I have a whey on Kion, we make a whey protein. And I remember reading this in the book, and now that it's been like two months since I've read the book, I don't remember the details. Why? Because obviously the vegetable oil piece makes sense. And then it was sugars and what were the other? And then protein powders. What was the other one?

Dr. Cate Shanahan [00:46:48]: Refined sugars. Refined flours.

Ben Greenfield [00:46:50]: Yeah, refined sugars and refined flour kind of make sense. I mean, you already alluded to the fact that glycation may not be as big an issue as oxidation, but it is an issue. Why the protein powder thing?

Dr. Cate Shanahan [00:47:01]: Oh, are you sure you want me to explain it? Maybe you don't want to know.

Ben Greenfield [00:47:03]: I want to know. Yeah.

Dr. Cate Shanahan [00:47:05]: Okay. So just as PUFAs, when PUFAs are exposed to oxygen, they oxidize. Nitrogen also oxidizes very easily. Protein is made of amino acids. Every single amino acid contains nitrogen. And so when, you know, when you take something like milk and dehydrate it or something like whey, because they don't start with milk to make whey protein powder. They've made yogurt. They've got this extra whey now.

Dr. Cate Shanahan [00:47:40]: And whey is more of the liquidy part and doesn't contain as much casein. And then they dehydrate that. Now they've exposed, milk was never meant to be exposed to oxygen. Amino acids in our diet are normally never exposed. They're never bare naked like that. They're always protected by water antioxidants in a whole food. But when you dehydrate whey protein, now you've exposed these nitrogenous amino acids to oxygen, and they will oxidize. That's why some of that's why the amino acids that have two nitrogens, those are the ones that their levels are actually depleted first in some of the whey protein products.

Dr. Cate Shanahan [00:48:28]: But it's not just whey protein powder that I'm picking on. It's especially, I think the worst is the soy protein powders. Like the soy protein that gets added to a lot of processed foods to bump up the protein content. Vegetable, like texturized vegetable protein, is added to a lot of foods that have meat, and ground beef in them because it's a similar texture. And these soy proteins, they've been exposed to this extreme heat because they're what's left after you squeeze the oil out is soy protein. Texturized vegetable protein. At that high temperature, high pressure is often solvents, and then it's further processed and oxidized and heated again. So it's garbage protein.

Dr. Cate Shanahan [00:49:22]: You can't be healthy off of that.

Ben Greenfield [00:49:24]: What you're saying would be like the difference between, say, like, so if I go out to my chickens right now and grab some scrambled eggs and scramble them up and make myself a nice breakfast burrito, versus buying, like, the powdered scrambled egg mix or eating the powdered scrambled egg mix that they use at a hotel buffet.

Dr. Cate Shanahan [00:49:42]: Right. And prisons and schools, like, that's not real eggs that people are getting. Yeah, it's different. It's bad, not good. It's not as good.

Ben Greenfield [00:49:51]: Do you think? And I don't know if you ran into this, is there a way to extract or dry whey and make it into a powder without that amount of heat or oxidation?

Dr. Cate Shanahan [00:50:03]: Well, the less you use, the better. And if you could do it in an oxygen-free environment, which would be very expensive, you'd have to pump nitrogen or argon gas or some other gas in there. Noble gas would be best, then you could do it. That would be very expensive. Probably better just selling milk at that point.

Ben Greenfield [00:50:20]: Well, I mean, I've talked about so many different protein powder companies on my podcast. I'll do a little research on this because I'm curious if there is a way to do it. Probably one of the reasons I asked, too, is Angelo, my partner at Kion, he's super picky about this stuff, and I believe we had a discussion, but, I mean, it's been like four years since we launched the protein, about the extraction methods, but now I'm foggy on it. So I'm going to dig in and go back and do the research, because I'm pretty sure we address this, but I'll let you know Cate, too, what I find.

Dr. Cate Shanahan [00:50:50]: Yeah, I'm curious.

Ben Greenfield [00:50:51]: There's one other kind of, like, burning question, even though I know we're getting short on time, but we can kind of, like, give the basic overview of this. So it's this: cholesterol. So if I'm consuming a bunch of vegetable oils, am I going to increase my cholesterol?

Dr. Cate Shanahan [00:51:08]: You're going to lower it.

Ben Greenfield [00:51:09]: I'm going to lower it, yeah. That's going to surprise a lot of people here.

Dr. Cate Shanahan [00:51:13]: Yes. Only because most people believe cholesterol is a toxin. Cholesterol is a nutrient, and it's an antioxidant. So it makes sense that when you eat foods that will oxidize, that cause oxidative stress, the antioxidant cholesterol will be depleted. And that's maybe one reason why it happens. We know it happens. This has been shown, this is the whole reason that they were promoted as healthy, because of this false idea the American Heart Association has been promoting for 70 years that cholesterol causes heart attacks.

Dr. Cate Shanahan [00:51:44]: That is not true. It's a false idea. It was never well supported. It was always just a theory. And there has not been very much support that ever came in. And most people have said it's a failed theory, it needs to be retired. But the whole idea that vegetable oils were promoted as heart healthy is because they do lower cholesterol levels, but they do it by oxidizing your lipid-protein particles. That's bad.

Ben Greenfield [00:52:07]: Interesting. So it's not that you're replacing saturated fat, a higher cholesterol food, with vegetable oils, your cholesterol is going down. It's because the oxidative stress from vegetable oil is actually depleting an antioxidant in your body, namely cholesterol.

Dr. Cate Shanahan [00:52:22]: Correct. You got it. And also damages the liver. It damages the liver as well. Like these toxins hit the liver the hardest because once they come in from the digestive system, they go straight to the liver and the liver is subjected to all this oxidative stress and has to upregulate its detoxification processes. Can't always do that. But cholesterol is mostly manufactured by the liver. I mean, hugely manufactured by the liver.

Dr. Cate Shanahan [00:52:47]: Right. There's a couple of other cells in the body that do it for transport into lipid proteins. But we're really mostly talking about the liver when we're talking about LDL and total cholesterol levels so that when the liver is damaged, it cannot make this large, complex molecule. Cholesterol is very difficult to make. It's a huge molecule. It's a big, flat molecule. There are so many enzymes involved. And when the liver is busy doing other stuff and being hit by oxidative stress and toxins, it just can't do it.

Dr. Cate Shanahan [00:53:14]: That's why we see less healthy people having lower cholesterol. When you have Type 2 diabetes, your HDL level drops. When you have Type 2 diabetes, your LDL level tends to not be all that high. And certainly, your total cholesterol level is almost universally on the low side. The average person with Type 2 diabetes and advanced metabolic disease, they have low cholesterol, not high cholesterol. The idea that high cholesterol is a disease state is a dangerous idea, and that's why I call it Dark Calories because is actually the idea that cholesterol is bad for our health is the most deadly idea ever invented by mankind, and it has killed billions of human beings and caused untold suffering for many billions more.

Ben Greenfield [00:54:01]: It's crazy. I think snack foods, of course, are one of the big culprits because you see so many vegetable oils and added sugars in those. But I'm just curious. Kind of a fun question. It's probably the last question I'm going to have time to ask you, Cate, but let's say Cate Shanahan is going to travel over to Europe and you got, I don't know, some flight delays. I'm going to wind up being 30 hours of travel, you have to pack your backpack with some healthy snacks, and you want to go by spoil-free. And, you know, I gotta do the whole fasting thing. Just because, you know, you're just not strong enough.

Ben Greenfield [00:54:33]: You can't jocko your way through it. What snacks are gonna go into your bag?

Dr. Cate Shanahan [00:54:38]: Well, the last time I did this, I bought it. I brought tuna canned in olive oil, some peeled carrots, some fermented pickles, and some cheese. That stuff keeps, like, kept for a couple of days, and I didn't even. I mean, it was still good. I didn't even refrigerate it.

Ben Greenfield [00:54:58]: That's pretty solid, and. Yeah. Thank you. I mean, you might. I don't know. I don't want to sit by you on the airplane with the tuna but besides that.

Dr. Cate Shanahan [00:55:04]: No, I. That's it. I ate that in the airport, not in the airplane.

Ben Greenfield [00:55:08]: Yeah. Yeah. For me, if it's a long trip, usually, for me, this is more of a road trip, because when I fly, I'm usually just, like, some ketones and some amino acids. I'm a little bit more, you know, supplement-based, but avocado, sardines, macadamia nuts, I'm good.

Dr. Cate Shanahan [00:55:24]: Yeah, that's good. Like, anything that keeps, you know, anything that keeps. It's healthy. This is not hard. It's really not hard. You could eat nuts. You could eat peanut butter. You know, there's literally a shopping list of foods that you could bring with you.

Ben Greenfield [00:55:40]: So this book, by the way, Cate and I like, scratch, scratch the surface. So it starts off with the poison in your pantry, the all-you-can-eat buffet of chronic disease, the metabolic problem doctors can't see. Fat bodies and starving brains, which is the hangry concept. But she gets deep into the science, you guys. Then the history part. After I read the book, I was talking about my sons at the dinner table, and they were just shocked about this. We didn't even get into this. We don't have time.

Ben Greenfield [00:56:07]: But you guys got to read chapters five through eight. The truth about cholesterol, Ancel Keys, and the dark side of the American Heart Association, the economics of a chronically ill population, and then the reason for hope. And then a lot of good, practical stuff at the end. How to ditch vegetable oils for good, including your tuna. Eating to heal, the two-week challenge, meal planning, and simple meals. You knocked it out of the ballpark with this book, Cate, because, you know, like you said a few times on the podcast is, like, we didn't have time to get into some of the deep, deep science behind these concepts. But if you are listening and you have friends or physicians or, you know, people lurking on your blog, comment section, or whatever really coming down on you for the whole seed oil thing, read this book because you're going to be really well-equipped with a lot more knowledge about why there's such a problem and what you can do about it. And then, folks, if you have questions, comments, feedback, if you know of a lab that wants to run the research study on endogenous antioxidant production with or without vegetable oil, etcetera, all the show notes are BenGreenfieldlife.com/darkcalories. BenGreenfieldlife.com/darkcalories. it's the same as the name of Cate's new book.

Ben Greenfield [00:57:23]: Cate, thank you so much.

Dr. Cate Shanahan [00:57:25]: Thank you, Ben. This is a fun conversation. You made my did you see the smoke coming out of my ears? You were asking a lot of great questions.

Ben Greenfield [00:57:34]: I like to do that. All right, folks, well, I'm Ben Greenfield, along with Cate Shanahan, signing out from BenGreenfieldlife.com. Have an incredible week.

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