Muscle for Life with Mike Matthews - Can Seed and Vegetable Oils Ruin Your Health?

Episode Date: December 12, 2022

Refined oils (and especially vegetable and seed oils) have become a big part of the Western diet, and they’re generating a lot of controversy these days. Especially on social media, many people are saying that these oils are one of the driving factors in the large increase in various diseases like cancer, diabetes, and obesity. Do we need to eliminate refined oils from our diet altogether? If we don't, are we imperiling our health and dramatically increasing our risk of various types of disease and dysfunction? This podcast is my evidence-based answer to those types of claims and to the questions that more and more people are asking me these days about these oils. Timestamps: (0:00) - Join my podcast giveaway! www.muscleforlife.show/giveaway (2:16) - What are refined oils? (3:20) - What happens to our body when we eat refined oils? (8:58) - How do refined oils oxidize when you cook them? (11:24) - What are the cardiovascular effects of refined oils? (13:19) - What are trans fat? (15:48) - What is your position on refined oils? Mentioned on the Show: I’m giving away over $1,000 worth of prizes to commemorate the 1,000th episode of Muscle For Life! Join the giveaway here: www.muscleforlife.show/giveaway

Hi, hi, and welcome to Muscle for Life. I am Mike Matthews. Thank you for joining me today to learn about refined oils, vegetable oils, seed oils, substances that have become a big part of the Western diet and which are generating a lot of controversy these days. Many people are saying that these oils are one of the driving factors in the large increase in various diseases here in the West, like cancer, diabetes and obesity. And these people are saying that we need to eliminate refined oils from our diet altogether. our diet altogether. And if we don't, we are going to be imperiling our health and dramatically increasing our risk of various types of disease and dysfunction, especially as we get older. And so this podcast is basically my evidence-based answer to those types of claims and to the questions that more and more people are asking me these days about these oils. Quickly, before we get started, I want to tell you about a special giveaway that I just launched in celebration of publishing 1,000 episodes of this podcast.

1,000. And to commemorate that illustrious milestone, I'm giving away over $1,000 in prizes. So if you want to enter to win some of those prizes, head over to muscleforlife.show slash giveaway, muscleforlife.show slash giveaway. Entering is very simple. You simply have to subscribe to the podcast, rate it, and then submit some information to an email address. It takes a few minutes podcast, rate it, and then submit some information to an email address. Takes a few minutes and you will be entered to win. But wait, there is more because just for entering, you are going to get some free goodies. You are going to get a year's worth of strength training workouts created by yours unruly. You are going to get 40 different meal plans for different people of different

sizes, and you are going to get a special coupon, a special discount code for my sports nutrition company, Legion. So again, head over to muscleforlife.show slash giveaway and enter now. Okay, let's start this discussion with a quick description of what these refined oils are. So when food manufacturers extract oils from plants and plant materials like palm oil, peanut oil, coconut oil, avocado oil, soybean oil, canola oil, and others, they generally use various chemicals and processing techniques to purify that oil. They do that because the crude oils, the oils in their natural state contain different substances that people don't like. They don't taste good. They are less stable on the shelf. They go bad easier.

They don't look as appetizing. They don't smell as appetizing. And oils that go through those processing steps are referred to as refined oils or processed oils. And as I mentioned in the intro to this podcast, a lot of the controversy over these types of oils is centered on vegetable oils and seed oils. So what happens in our body when we eat these oils? So what happens in our body when we eat these oils? As I mentioned in the intro, many people, many influencers in particular, I see a lot of this on social media these days, are saying that over the past century, refined oils from vegetables, nuts, and seeds, like some of the ones that I mentioned, have become a larger and larger part of the Western diet. And during that same period, we have also seen an explosion in diseases like cancer, diabetes, and obesity. Is there a connection? Many of these people say,

yes, not only is there a connection, this is one of the primary causative factors. How true is that? Well, my position is, yes, there is a connection, but it's not what many ancestral eaters would have you believe. Namely, the bulk of scientific evidence shows that in most cases, refined oils are not unhealthy per se by themselves, but a diet that is rich in refined oils is unhealthy and can lead to health problems. So that's my position. And now I'm going to break it down. Let's talk about different elements of what I just said. Let's start with refined oils and the omega-6 to omega-3 ratio, because this is something that is often claimed as irrefutable evidence of how unhealthy these oils are. So when refined oils became more readily available at the

beginning of the 20th century, food manufacturers began to use them to prepare many different types of prepackaged convenience foods like crackers and biscuits, cookies, pastries, pies, mayonnaise, margarine, and so forth. And because of that, people started to consume more and more of these refined oils, far more than ever before. And since vegetable oils typically contain more omega-6 fatty acids than omega-3 fatty acids, which just refers to the structure of the fatty acid, the amount of omega-6 fatty acids in the standard Western diet skyrocketed. For instance, research conducted by scientists at the Center for Genetics suggests that for most of human history, we consumed roughly equal amounts of omega-6 and omega-3 fatty acids, so a ratio around one-to-one.

However, since vegetable oil intake has increased dramatically starting about 120 years ago, that ratio is now as high as 20 to one with many people, not all people, of course, but with many people in favor of omega-6 fatty acids. And some researchers have theorized that that imbalance between omega-6 and omega-3 fatty acids contributes to chronic inflammation, which underlies many common Western diseases, including cardiovascular disease, type 2 diabetes, irritable bowel syndrome, macular degeneration, rheumatoid arthritis, asthma, some cancers, and even psychiatric disorders. The problem with that theory, though, is the current weight of the evidence doesn't support it. There are several systematic reviews of large numbers of studies,

for example, that have found no link between omega-6 and omega-3 consumption and increased systemic inflammation. In fact, in one study that was conducted by scientists at Maastricht University Medical Center, researchers found that when participants ate meals high in omega-6 fatty acids, they had lower levels of inflammatory markers in their blood than when they ate meals high in saturated fat. Therefore, there is no strong evidence-based argument that you can make for singling out omega-6 fatty acids as the problem and that ratio between omega-6 fatty acids and omega-3 fatty acids. What other research suggests, though, is the absolute amount of omega-3 fatty acids matters greatly. And a diet that is very rich in omega-6 fatty acids and also provides enough, at least

omega-3 fatty acids, is perfectly healthy. But one which is rich in omega-6 fatty acids and provides very little omega-3 fatty acids is unhealthy. And again, the key there, though, is the absolute amount of omega-3 fatty acids. For example, studies show that we need to have, on average, about 500 milligrams of EPA and DHA to omega-3 fatty acids that you find in fish, for example, or a fish oil if you were going to take a supplement, just to maintain our health. That is for basic health needs. And if we want to experience some of the other benefits that higher intakes of EPA and DHA can confer related to inflammation, possibly performance, then we need to take quite a bit more, up to maybe about three grams of EPA and DHA

per day. And so then, instead of telling people to simply eat less omega-6 fatty acids, it would be far more helpful to encourage them to eat enough omega-3 fatty acids and to just consume a variety of healthy foods that are rich in different types of fatty acids. Three, six, nine, eat salmon, eat mackerel, eat anchovies. If you can do it, eat walnuts. That's my choice. I'll take the walnuts over the anchovies, eat almonds, cashews, eat avocado, eat olive oil, put it on your salads, cook with olive oil or avocado oil if you want to be exotic. Okay. Now let's talk about refined oils and oxidation. Another common charge leveled against refined oils is how they oxidize when you cook with them and how bad that is for your health. And so what is oxidation

exactly? Well, it is simply a chemical process whereby substances in the refined oils react with chemicals in the moisture and air, and the change that occurs might be harmful to eat. There's research that shows it is, that consuming repeatedly heated vegetable oils in particular, so you have these vegetable oils that are superheated, usually it's for frying food, and then they are superheated again and again and again. There is evidence to show that eating foods that are cooked in those oils can be bad for our health. But then there are studies that show otherwise, there are studies that show that there are no obvious negative consequences despite the increased oxidation. And given the conflicting evidence, I think it's reasonable to follow the

guidance of a 2015 review published in the British Journal of Nutrition. In this study, the researchers concluded that cooking with vegetable oils is probably safe, but it still makes sense to minimize oxidation. So don't superheat the oils, don't heat them to very high temperatures, and don't reuse them. Now, of course, it's worth noting that if you are eating a healthy diet, which means most of your calories are coming from relatively unprocessed nutritious foods, you are not going to be doing much frying of anything. You're not going to be superheating vegetable oils because you only do that to fry foods. But if you do like to make some homemade fried whatever now and then,

and for whatever reason, you do not want to air fry, which would be my recommendation. If you really like fried food, get an air fryer. But let's say that there's a recipe that requires frying something in vegetable oil. I'm going to guess this is not something that you could or would even want to eat every day. It might be your weekly treat meal, for example, or maybe not even that often. It's okay. You can enjoy it guilt-free. All right, let's talk about these refined oils and heart health, which is kind of interesting because aside from being cheap and readily available, one of the reasons they are popular is they have been associated with improved heart health. So for decades now, public health officials have recommended substituting saturated

fats for polyunsaturated fats because there's evidence that those who do that will suffer fewer cardiovascular related problems. However, the studies that support that evidence tend to be observational in nature, which means that they can show two things are associated, but not that one causes the other. And this is important to know because there are many other factors that contribute to heart health. Many other components of our lifestyle, our physical activity levels, our stress levels, our sleep and other dietary habits. So I don't think that there's good evidence that polyunsaturated fat, like what you'll find in vegetable oil or seed oil,

is better for maintaining your heart health than saturated fat. And to back that claim up with some evidence, there are a number of meta-analyses of randomized controlled trials that have shown that switching to vegetable oil does very little to improve your heart health or your risk of dying from cardiovascular complications. And so I would not recommend swapping saturated fat for polyunsaturated fat entirely. Instead, I would recommend getting a mix of both in your diet. I also recommend limiting your saturated fat to no more than 10% of your daily calories because a large body of research shows that in many people, too much saturated fat increases LDL cholesterol levels, which is the bad cholesterol that increases your risk of heart disease. Okay, now let's talk about refined oils and trans fat, which just refers to a certain type of

molecular structure of the fatty acid. We don't need to get into more details than that for this discussion. And you'll find trans fat, that type of fat in nature, you'll find it in meat, in dairy, small amounts. And you can also find small amounts naturally in some vegetable oils. But there is an artificial type of trans fat that forms when refined oils are going through the process of hydrogenation, which makes them solid at room temperature, takes them from liquid at room temperature to solid. And this artificial trans fat is a problem. You don't have to worry about the small amounts of natural trans fat that might be in your diet because you eat some meat, need some dairy, but artificial trans fat you want to stay away from. There is no question

that it contributes to multiple chronic diseases, including heart disease, obesity, cancer, and diabetes. And it doesn't take huge amounts of artificial trans fat to start causing problems. You can cause problems eating what might seem, at least to you, to be a reasonable amount of foods that contain it, which are often junk food, foods that are rich in these partially hydrogenated oils, which is how you'll see them listed on food packaging, also referred to as mono and diglycerides of fatty acids. Sometimes that's the phrasing. And so the foods that contain these artificial trans fats include commercial baked goods like cakes, cookies, and pies, shortening, microwave popcorn, frozen pizza,

refrigerated dough like biscuits and rolls, fried foods, french fries, donuts, fried chicken, non-dairy coffee creamer, and stick margarine. All foods that, again, if you are going to eat a healthy diet, you generally avoid. And also foods that you can completely avoid, even if you like the category. So if you like baked goods, you can bake them yourself, or you can find products that do not contain these artificial trans fats, these partially hydrogenated oils. Same thing goes for any of the other things that i mentioned you don't have to get the unhealthiest version of those foods and that is a good segue for me to summarize my position again my current understanding of the weight of the scientific evidence which is that refined oils themselves

appear to be benign but often the foods that contain a lot of these oils and the amount of calories these foods contain are not benign, especially when they are overeaten or eaten too regularly. Crackers, cookies, chips, baked goods, granola bars, fried foods, salad dressings, mayonnaise, and so forth. So therefore, in almost all cases, a high refined oil diet is actually just a junk food diet, also known as the standard American diet in the scientific literature. And that's a fitting acronym if there ever was one, right? And so the big problem with the SAD diet is not that it has a lot of seed oil or refined oils in it. It's that it starves the body of nutrition and it promotes weight gain. Now, on the other hand, a low refined oil diet is really just a

healthy diet, again, comprised mostly of relatively unprocessed and nutritious foods that nourish the body and support weight maintenance, support a healthy body composition. So as long as you do that, as long as you eat that balanced and wholesome diet, you don't have any reason to go out of your way to avoid refined oils. Well, my friend, that is it for today's episode. I hope you liked it. Thank you for listening. And don't forget to enter my podcast giveaway in case you missed it because you skipped the intro. I understand I normally skip intros too. I am giving away over $1,000 in prizes to commemorate my 1000th episode of Muscle for Life. And to enter to win, you just have to head over to muscleforlife.show slash giveaway. Muscle for life dot show slash giveaway.

And it takes just a couple of minutes to enter. And you're going to get some free bonus goodies for entering. So you will get a chance to win over $1,000 in prizes. Plus, you'll get instant access to some pretty cool stuff that I think you're going to like, including workouts and meal plans and a special coupon code, a special discount for my sports nutrition company, Legion.