Aidan:
Hello and welcome to the Ideal Nutrition Podcast. My name is Aidan Muir and I’m here with Leah Higl and this is episode 175 where we’re going to be answering the question, are seed oils bad for you? In the podcast outline, I wrote a little thing saying we’re gonna have a brief discussion about why we’re talking about this, but I’m gonna start and go a little bit off script by going, Leah, why do you reckon we’re talking about this?
Leah:
I would say we probably wanna do this episode considering how much we see online at the moment around seed oils and I guess the general fear mongering, that is around it, especially in the plant based space. I see this all the time, like even coming from whole food, plant based, no oil. Like for me, that’s where I started hearing about this kind of stuff around seed oils the most. So yeah, that’s kind of what I’m thinking.
Aidan:
Yeah. Like honestly, there’s just a lot of negativity and I think it’s interesting to filter through being like how much is overblown, how much is real? Are there any benefits? I obviously consume a lot of nutrition content and it seems like one of those areas where a lot of people in the evidence-based community are, I suppose you could call it defending seed oils in a way. But it’s also interesting being like, well, if they make content on sugar, it makes it seem like they’re defending sugar as well and all of those kinds of things. I don’t know. I think it’s just interesting. I personally, obviously as a dietitian, I’ve always had familiarity with this and like a broad overview of the research or whatever.
But over the past few months, I’ve just done a deep dive on seed oils to kind of I don’t know, synthesise it all together and try to put out a bunch of content all at once. Cause low key content creation hack, do it all at once. I’ve done podcasts or now doing the podcasts. I’ve done a blog post. It’s pretty comprehensive Instagram post. Anything else? TikTok? I’ve probably done TikTok. I don’t know. Anyway, so let’s start by defining what seed oils are. As you can probably guess seed oils are oils that are extracted from seeds of various plants.
But going a bit deeper, common examples include canola oil, sunflower oil, soybean oil and safflower oil. So if you look on like the back of a bunch of food labels, you will see these pretty commonly. And these oils are typically high in polyunsaturated fats such as omega-6 fatty acids.
Leah:
Yeah, and like realistically, when it comes to seed oils, most of the negativity is specifically in relation to the processing aspect in that these would be considered I guess quote on quote highly processed foods. And I guess moving to another point some people are going to argue the whole omega-6 to omega-3 ratio thing and there that is definitely worth talking through and it’s something that we will come back to but going back to the processing component I think it’s generally worth noting in terms of processing that it is possible to produce seed oils in a less processed way.
Like it’s obviously still going to be processed because you are taking a whole food and making something else out of it. But we can do it in a way where it’s relatively low processing, just like things like extra virgin olive oil, for example. The reason why it’s not super common to do it though, and why most of these products are heavily processed is because of all the downsides that come with not heavily processing it. So it generally makes it harder to sell because we’ve got things like the appearance, texture and smell not being as marketable, I suppose, and a little bit off-putting if we don’t have these kinds of extra processing things involved in making these seed oils.
And then it’s far less cost effective. So even just the price of a more like a less refined version is usually going to be more than what people are comfortable paying for oil. So I guess in terms of the general processing, yes, these are highly processed things and most of the negativity surrounding it comes from that specific point.
Aidan:
So let’s talk about that specifically. We’re going to talk about how they are normally made. This is probably one of the most common comments that I’ve seen on just Instagram, social media in general. And when I was just talking about that, like broad overview, et cetera, I’d never sat down and like got a video up being like, how do you make canola oil? It’s a bit of a boring topic to be honest.
I had always looked at it through the lens of like, I just care what the outcomes show. Like I just care about what the research is, all of those kinds of things. So both of us have looked at YouTube videos and everything like that on how they are made. And it is interesting. The main comment that I’ve seen is sometimes an evidence-based professional will go and do this entire scientific overview of seed oils. And then the comment will be like, yeah, I don’t care. I’ve seen how they’re made. I’m not going to touch that.
Which is why we’re going to talk about this. We’re going to talk through, we’re going to use canola oil specifically, partly prompted by the fact if yo go on YouTube and you’re like, how’s Canola Oil made? There’s like a video with millions of views that goes through everything. And I don’t know, we’ll talk about it.
Leah:
When you showed me that, I was like, that is pretty gross when you think about it, but also so is the backend of a lot of processing of foods.
Aidan:
So yeah, yeah. But we’ll talk through it. And I suppose like being specific on that video, it’s such an interesting video because it’s very positive. The person talking about the process is very positive being like these are really healthy fats and these and then the videos like showing this like disgusting process. We’re to give two versions of the process of making canola oil to give both sides because I think understanding both sides is pretty important when discussing any topic. So we’re going to do one like fear monger version and then one slightly more balanced version.
Leah:
Yeah. So the fear monger version. So if we’re really trying to amp up how quote on quote bad these are or how it can at least looking at the processing. If you’re just looking at the kind of blanket, like just from a, guess a bird’s eye lens, you’re like, okay, yeah, this is, what does this mean for health before looking at any other research?
But essentially the steps are, so the seeds are obviously gathered. So we’re starting from a whole food. They are then heated to extract the oil. This reduces both the vitamin and antioxidant content. It also oxidises a lot of the fatty acids and that’s something you probably will see kind of spoken about on social media in regards to the processing. The next thing is kind of the things that are added that can be a little scary. So a solvent such as hexane is then added to help de-gum the oil and separate it to extract more. And hexane is a known neurotoxin. So if we actually end up consuming it, not great.
And then other chemicals are added as well. So things like sodium hydroxide to kind of continue the processing aspect. So it is more marketable, the taste, texture, smell, all that kind of jazz. The seed oils are also deodorised to reduce that off-putting smell. And this can also mask if it’s rancid or not. Another thing some people will point out as being a bit of a, something they don’t love about it.
And then the oil is bleached. So literally, literally making it a lighter colour. So I guess when you put it like that, that all these chemicals are being added that if we do consume those chemicals, they’re not great for us. It’s being bleached. It’s being refined. We’re losing micronutrient content. It’s like, okay, when we put it like that, it does sound kind of not good.
Aidan:
And in a way, the best bit about that quote on quote fear monger version is technically everything said in there is true. We wrote that out like making it so that technically everything in there is true. But let’s go one step further to be slightly more balanced. So first step, seeds are gathered. Then the heating process, the first part of that occurs and that does reduce the antioxidant and vitamin content. The fatty acid oxidation depends on the duration and temperature of the heating as well as antioxidant content.
So similar to olive oil as well, if there’s a high antioxidant content, it’s a little bit protective against this heating process. A solvent such as hexane is added, but when you see how it’s made, this significantly increases how much oil is extracted. Like if you look at videos, you’ll see it looks like around 30% extra is extracted by doing this. So obviously that reduces the cost of production massively.
So if you were on the company’s side, if you could do that without it having any negative health consequences, kind of makes sense to do that. I could see why somebody would do that. Any of the chemicals that added are removed later in the process. The final amounts are trace amounts at maximum and are considered safe by regulatory agencies, although I can see why people would still be concerned.
The deodorising process is typically done without any chemicals, although it does involve high heat, once again, which leads to the issues we talked about earlier. And the oil being bleached is typically done with components such as absorbent clays and activated charcoals. These are removed at the end alongside all the other chemicals. I’ve seen criticisms mentioned the use of chlorine by multiple people with very large followers on social media. But from what I’ve seen that actually does not seem common at all. Like when I was going through, I couldn’t find an example of it. That doesn’t mean it doesn’t happen, but it seems rare. Bleaching sounds a lot more scary with the use of chlorine than it does with other stuff. And it’s interesting that a lot of people are just like chucking that into the process.
So the balance perspective, it’s good to be aware of, but regardless of how you look at it, you can see why this leaves people a bit concerned versus the alternative of just processing it at a lower temperature of around or just pressing it sorry at a lower temperature of around 40 degrees without any chemicals. If we go back to extra virgin olive oil kind of comparison, extra virgin olive oil is just cold pressed olives. That’s all it is no chemicals are added no high heats added. Technically, you can do the same thing with seed oils. It’s just once you go through all that stuff you just talked about, you can see why a company wouldn’t want to do it that way for a variety of reasons.
Leah:
Yeah, I think when it comes to the processing of things, I think when we look at the back end of how foods are processed, we can often make an argument for why it could potentially be bad. so many chemicals are used in so much processing of so many different foods. It’s just there is like this excess focus on seed oils online at the moment, I feel.
Aidan:
Yeah.
Leah:
So moving away from the processing, let’s talk a little bit more about that Omega 6 to Omega 3 kind of ratio argument. So we have previously talked about this on the podcast in episodes 94 and 95. So not just in relation to seed oils, but just talking about Omega 3 in general and this kind of ratio thing. So we will treat it seriously and we will discuss it as if you hadn’t seen those episodes, if you hadn’t heard it before and kind of go through our general thoughts. So there is an argument that the ideal ratio of omega 6 to omega 3 is a one to one ratio, but people typically consume a ratio between like 5 to 1 all the way up to 20 to 1 in regards to omega 3 to omega 6.
So this particular argument does stem from the idea that our ancestors ate a diet with this particular ratio. So it must be ideal for human health. So it’s rooted very much in that evolutionary thinking, much like paleo and other topics like that. Just suggesting that because early humans diets had this kind of balanced intake that we should inherently replicate what they were doing in the very, very far past.
Where this logic, I guess starts to fall apart is that, well, just looking at historical intake of humans is not exactly evidence for nutrition. makes a lot more sense for us to look at the entire body of evidence and scientific research that we have on things like omega-3, omega-6, seed oils now and base our opinions off of that rather than this evolutionary paleo kind of general component.
So if we look at the research, there is an abundance of evidence to suggest that there are health benefits to omega-3s. Yes, like that’s pretty much non-debatable. Everyone’s like omega-3 is super healthy. We love them, in generally supporting things like heart health, reducing inflammation, improving brain function, et cetera, et cetera. But at the same time, omega-6 is also like essential for overall health, contributes to growth and development, brain function, metabolic regulation.
Even looking at the research of looking at people who eat more like nuts and seeds that are really high in Omega 6, we see a positive correlation between people that consume those foods that are high in Omega 6 and positive long term health outcomes. So if Omega 6 was this like big bad, in regards to fats and we were kind of lumping it in with things like saturated and trans fats, we just wouldn’t see this correlation between foods high in Omega 6 and positive health outcomes like that wouldn’t make sense that wouldn’t happen.
So I think generally there should be an emphasis usually on consuming more omega-3 in like the general diet. Most people could increase their intake of omega-3, but I think just strictly limiting omega-6 is missing the forest for the trees and probably the wrong way to go about it.
Aidan:
I think omega-3 is one of the least controversial things in nutrition, which almost everyone agrees. It’s like, this is a good thing. The first people are to be like, you don’t need to supplement.
Leah:
Totally
Aidan:
But yeah the next thing I want to go through this is a little bit niche I think it once again shows I spend too much time-consuming nutrition content, particularly on places like Twitter slash x where I don’t think anyone else is consuming content but the claim that obesity was rare before seed oils were introduced into the food supply so I want to explore that I spoke with Leah off air probably last time we were recording about there’s these photos where like the classic photo of people at the beach in the fifties and everyone’s a lane.
And then there’s like a caption above it saying something. And the caption that I saw, this was taken before the influx of seed oils. What a caption. Just implying that seed oils are the cause of this. I don’t know if this is worth addressing, but we’re doing a podcast on seed oil. let’s talk about it. Many things have changed since the fifties. Hot take really, I know. But there has been a huge decrease in activity particularly in relation to everyday tasks related to work and home life. That is so obvious that that is going to change energy expenditure by a few hundred calories potentially.
There is also an increase in calorie intake. This is well documented as well. It’s not a huge increase, but it is an increase. You add those two things together over a long period of time and that starts to explain some pretty large differences. We have more access than ever to hyper palatable food, plus food marketing has improved a fair bit as well. I don’t need to use examples, but I’m gonna use some real ones like Uber Eats. They didn’t have Uber Eats in the 50s. It’s so much easier to access food.
And then another example, just because I’m into business, I care about business things. I’m use an example from McDonald’s. McDonald’s obviously have the touch screens now to order stuff. And it’s so interesting that people’s order sizes at McDonald’s has changed or been influenced by these touch screens because of how easy it is for them to use analytics to figure out upsells in terms of you order one thing and then they’ll be like, do you want to add XYZ? And many people have talked about the psychology of being like, if a person at the counter asks you about that upsell, you might say no for a variety of reasons. But if it’s just on a screen, there’s no one on the other side potentially judging you, you might click on it. And because of analytics, they’ve like really identified which upsells are most likely to work. They do that from a business perspective but little things like that change people’s like intake as well.
Bit of a tangent, but it’s food for thought. From another angle, seed oils reportedly make up about seven to 8% of the calories in the American diet. It is obviously hard to confirm that data because self-reported data has issues. And I normally like to focus on Australia specific content, but these are stats I saw for America. I can’t really imagine Australia is that different.
Leah:
So if anything, maybe slightly less.
Aidan:
Maybe slightly less. If I was having to guess, I would agree with that for sure. I do think reducing seed oil intake would indirectly result in a reduction in calorie intake. So there is a bit of an argument to be made on that. There’s so many other angles that I guess we’ll talk about like in terms of what foods are seed oils commonly in like in terms of baked goods, et cetera. But I don’t know. I think it’s just interesting to talk about this being like we can explain the obesity phenomenon through calories, like that’s not a mystery.
Leah:
Yeah, 100%. And I think like once we’ve, we’ve now kind of touched on the three main negative things that are brought up around seed oils, it’s probably worth just going over and being like, are there any positives to consuming seed oils? So our general consensus is that if consumed in moderation in a minimally processed form, there can be some arguments that this could be beneficial to overall health, given that Omega-6 fats are an essential part of the diet.
So for example, even the vitamin E content. So if it’s not destroyed in the processing, the vitamin E content of these particular seed oils can provide health benefits and vitamin E is an antioxidant. So that could be a beneficial component. Things like flax seed oil, for example. So I feel like this is a little bit of a….It kind of stands on its own compared to the other seed oils in that it’s particularly high in omega-3. So it’s a form of omega-3 called alpha-linoleic acid, which is like the parent form of EPA and DHA, which is the omega-3 found in things like salmon, like your fatty fish and seafood.
It’s not necessarily quite as good or amazing as EPA and DHA because it needs to be converted to EPA and DHA in the body and there are a lot of things that impact that conversion process. But even still like omega-3 in any form, like we’ve said, it’s non-negotiable at this point that omega-3, it has positive health benefits even in the form of alpha-linolenic acid. So like a flaxseed oil, for example, absolutely could have health benefits.
There is also the argument that if somebody were to otherwise have a low omega-6 intake, there are or would be benefits to adding it in. So if someone generally had a really low intake of fats, or if we were even, they had a high intake of fats, but it was predominantly saturated fats, and they moved from predominantly saturated and trans fats to having a lot more omega-6 fats, that is still a move in the right direction. That is still a positive transition and can have absolutely have health benefits.
From a an LDL cholesterol point of view, cardiovascular disease point of view, and that’s not a controversial take. So I guess I would just be saying in general that seed oils could have positive health benefits, particularly if you have a low intake of omega-6 or you are replacing things like saturated and trans fats with omega-6. There’s probably also just an argument also to be made around also including a lot of omega-3s at the same time.
Aidan:
Yeah, that last bit with the LDL cholesterol and cardiovascular disease thing is one of the ones that’s more controversial amongst the people who are very anti seed oil. If we look at the data, it says exactly what you just said. But if you look at certain mechanistic arguments that people will make, like they’ll have a different conclusion. What if somebody’s still listening to this like 20 minutes deep into a seed oil podcast and is interested in LDL cholesterol, what I really recommend people do is listen to Alan Flanagan on one of our other podcasts, Insights of Ideal Nutrition, talking about LDL cholesterol and the things you can do with this. Because he puts on like an absolute masterclass going deep into the research in a way that’s like so obvious, pointing at all those things. And even though there’s like some stuff that even in my own reading, et cetera, I was like, I missed a few things as well.
Using a very specific example, I had been looking at research on saturated fat and polyunsaturated fat for LDL cholesterol myself, trying to find really good numbers and everything like that. And then when I listened to him, I was like, this is why I miss some stuff. He talked about how literally like as far back as the 50s, there was many very controlled studies done on saturated fat and polyunsaturated fat, measuring LDL cholesterol, all of these things. And it kind of highlighted this like, I was looking at research mostly in the last 10 years.
And in 2024, people don’t care about this topic because if somebody is dedicated enough to be doing research on this, they would kind of realise that this covering ground has just been covered for decades on end, which is why there’s not as much like tightly controlled research on this topic. I know it’s a bit of a tangent, but I really do recommend listening to that podcast if anyone’s interested in the topic.
Now we are just going to do a bit of a consensus slash interpretation of this topic. So all the benefits of seed oils can be gotten in other ways. For example, even if you need Omega-6, there are many other sources, for example, nuts, seeds, et cetera. In many cases, seed oils are highly processed and low in micronutrients and also high in calories. They are also found in products that fit that description as well. For example, cakes, biscuits, fast food, et cetera. Once again, you can see how that ties in with the obesity stuff I was talking about earlier. That doesn’t sound like something there’s typically a good thing.
And this is one of the hardest parts I found in producing content in this space. When I talk about every point individually, it makes it seem like it’s a really negative topic. That was something I found a little bit conflicting in terms of how I was talking about how other evidence-based creators, it almost seems like they’re defending it. And like I was going deep down this rabbit hole, it’s like, it almost seems like I’m being critical of it. But then I come back to looking at it through the lens of how those same evidence-based creators will talk about sugar. It’s almost like they’re just responding to somebody acting as if sugar is the biggest evil thing that is like destroying the world. And they’re just kind of trying to have a like a balance take.
And that’s kind of how I want to view this as well. So adding a little bit onto that. Although it doesn’t necessarily make sense to go out of your way to add them in large amounts, I think, like some food flexibility is beneficial. It makes sense to not completely be trying to avoid these things because in small amounts, really not a big deal. A large amount of the criticism
is very heavily overblown as well. And another balanced perspective, if they currently make up 7 to 8% of your total calorie intake or more of your own personal diet, I would make a pretty safe wager that reducing intake of them a bit and replacing that with minimally processed nutrient-rich foods would probably be a good decision. But say if your intake was noticeably lower than that, I would say the advantages of food flexibility and potentially some of those benefits of polyunsaturated fats, et cetera, would be a worthwhile trade-off as well.
This has been episode 175 of the Ideal Nutrition podcast. If you haven’t yet left a rating or review, it’s always greatly appreciated for you to do so. Ideally five stars. But thank you for tuning in today.