Latest / Wellness, Actually with Emily Oster & Perry Wilson, MD / What's the deal with seed oils?

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What's the deal with seed oils? · Wellness, Actually with Emily Oster & Perry Wilson, MD

• 0:00
  Speaker 1: Hi, Perry.
• 0:01
  Speaker 2: Hi, Emily.
• 0:02
  Speaker 3: Perry, did you know that avocado oil is a seed
• 0:06
  Speaker 3: oil because it comes from the seed of the avocado?
• 0:09
  Speaker 2: Oh, actually, no. And I probably should have because we're
• 0:14
  Speaker 2: doing an episode on seed oils. But I thought I
• 0:16
  Speaker 2: assumed it came because avocado like meat is pretty oily.
• 0:19
  Speaker 2: I thought it just came. I thought you just squeezed
• 0:21
  Speaker 2: the meat. Is meat the right term?
• 0:24
  Speaker 3: It's not the right term. But also I have another
• 0:26
  Speaker 3: fun fact about avocados. This is a good cocktail party
• 0:29
  Speaker 3: fact for you.
• 0:29
  Speaker 4: Yep.
• 0:30
  Speaker 3: Avocado seeds are very large and plants that require being
• 0:35
  Speaker 3: reseeded require animals to eat them and poop them out.
• 0:37
  Speaker 3: Like that's how plants work. And when avocados first existed
• 0:43
  Speaker 3: in the Mesoamericas, there were these giant animals, like 15
• 0:49
  Speaker 3: foot tall animal megafauna. They have names like megatherium and
• 0:53
  Speaker 3: they had these like giant digestive tracts and they could
• 0:55
  Speaker 3: poop out the whole avocado and seeds. They just like
• 0:58
  Speaker 3: eat the fruits and poop out the seeds. But then
• 1:00
  Speaker 3: those went extinct like 13,000 years ago.
• 1:02
  Speaker 2: And avocados- Right around the time that Homo sapiens showed up,
• 1:06
  Speaker 2: just pointing that out.
• 1:06
  Speaker 3: I'm not sure that it was totally our fault, but
• 1:08
  Speaker 3: I think we played a role. And then avocados almost
• 1:12
  Speaker 3: went extinct before people discovered how delicious they were and
• 1:16
  Speaker 3: started cultivating them. That was like 8,000 years ago.
• 1:19
  Speaker 4: Oh, amazing.
• 1:19
  Speaker 2: Thank you, ancestor humans, for keeping avocados going.
• 1:24
  Speaker 3: We almost have no avocados. but instead we have a
• 1:28
  Speaker 3: lot of avocados. So there you go. And you can
• 1:30
  Speaker 3: make them into seed oil, which is the topic of today.
• 1:33
  Speaker 2: I love when a good plan comes together.
• 1:39
  Speaker 3: I'm Emily Oster. I'm an economist and a data expert.
• 1:42
  Speaker 2: And I'm Perry Wilson. I'm a medical doctor.
• 1:44
  Speaker 3: It's Thursday, September 10th, 2026, and this is Wellness Actually.
• 1:49
  Speaker 2: Because you're getting a staggering amount of health and wellness
• 1:52
  Speaker 2: information nowadays from every source imaginable. And some of it
• 1:56
  Speaker 2: is awesome.
• 1:57
  Speaker 3: And some of it is, well, actually bullshit. Fortunately, we're
• 2:02
  Speaker 3: both people who know how to read studies, how to
• 2:05
  Speaker 3: parse the data, and can tell you what's worth thinking
• 2:08
  Speaker 3: about and what you can safely ignore.
• 2:10
  Speaker 2: But before we dig in, a note that this podcast
• 2:13
  Speaker 2: is for educational purposes and should not be construed as
• 2:15
  Speaker 2: medical advice is We don't know your unique situation, so
• 2:18
  Speaker 2: talk to your doctor for personal health decisions.
• 2:22
  Speaker 3: This week, we're asking, what's the deal with seed oils?
• 2:26
  Speaker 3: Harry and I will give the official smasher pass, and
• 2:28
  Speaker 3: then we'll get to your question of the week. But first,
• 2:30
  Speaker 3: let's do the health news roundup after the break. And
• 2:44
  Speaker 3: now for the health news of the week. Perry, there
• 2:48
  Speaker 3: are a bunch of articles about how a promising heart
• 2:52
  Speaker 3: drug has failed in clinical trials. What happened? And is
• 2:58
  Speaker 3: it something we should have predicted?
• 3:00
  Speaker 2: I mean, this is actually really has sent a shockwave
• 3:05
  Speaker 2: around the cardiovascular community. So the story here is that cholesterol...
• 3:11
  Speaker 2: It has many different subtypes. And some of them, like
• 3:13
  Speaker 2: LDL cholesterol, we know are both associated with heart disease,
• 3:17
  Speaker 2: like heart attacks and strokes, and that if you reduce them,
• 3:21
  Speaker 2: then the risk of heart attack and stroke goes down.
• 3:23
  Speaker 2: So that's true of LDL cholesterol. It is causally associated
• 3:27
  Speaker 2: with cardiovascular disease. Therefore, reducing it changes your risk of
• 3:30
  Speaker 2: cardiovascular disease. That's why statins work. There's another subtype of
• 3:35
  Speaker 2: cholesterol called lipoprotein A, sometimes referred to as LP little a.
• 3:39
  Speaker 2: And the data is completely unambiguous that people with higher
• 3:43
  Speaker 2: levels of LP little a have a higher risk of
• 3:46
  Speaker 2: heart attack and stroke, just like LDL. It's like, looks very,
• 3:50
  Speaker 2: very similar. But it was really a problem because unlike LDL,
• 3:55
  Speaker 2: which can be influenced by lifestyle factors such as diet,
• 3:57
  Speaker 2: LP little a seemed to be entirely genetically determined. It
• 4:01
  Speaker 2: was just like you rolled the genetic dice. That's your
• 4:04
  Speaker 2: LP little a.
• 4:05
  Speaker 3: Sorry.
• 4:07
  Speaker 2: So obviously, the race was on to develop a drug
• 4:09
  Speaker 2: that can reduce LP little a. And Novartis did have
• 4:15
  Speaker 2: one called Pelicasin. And in phase two trials, when they
• 4:19
  Speaker 2: did randomized trials of this drug versus placebo, people's LP
• 4:22
  Speaker 2: little a went down by 80% on this drug. Slam dunk,
• 4:26
  Speaker 2: reducing this level of a subtype of cholesterol.
• 4:31
  Speaker 4: But.
• 4:32
  Speaker 2: That doesn't matter, right? What matters is, does taking the
• 4:35
  Speaker 2: drug actually reduce your risk of heart attack and stroke? Not,
• 4:37
  Speaker 2: you know, does it change this surrogate marker? And of course,
• 4:40
  Speaker 2: we all assumed, of course it will, because we know
• 4:43
  Speaker 2: that LP little a is very strongly associated with these outcomes,
• 4:46
  Speaker 2: just like LDL was. And if we can reduce it,
• 4:48
  Speaker 2: we'll reduce the risk of these outcomes. And you probably
• 4:51
  Speaker 2: see where this is going in a phase three trial
• 4:53
  Speaker 2: of 8,383 people, all of whom had high LP little
• 4:57
  Speaker 2: a and history of heart disease. They were randomized to
• 5:00
  Speaker 2: get this drug, which is a monthly injection versus a
• 5:02
  Speaker 2: placebo injection. And all we know so far is that
• 5:07
  Speaker 2: there was no difference in the subsequent rate of major
• 5:10
  Speaker 2: adverse coronary events, which was the primary outcome of the trial. Like, really...
• 5:16
  Speaker 2: A type of, like, people were so confident in this.
• 5:20
  Speaker 2: And I'll tell you, this enters the wellness space because
• 5:22
  Speaker 2: a lot of direct-to-consumer testing labs will tell you your
• 5:26
  Speaker 2: LP little a level. They'll be like, ooh, it's the
• 5:27
  Speaker 2: new hot biomarker of cardiovascular risk. Like, a lot of
• 5:30
  Speaker 2: people listening who have done that testing will know what
• 5:32
  Speaker 2: their LP little a is. And it turns out, like,
• 5:36
  Speaker 2: does it even matter? So, Emily, like, this is sort
• 5:39
  Speaker 2: of your area here, right? We have a clear correlation
• 5:42
  Speaker 2: between a level and an outcome, but changing the level
• 5:45
  Speaker 2: doesn't change the outcome.
• 5:46
  Speaker 3: Yeah, I mean, it's not dissimilar from something like vitamin D, right?
• 5:51
  Speaker 3: Like within the normal range, you know, above 20 people
• 5:54
  Speaker 3: with higher vitamin D measurements with their blood type have
• 5:58
  Speaker 3: all kinds of better outcomes. And you can change vitamin
• 6:01
  Speaker 3: D by giving people vitamin D supplements. But it turns
• 6:05
  Speaker 3: out that that changing doesn't change any actual outcomes, even
• 6:08
  Speaker 3: though it changes this intermediate marker. And it suggests to
• 6:10
  Speaker 3: us that that marker, probably like this one, maybe is
• 6:13
  Speaker 3: picking up something else. Or certainly that's one explanation that
• 6:17
  Speaker 3: this is a marker of some other aspect of probably
• 6:21
  Speaker 3: genetics in this case or some other bodily feature. And
• 6:25
  Speaker 3: so just moving around the marker, okay, but it actually
• 6:29
  Speaker 3: doesn't move the underlying thing.
• 6:32
  Speaker 4: Yeah.
• 6:32
  Speaker 2: I often think of this as grip strength, which, yeah,
• 6:35
  Speaker 2: clearly people with stronger grip strength have better health outcomes.
• 6:39
  Speaker 2: But if you just took someone and made them train
• 6:41
  Speaker 2: just their grip strength, that doesn't actually do anything, right?
• 6:44
  Speaker 2: It's a proxy. I did look to see, could this
• 6:48
  Speaker 2: have been predicted? And I checked, because you and I
• 6:51
  Speaker 2: often debate about Mendelian randomization as a proxy for causality
• 6:55
  Speaker 2: in an observational world. There have been several Mendelian randomization
• 6:59
  Speaker 2: studies of LP little a, and all of them had
• 7:02
  Speaker 2: suggested that LP little a was causally linked to major
• 7:07
  Speaker 2: adverse coronary events. Now, it is always possible that that's
• 7:11
  Speaker 2: still true, and this drug just may be coronary events
• 7:15
  Speaker 2: through some other process, although now I'm having to invoke
• 7:19
  Speaker 2: some special pleading to maintain the LP little a hypothesis.
• 7:24
  Speaker 3: And just to bring a little economics into it, Novartis'
• 7:27
  Speaker 3: stock price went down by 15% when this came out.
• 7:32
  Speaker 3: So this was a surprise to the stock market, as
• 7:38
  Speaker 3: well as a surprise to the people doing the trial, presumably.
• 7:42
  Speaker 4: Yep.
• 7:42
  Speaker 2: Back to the drawing board, guys.
• 7:43
  Speaker 4: Okay.
• 7:44
  Speaker 2: Moving on. Another example of the wellness actually curse striking again.
• 7:52
  Speaker 2: By the way, Em, I don't know if you noticed this.
• 7:54
  Speaker 2: We got an email. This is not the news item,
• 7:56
  Speaker 2: but normally the wellness actually curse is a good thing
• 7:59
  Speaker 2: because we mentioned people doing nefarious things in healthcare and
• 8:02
  Speaker 2: then they get fired or whatever and that's all good.
• 8:05
  Speaker 2: But a month ago, we mentioned Dolly Parton and now
• 8:10
  Speaker 2: I'm worried that This is all our fault.
• 8:13
  Speaker 3: So- Dolly Parton was such an amazing person that is
• 8:17
  Speaker 3: not the topic of today, but I think just like, wow,
• 8:21
  Speaker 3: what an incredible legacy as a person. So just a
• 8:24
  Speaker 3: note here, like Dolly Parton, we could all aspire.
• 8:28
  Speaker 2: Absolutely. So we apologize if we had anything to do
• 8:30
  Speaker 2: with that, but let's do take credit for this recent
• 8:34
  Speaker 2: example of the wellness actually curse, which is that the
• 8:37
  Speaker 2: Pentagon has rescinded their mandatory testosterone screening for troops one
• 8:43
  Speaker 2: day after issuing the formal guidance for the troops to
• 8:47
  Speaker 2: be tested. So Emily, what's going on with testosterone in
• 8:52
  Speaker 2: the military?
• 8:52
  Speaker 3: I mean, as we said at the time, it doesn't
• 8:55
  Speaker 3: really make sense to do this. There's a lot of
• 8:58
  Speaker 3: unclear reasoning. It seemed at the initial time, like they
• 9:02
  Speaker 3: were suggesting it for everyone, including women, really didn't make
• 9:05
  Speaker 3: any sense. It then seems like they dialed that back
• 9:08
  Speaker 3: to like men over 30, which still.
• 9:12
  Speaker 3: Makes more sense, I guess. But then they published a
• 9:15
  Speaker 3: draft and then they took it down. The links on
• 9:18
  Speaker 3: the page say page not found. They didn't even try
• 9:22
  Speaker 3: for a redirect, which I think is really better practice
• 9:25
  Speaker 3: for your website. They've indicated that the guidance has been
• 9:29
  Speaker 3: temporarily rescinded to allow for updates. And that's where they are.
• 9:36
  Speaker 3: So my strong guess is we will never hear anything
• 9:39
  Speaker 3: about this again.
• 9:40
  Speaker 2: A bold prediction. I like it.
• 9:41
  Speaker 3: Yeah.
• 9:42
  Speaker 1: Okay.
• 9:43
  Speaker 3: So there we go. Let's find out. Our last piece
• 9:46
  Speaker 3: of health news is fun. Yeah, it's good news. It's
• 9:51
  Speaker 3: about pig kidneys. So we have hit a record on
• 9:54
  Speaker 3: a pig kidney transplant. You're a kidney doctor. How excited
• 10:00
  Speaker 3: was the kidney community?
• 10:03
  Speaker 2: No, we are very excited. There are about 450,000 people
• 10:07
  Speaker 2: in the United States on dialysis at any given time.
• 10:12
  Speaker 2: And those are all people with kidney failure. They're committed
• 10:15
  Speaker 2: to dialysis three times a week, all of whom could
• 10:17
  Speaker 2: potentially benefit from a kidney transplant, but we're woefully inadequate
• 10:23
  Speaker 2: in terms of the supply of human kidneys. There's just
• 10:27
  Speaker 2: not enough to go around. So we have to really
• 10:29
  Speaker 2: make careful decisions about who's eligible and who's not and
• 10:31
  Speaker 2: so on and so forth. Xenotransplantation is the idea of
• 10:35
  Speaker 2: putting another animal's organ into a human. And as you
• 10:38
  Speaker 2: can imagine, this is not easy because animals have different
• 10:42
  Speaker 2: DNA and the immune reactions are going to be stronger.
• 10:46
  Speaker 2: But pig kidneys are about the right size for human kidneys.
• 10:49
  Speaker 2: And the science here has advanced really dramatically. So what
• 10:53
  Speaker 2: is happening here is we're not just taking a random pig,
• 10:55
  Speaker 2: like from the slaughterhouse and grabbing their kidney and sticking
• 10:57
  Speaker 2: it in someone. These are specially genetically engineered pigs. They've
• 11:02
  Speaker 2: been CRISPR cast, um, to remove some of the antigens
• 11:08
  Speaker 2: that a human would respond to in a pig kidney.
• 11:10
  Speaker 2: They have humanized kidneys. They appear more human to our
• 11:16
  Speaker 2: immune system than they otherwise would. They are raised in
• 11:20
  Speaker 2: a completely sterile facility. These facilities are crazy. These are
• 11:24
  Speaker 2: germ-free pigs because pigs will have different infectious organisms than
• 11:28
  Speaker 2: humans have. And when you immunosuppress a human, you don't
• 11:33
  Speaker 2: want to give them some weird pig infection that we
• 11:36
  Speaker 2: would otherwise fight off because those things are always terrible.
• 11:38
  Speaker 2: So these pigs are all born by C-section, so they
• 11:41
  Speaker 2: can't be colonized by their mother's vaginal flora. They are
• 11:45
  Speaker 2: in these sterile environments where people are wearing full suits
• 11:49
  Speaker 2: of biohazard suits. So it's like boy in a bubble pigs, basically.
• 11:54
  Speaker 2: They also edit out This just has the worst possible acronym.
• 11:59
  Speaker 2: So in all animals' DNA, there are these things called
• 12:02
  Speaker 2: endogenous retroviruses. These are viruses that in our ancient ancestral
• 12:07
  Speaker 2: history got into our DNA and sit there and then
• 12:11
  Speaker 2: they get passed on genetically, like from one person to another.
• 12:14
  Speaker 2: And most of them never reactivate. Humans have systems to
• 12:18
  Speaker 2: prevent those endogenous retroviruses that live in our DNA from
• 12:22
  Speaker 2: ever becoming active again. We've evolved to those defense systems.
• 12:26
  Speaker 2: But what we don't have defense systems against is porcine
• 12:30
  Speaker 2: endogenous retroviruses, abbreviation PIRVs. So a major problem with pig
• 12:38
  Speaker 2: xenotransplantation was PIRVs because those, although pigs can suppress their
• 12:44
  Speaker 2: own PIRVs from coming out, humans cannot keep the PIRVs
• 12:48
  Speaker 2: from coming out of the pig kidneys. These were genetically
• 12:53
  Speaker 2: edited away, the majority of them. And so an amazing
• 12:56
  Speaker 2: bit of science allowed a human to live with a
• 12:59
  Speaker 2: pig kidney for a record 271 days off of dialysis.
• 13:04
  Speaker 2: And then he finally got, this is a guy named
• 13:06
  Speaker 2: Tim Andrews, finally got a human transplant after waiting that
• 13:10
  Speaker 2: amount of time. So this isn't going to be every
• 13:13
  Speaker 2: single patient on dialysis yet, but the progress has been
• 13:16
  Speaker 2: really tremendous and it's pretty cool.
• 13:17
  Speaker 1: Yep.
• 13:19
  Speaker 3: My question with what you just described, which is totally fascinating,
• 13:22
  Speaker 3: is how realistic is this as a, you know, you
• 13:27
  Speaker 3: said there's 450,000 people in dialysis waiting for a kidney.
• 13:31
  Speaker 3: Is this something where like six of them in a
• 13:33
  Speaker 3: year would get a pig kidney? Like it's a cool,
• 13:36
  Speaker 3: interesting thing you could do, but very unlikely to actually
• 13:39
  Speaker 3: be a meaningful thing? Or is this one step in
• 13:42
  Speaker 3: the direction of, you know, lab-grown kidneys that we could
• 13:46
  Speaker 3: actually replace human kidneys with?
• 13:48
  Speaker 2: I think lab-grown kidneys, the progress hasn't been as fast.
• 13:52
  Speaker 2: Like growing a kidney from scratch, just we can't get
• 13:55
  Speaker 2: that quite right yet. But the pigs are growing the
• 13:57
  Speaker 2: kidneys on their own and they look like kidneys and
• 13:59
  Speaker 2: they're the right shape and they have all the tubes
• 14:01
  Speaker 2: and stuff like that. So I actually think xenotransplantation comes
• 14:04
  Speaker 2: first before lab-grown kidneys.
• 14:06
  Speaker 4: And I.
• 14:08
  Speaker 2: Mean, I'm not going to say every technological barrier has
• 14:10
  Speaker 2: been overcome, but I actually suspect that we will, like
• 14:14
  Speaker 2: we're going to be on an upward ramp of this
• 14:16
  Speaker 2: and you're going to hear about a lot more.
• 14:19
  Speaker 3: Amazing.
• 14:19
  Speaker 2: Pretty cool.
• 14:20
  Speaker 3: That's really cool. All right. That's it for the health
• 14:22
  Speaker 3: news of the week. Now, what's the deal with seed oils?
• 14:28
  Speaker 2: All right. Seed oils. How did we get here?
• 14:34
  Speaker 3: How did we get here? I don't know. I mean,
• 14:38
  Speaker 3: so I think this conversation is so fraught because people
• 14:43
  Speaker 3: have no idea how we got here and they don't
• 14:45
  Speaker 3: even know what question we're asking. So I would say
• 14:48
  Speaker 3: the way people ask this question is, are seed oils bad?
• 14:51
  Speaker 1: Right.
• 14:52
  Speaker 3: To which I would say, well, relative to what? And
• 14:55
  Speaker 3: that is sort of the whole frame here is like,
• 14:57
  Speaker 3: what are you comparing them to?
• 15:01
  Speaker 1: Yeah.
• 15:01
  Speaker 2: We need to cook with fat.
• 15:02
  Speaker 3: And what do you mean by bad?
• 15:03
  Speaker 2: Because if you're not cooking with some form of fat,
• 15:06
  Speaker 2: then you're just not cooking, guys. So yes, seed oil.
• 15:10
  Speaker 3: Versus- We're going to say this whole episode is going
• 15:13
  Speaker 3: to be seed oil versus or within seed oil versus.
• 15:16
  Speaker 3: And I think that's the right way to ask.
• 15:18
  Speaker 2: That means we get to talk about beef tallow, which
• 15:20
  Speaker 2: just was not even in my lexicon until RFK Jr.
• 15:25
  Speaker 3: I guess. For reasons I don't even want to get
• 15:27
  Speaker 3: into this weekend, I was on Amazon looking for something
• 15:31
  Speaker 3: and I came across a product that was a collagen
• 15:37
  Speaker 3: beef tallow face cream. And I was just like, this
• 15:41
  Speaker 3: is all the things. Like I should buy this and
• 15:44
  Speaker 3: put it on my face. So maybe next time we come,
• 15:46
  Speaker 3: I'll have a beautiful face.
• 15:49
  Speaker 2: It sounds like a face with a lot of pimples.
• 15:51
  Speaker 2: I don't know. I feel like beef tallow on your
• 15:53
  Speaker 2: face is not going to keep your pores nice and open,
• 15:56
  Speaker 2: but what do I know?
• 15:57
  Speaker 3: So yes, we will discuss beef tallow as a great
• 16:00
  Speaker 3: alternative or possibly not to seed oils. But the other
• 16:05
  Speaker 3: thing I think people don't understand is like, what is this, right?
• 16:07
  Speaker 3: I asked you at the top of the episode, like,
• 16:09
  Speaker 3: is an avocado a seed oil? Yes, although not everybody
• 16:13
  Speaker 3: thinks that. So there's a hateful eight seed oils. Do
• 16:18
  Speaker 3: you know what they are?
• 16:20
  Speaker 2: I do now. This comes from Kate Shanahan. And these
• 16:26
  Speaker 2: are the seed oils. So canola oil, also known as
• 16:30
  Speaker 2: rapeseed oil, cottonseed oil, soybean oil, sunflower and safflower oils,
• 16:35
  Speaker 2: grapeseed oil, not rapeseed, but grapeseed oil, corn oil, and
• 16:41
  Speaker 2: rice bran. Did I get them all?
• 16:42
  Speaker 3: First of all, I just want to be clear. That's right.
• 16:45
  Speaker 3: This comes from someone whose kind of whole thing is
• 16:47
  Speaker 3: she doesn't like seed oils. Her tagline is that she's
• 16:51
  Speaker 3: standing up to health authorities about seed oils. So she's
• 16:54
  Speaker 3: not a fan.
• 16:54
  Speaker 2: Talk about a niche.
• 16:55
  Speaker 3: Some of these things aren't seeds.
• 16:56
  Speaker 1: Okay.
• 16:57
  Speaker 3: Just to be clear, corn is not a seed oil. Rice, anyway, fine.
• 17:01
  Speaker 1: Yeah, sure.
• 17:01
  Speaker 3: Corn is a grain. Rice is a husk. I don't know.
• 17:05
  Speaker 3: But some of these are seeds. They're seeds. Okay.
• 17:08
  Speaker 2: So seed oil is a misnomer, but the list is
• 17:12
  Speaker 2: the list, right? And you said avocado is a seed oil,
• 17:14
  Speaker 2: but most people don't put avocado in the seed oil category.
• 17:17
  Speaker 2: So this is a vibe more than anything else, right?
• 17:20
  Speaker 2: Seed oils. It's like the cheap, widely available- oils that
• 17:25
  Speaker 2: I can buy in the supermarket or that I'm going
• 17:27
  Speaker 2: to get from a restaurant that's frying stuff.
• 17:28
  Speaker 3: And I think that's the thought, actually, it's useful for
• 17:30
  Speaker 3: people to hold for, like, think about this whole thing.
• 17:34
  Speaker 3: It's like most of these oils are cheap. If you ask, like,
• 17:36
  Speaker 3: what is distinguishing these, it is not as so much
• 17:39
  Speaker 3: the seeds as the price. And these tend to be
• 17:42
  Speaker 3: the kinds of oils you are using in a lot
• 17:45
  Speaker 3: of processed foods, a lot of packaged foods, because they
• 17:49
  Speaker 3: are cheap. And that's going to come up when we
• 17:50
  Speaker 3: try to evaluate their health impacts because of how... price works.
• 17:55
  Speaker 2: Yeah. I mean, we've telegraphed multiple times in Wellness Actually
• 18:00
  Speaker 2: how price signaling always confounds health relationships because rich people
• 18:06
  Speaker 2: get better healthcare, at least in the United States.
• 18:09
  Speaker 4: True.
• 18:10
  Speaker 1: All right.
• 18:11
  Speaker 3: So what these things do share, I think, which is
• 18:13
  Speaker 3: consistent with corn oil, safflower oil, et cetera, is that
• 18:17
  Speaker 3: they have a lot of omega-6 polyunsaturated fatty acids. Sometimes
• 18:24
  Speaker 3: the other word for this is linoleic acid. Am I
• 18:27
  Speaker 3: saying that?
• 18:27
  Speaker 2: Linoleic acid is the- Linoleic.
• 18:30
  Speaker 5: Yeah.
• 18:30
  Speaker 2: Linoleic acid. Let's do some science.
• 18:32
  Speaker 3: It is one of our essential fatty acids.
• 18:35
  Speaker 1: Yeah.
• 18:36
  Speaker 3: Yeah, yeah.
• 18:36
  Speaker 2: Remember when we were talking about supplements and stuff, we
• 18:40
  Speaker 2: talked about essential vitamins and minerals and things like that.
• 18:42
  Speaker 2: By the nutritional term essential doesn't mean like, ooh, great,
• 18:47
  Speaker 2: and part of a healthy diet. It means a substance
• 18:49
  Speaker 2: that you need for survival that you can't synthesize yourself.
• 18:52
  Speaker 2: And there are two essential fatty acids and one is
• 18:56
  Speaker 2: linoleic acid, the major constituent of things like corn oil.
• 19:00
  Speaker 2: If you don't get enough linoleic acid, you die and
• 19:04
  Speaker 2: you can't make it yourself. So you literally like right
• 19:07
  Speaker 2: off the top here, you do need some, you need
• 19:12
  Speaker 2: to get some into your body somehow. I mean, we
• 19:14
  Speaker 2: can argue how much is too much. And I will
• 19:16
  Speaker 2: say that the deficiency states are pretty rare because you
• 19:20
  Speaker 2: don't need a ton of linoleic acid to survive. You
• 19:22
  Speaker 2: just need a little bit. And almost everyone easily gets
• 19:25
  Speaker 2: that through their diet. So we don't see linoleic acid
• 19:30
  Speaker 2: deficiency too much unless people have various GI symptoms. The
• 19:35
  Speaker 2: other essential fatty acid is known as ALA. It's an
• 19:41
  Speaker 2: omega-3 fatty acid. And I think I think we've got it. Like,
• 19:45
  Speaker 2: we're going to get there, but is now a good
• 19:47
  Speaker 2: time to talk about polyunsaturated versus monounsaturated versus saturated fats?
• 19:52
  Speaker 2: Because people are going to need to know.
• 19:53
  Speaker 3: Let's do it. Go for it. Enjoy yourself.
• 19:57
  Speaker 2: Okay. So saturated fat, you've heard that term, and probably
• 20:03
  Speaker 2: because for 40 or so years, saturated fat was at
• 20:07
  Speaker 2: the center of the lipid hypothesis, which was the idea
• 20:09
  Speaker 2: that consumption of saturated fats increased cholesterol and promoted cardiovascular disease.
• 20:14
  Speaker 2: This is almost certainly true. What a saturated fat is,
• 20:18
  Speaker 2: what saturated here means is that the chain of carbons,
• 20:23
  Speaker 2: which is part of the lipid structure, has only single bonds,
• 20:29
  Speaker 2: no double bonds. So it is full of single bonds.
• 20:32
  Speaker 2: Saturated with single bonds, it actually means there's hydrogen sticking off,
• 20:36
  Speaker 2: but it's fine. Just think all single bonds. And the
• 20:41
  Speaker 2: practical upshot of this is that because they're all single bonds,
• 20:45
  Speaker 2: the fatty acids aren't very kinky. They lay very straight,
• 20:47
  Speaker 2: which means they can pack together very tightly. And that
• 20:50
  Speaker 2: means that something that's high in saturated fat is going
• 20:52
  Speaker 2: to be solid at room temperature.
• 20:55
  Speaker 3: Like butter or beef tallow.
• 20:56
  Speaker 2: Butter or beef tallow. If you put a double bond
• 21:00
  Speaker 2: in that long chain of carbons, A single double bond,
• 21:03
  Speaker 2: you get a monounsaturated fatty acid. And like oleic acid
• 21:08
  Speaker 2: is probably our prototypical one there. That's the major component
• 21:11
  Speaker 2: of olive oil. And by putting a little kink in
• 21:14
  Speaker 2: that chain, they don't pack nicely together as much and
• 21:17
  Speaker 2: you get something that's liquid at room temperature. And then
• 21:20
  Speaker 2: a polyunsaturated fatty acid has multiple polysaccharides. double bond. So
• 21:24
  Speaker 2: multiple little kinks, also going to be liquid at room temperature.
• 21:28
  Speaker 2: And as you pointed out, linoleic acid is, you know,
• 21:31
  Speaker 2: a great prototypical PUFA, polyunsaturated fatty acid. And now, you know,
• 21:36
  Speaker 2: the chemistry that explains why beef tallow and butter are
• 21:41
  Speaker 2: solid and olive oil is less so. Although you might
• 21:44
  Speaker 2: note that olive oil, like if you put in your refrigerator, congeals, right?
• 21:47
  Speaker 2: Whereas like, because it's only a monounsaturated fatty acid, but then,
• 21:51
  Speaker 2: you know, sunflower oil won't, I don't know. That's kind
• 21:53
  Speaker 2: of neat. Food science.
• 21:55
  Speaker 3: Food science. So I think it's worth talking about, in
• 22:00
  Speaker 3: some ways, all of the lead up to this. And
• 22:02
  Speaker 3: if you just talked about this, like you would talk
• 22:04
  Speaker 3: about it in a chemistry class, okay, this is a
• 22:06
  Speaker 3: kind of fatty acid. It's something that you need. Without it,
• 22:08
  Speaker 3: you would die. It feels like, all right, cool. Why
• 22:11
  Speaker 3: does Kate Shanahan hate them so very, very, very much?
• 22:16
  Speaker 2: What'd they do to you, Kate Shanahan?
• 22:18
  Speaker 3: And I think part of, for me, I think a
• 22:20
  Speaker 3: big piece of this answer is trans fats. So people
• 22:26
  Speaker 3: in the 50s and 60s get very, people were like
• 22:29
  Speaker 3: very unhappy, maybe like later than this, about saturated fats
• 22:32
  Speaker 3: and were looking for things like margarine. Remember margarine? Margarine
• 22:36
  Speaker 3: was like so good for you. And margarine was full
• 22:39
  Speaker 3: of trans fats. Trans fats turned out to be really
• 22:43
  Speaker 3: bad for you. Trans fats were bad. They did not good.
• 22:47
  Speaker 3: They gave you heart disease.
• 22:48
  Speaker 2: Yep. Pretty clearly. And trans fats are an industrial product. process.
• 22:54
  Speaker 2: You don't really get trans fats from natural sources. The
• 22:59
  Speaker 2: reason margarine works, and Crisco is maybe the first example
• 23:03
  Speaker 2: of this, is that if you get these plant-based fats,
• 23:06
  Speaker 2: the monounsaturated and polyunsaturated fatty acids, they're liquids. And people
• 23:10
  Speaker 2: didn't want to put liquids on their toast, right? They
• 23:14
  Speaker 2: wanted to spread something on their toast. And so what Crisco,
• 23:18
  Speaker 2: what the good people at Procter & Gamble figured out
• 23:20
  Speaker 2: in 1911... is that they could take cottonseed oil, which
• 23:23
  Speaker 2: was a liquid, and they could hydrogenate it to make
• 23:27
  Speaker 2: those double bonds back into single bonds. So they would
• 23:30
  Speaker 2: saturate the unsaturated fat. And that's what hydrogenated vegetable oil
• 23:34
  Speaker 2: or whatever is. That process made Crisco solid and shelf stable, right?
• 23:41
  Speaker 2: So now you've got, instead of a drizzly oil, you've
• 23:43
  Speaker 2: got something you can spread or whatever you want to
• 23:45
  Speaker 2: do with. And margarine was exactly the same. But the
• 23:47
  Speaker 2: process of hydrogenation... by breaking those kinks and making them
• 23:51
  Speaker 2: straight again, made trans fats the way it used to
• 23:55
  Speaker 2: be done. They're now banned, and so you can't use
• 23:57
  Speaker 2: those processes anymore. But this is one of those cases where, yes,
• 24:02
  Speaker 2: it was the processing that caused the harm. And processed
• 24:08
  Speaker 2: foods are potentially bad in some cases.
• 24:11
  Speaker 3: So there was this backlash against trans fats. They ended
• 24:14
  Speaker 3: up being banned. And I think part of that was
• 24:16
  Speaker 3: then people got into, okay, processing in all forms is bad.
• 24:21
  Speaker 3: And then I think that translated to things that are
• 24:24
  Speaker 3: not butter are bad because margarine was a substitute for butter.
• 24:27
  Speaker 3: And so shouldn't we just go back to butter? And
• 24:31
  Speaker 3: that has led us to our current moment where the
• 24:36
  Speaker 3: flipped food pyramid now has beef tallow and butter at
• 24:41
  Speaker 3: the top and other things not at the top. And actually,
• 24:45
  Speaker 3: RFK Jr. is moving towards trying to get seed oils
• 24:48
  Speaker 3: out of school lunches and all kinds of other stuff.
• 24:51
  Speaker 3: So it's like, you know, the trans fats were bad,
• 24:56
  Speaker 3: but that is different from saying that you shouldn't have
• 24:59
  Speaker 3: canola oil.
• 25:00
  Speaker 1: Right, right, right.
• 25:00
  Speaker 2: Yeah, they were taking seed oils, they were messing them
• 25:02
  Speaker 2: up and creating something bad that has now been banned.
• 25:05
  Speaker 2: And now we're saying, oh, therefore seed oils are bad.
• 25:07
  Speaker 2: And we need to evaluate those claims based on what
• 25:10
  Speaker 2: seed oils are today. So let's do that. I think
• 25:17
  Speaker 2: the thing that resonates the most with what we've talked
• 25:20
  Speaker 2: about is the first sort of criticism. And there are
• 25:23
  Speaker 2: a number of criticisms of seed oils, but I think
• 25:24
  Speaker 2: the first criticism is the, it's how they're made. problem, right?
• 25:30
  Speaker 2: The processing. So can I play you a clip of
• 25:34
  Speaker 2: a typical influencer on Instagram talking about the processing of
• 25:39
  Speaker 2: seed oils? What are the most harmful foods that people
• 25:42
  Speaker 2: constantly eat? No question, it's seed oils.
• 25:45
  Speaker 5: The reason for this is that it's not the plant, okay?
• 25:47
  Speaker 5: It's the distance from the plant to the table. When
• 25:49
  Speaker 5: you put a canola plant or a rapeseed, same thing,
• 25:52
  Speaker 5: into a commercial press, it comes out gummy and you
• 25:54
  Speaker 5: degum it with hexane, which is a known neurotoxin. Then
• 25:57
  Speaker 5: you take that neurotoxin degummed oil and you heat it
• 26:00
  Speaker 5: to 405 degrees and you turn it rancid. So it's
• 26:02
  Speaker 5: putrefied and now it smells and you need to deodorize
• 26:05
  Speaker 5: it with sodium hydroxide, which is a very powerful carcinogen.
• 26:09
  Speaker 5: And then you sometimes bleach it before you bottle it
• 26:11
  Speaker 5: and put it on the shelf. You ever notice when
• 26:13
  Speaker 5: you go down the shelf, the aisle and a shelf
• 26:15
  Speaker 5: in a grocery store and it's all the vegetable oils,
• 26:17
  Speaker 5: Wesson oil, vegetable oils, they're all exactly the same color,
• 26:21
  Speaker 5: that beautiful, perfect yellow color. That would never happen. If
• 26:24
  Speaker 5: you pressed a thousand plants and turned it into oil,
• 26:27
  Speaker 5: you would not get that level of consistency. That's chemically induced.
• 26:31
  Speaker 5: And then they put a heart healthy label on it.
• 26:33
  Speaker 5: These are pro-inflammatory. They cause a massive amount of inflammation
• 26:37
  Speaker 5: in the body.
• 26:38
  Speaker 2: So- Emily, this clip has multiple claims, all very scary.
• 26:42
  Speaker 2: And I actually think because these get repeated over and
• 26:45
  Speaker 2: over and over again, I think it's just worth going
• 26:47
  Speaker 2: through them once, talking about the process. And yes, you
• 26:51
  Speaker 2: can't just squeeze a seed as hard as you can. Actually,
• 26:55
  Speaker 2: You could actually.
• 26:56
  Speaker 3: You just wouldn't be very much. It's not as efficient.
• 26:59
  Speaker 3: You couldn't take the seeds and like squeeze them really
• 27:01
  Speaker 3: hard and drip them into your, it would take a
• 27:03
  Speaker 3: very long time. Yeah.
• 27:04
  Speaker 2: But there are companies that are doing cold pressed seed oils.
• 27:06
  Speaker 2: But in any case, the standard way that like your
• 27:08
  Speaker 2: canola oil is getting done is a process thing. So
• 27:12
  Speaker 2: let's walk through it. And I think basically the only
• 27:14
  Speaker 2: thing true that was said in that clip is that
• 27:18
  Speaker 2: hexane is used as a solvent here, right?
• 27:22
  Speaker 3: That sounds right.
• 27:22
  Speaker 1: Yeah.
• 27:22
  Speaker 3: I mean, he did list some seed oils. That seems right.
• 27:25
  Speaker 2: Yeah. So this is true. Oils don't dissolve in water.
• 27:30
  Speaker 2: So if you're trying to extract them from something, you
• 27:32
  Speaker 2: need a nonpolar solvent. Remember chemistry, like dissolves like. And
• 27:38
  Speaker 2: hexane is what is typically used. So that extracts the oil.
• 27:43
  Speaker 2: Then the hexane is distilled off There is potentially some
• 27:47
  Speaker 2: residual hexane in seed oils. The limit is less than
• 27:50
  Speaker 2: one part per million. And then this is just the
• 27:54
  Speaker 2: standard influencer thing is like, I'm going to take this
• 27:58
  Speaker 2: true fact, there's some processing here, and then I'm just
• 28:01
  Speaker 2: going to extrapolate to everything else. So for example, hexane is, oh,
• 28:08
  Speaker 2: it's a known neurotoxin.
• 28:10
  Speaker 3: At some doses, yeah.
• 28:11
  Speaker 1: Yeah, yeah, yeah.
• 28:12
  Speaker 2: If you're sniffing glue, it's a neurotoxin. If you fall
• 28:15
  Speaker 2: into a vat of hexane in a hexane factory, it's
• 28:18
  Speaker 2: a neurotoxin. That's true. But the dose makes the poison, right?
• 28:23
  Speaker 2: Like tiny amounts of stuff your body deals with. You
• 28:27
  Speaker 2: get exposed to all the time through multiple sources. I'm
• 28:31
  Speaker 2: sure you're getting a lot more hexane filling up the
• 28:33
  Speaker 2: gas in your car than you are from your canola oil.
• 28:36
  Speaker 3: This is such a classic wellness influencer conversation. tactic online
• 28:41
  Speaker 3: and really in a huge share of the panic headlines
• 28:44
  Speaker 3: that I deal with, it is just this point that
• 28:46
  Speaker 3: people are saying, well, there's a tiny amount of this
• 28:48
  Speaker 3: thing in something. And if you ate that thing as
• 28:52
  Speaker 3: your primary food, it could cause a problem. It's like, yeah,
• 28:55
  Speaker 3: I get it. Or we fed mice this thing as
• 28:57
  Speaker 3: their entire diet. And that wasn't good for them. It's like,
• 29:00
  Speaker 3: that's actually different than there's a teeny, teeny, weeny amount
• 29:04
  Speaker 3: of it. And those are just not the same. And
• 29:07
  Speaker 3: That's it.
• 29:07
  Speaker 2: They're just not the same. Yeah, the world is... Even
• 29:09
  Speaker 2: natural foods, the world is full of toxins and poisons. Like,
• 29:12
  Speaker 2: we have multiple systems in our bodies.
• 29:13
  Speaker 3: That's why you have kidneys and a liver. Exactly.
• 29:16
  Speaker 1: Okay?
• 29:16
  Speaker 3: That's what they're doing. It's their whole fucking job.
• 29:18
  Speaker 2: Just the way it is. A couple of other errors there.
• 29:23
  Speaker 2: Sodium hydroxide is a powerful carcinogen. Like, that is... That's
• 29:30
  Speaker 2: not true at all. Sodium hydroxide is just a base.
• 29:32
  Speaker 2: We add it to the water supply in areas where
• 29:35
  Speaker 2: the pH of the water is too low, like the
• 29:38
  Speaker 2: water's too acidic, so you add sodium hydroxide. to increase
• 29:41
  Speaker 2: the pH to a normal level of seven or so.
• 29:44
  Speaker 3: So what you're saying is the water is the carcinogen.
• 29:46
  Speaker 2: Is that what I'm hearing? At least hexane, you can
• 29:49
  Speaker 2: be like, yeah, I guess if you sniff a bunch
• 29:52
  Speaker 2: of glue, it's bad for you. But sodium hydroxide... It's
• 29:54
  Speaker 2: just a base. I don't know what that is. And
• 29:57
  Speaker 2: the other thing that the oil is like made rancid
• 29:59
  Speaker 2: by the processing or denatured, that's just also not true.
• 30:04
  Speaker 2: It is extracted under some heat and we will go
• 30:08
  Speaker 2: through what can happen with prolonged frying of oil at
• 30:12
  Speaker 2: extremely high temperatures. That's not what's being used here. So again,
• 30:16
  Speaker 2: just influencers saying stuff that's scary because saying scary stuff
• 30:22
  Speaker 2: gets you to share with your friend and be like, oh, look,
• 30:24
  Speaker 2: you know, this is scary. Maybe we shouldn't use canola
• 30:26
  Speaker 2: oil anymore.
• 30:27
  Speaker 3: Also, the names are like, you know, like sodium hydroxide. Oh, yes,
• 30:32
  Speaker 3: that doesn't sound good. You know, the same, but like,
• 30:36
  Speaker 3: what about sodium chloride? How does that sound?
• 30:39
  Speaker 2: That's scary.
• 30:40
  Speaker 3: That sounds scary. That's salt.
• 30:42
  Speaker 2: Yeah. It's, yeah, you know, this is all sort of
• 30:46
  Speaker 2: the like, processing is bad. And processing is, It's really
• 30:52
  Speaker 2: neither good nor bad. Processing can create bad things like
• 30:58
  Speaker 2: super sugary, easily digestible food that gives us too many
• 31:02
  Speaker 2: calories and makes us fat. Absolutely. But processing in and
• 31:06
  Speaker 2: of itself is not a poison.
• 31:08
  Speaker 1: Yeah.
• 31:09
  Speaker 4: Yeah.
• 31:09
  Speaker 3: I think this is like a sort of legacy of
• 31:11
  Speaker 3: this is legacy in this case of the trans fat stuff.
• 31:13
  Speaker 3: It's also a general legacy of this idea of ultra
• 31:16
  Speaker 3: processing and processing itself as the problem as opposed to
• 31:19
  Speaker 3: what it is processed into. That is more of the issue.
• 31:24
  Speaker 3: All right. The second claim that I think we hear
• 31:26
  Speaker 3: all the time beyond the processing is inflammatory.
• 31:29
  Speaker 1: Mm-hmm.
• 31:29
  Speaker 3: Boy, does a wellness influencer love inflammatory. I mean, good Lord.
• 31:33
  Speaker 2: Where would we be without inflammation? People would be more excited.
• 31:34
  Speaker 3: About being inflamed or not inflamed or like, I'm not
• 31:37
  Speaker 3: even sure if I would know if I was inflamed,
• 31:38
  Speaker 3: but I, for sure, it's probably.
• 31:41
  Speaker 2: That sounds like something an inflamed person would say.
• 31:43
  Speaker 3: It definitely does.
• 31:44
  Speaker 2: I'm pretty sure.
• 31:46
  Speaker 3: I'm pretty, consumed a lot of sodium something yesterday. And
• 31:49
  Speaker 3: so I think I'm feeling inflamed today. So is this,
• 31:53
  Speaker 3: first of all, what does that mean? Do we, do
• 31:56
  Speaker 3: we know? Do we have a sense?
• 31:59
  Speaker 2: Yeah, I think I know.
• 32:00
  Speaker 1: Okay.
• 32:02
  Speaker 2: So inflammation is the process of your immune system doing something.
• 32:09
  Speaker 2: You know, it literally comes from like reddening up, right?
• 32:12
  Speaker 2: Like you get an injury and it turns red. It's inflamed.
• 32:16
  Speaker 2: There is an increasing recognition that inflammatory molecules, things like
• 32:21
  Speaker 2: C-reactive protein, are different levels in different people. and that
• 32:26
  Speaker 2: those levels might be dictated by some underlying pathology, chronic inflammation,
• 32:31
  Speaker 2: and that chronic inflammation isn't good for you. And so
• 32:34
  Speaker 2: a lot of times they're using these blood proxies of inflammation,
• 32:37
  Speaker 2: often CRP. And let me give you an argument that
• 32:41
  Speaker 2: you'll see from the influencers about linoleic acid, which is
• 32:44
  Speaker 2: that linoleic acid is a precursor to arachidonic acid, which
• 32:49
  Speaker 2: is another fatty acid. This is another thing your body needs.
• 32:54
  Speaker 2: It transforms linoleic acid and essential fatty acid into arachidonic acid.
• 32:58
  Speaker 2: And downstream of arachidonic acid are a bunch of inflammatory molecules.
• 33:03
  Speaker 2: In fact, inhibiting arachidonic acid is some of the stuff
• 33:06
  Speaker 2: that like NSAIDs do, things downstream of arachidonic acid is
• 33:10
  Speaker 2: some of the stuff that NSAIDs do to reduce inflammation.
• 33:13
  Speaker 2: So it's like, well, it's on the pathway that generates
• 33:16
  Speaker 2: inflammatory molecules. Therefore, it must itself be inflammatory.
• 33:21
  Speaker 4: True?
• 33:21
  Speaker 2: False?
• 33:22
  Speaker 1: No.
• 33:22
  Speaker 3: Interesting and a plausible hypothesis, which needs to be tested
• 33:26
  Speaker 3: in randomized trials. This is a classic example of like,
• 33:30
  Speaker 3: here's an interesting mechanism. Could this be something that was true?
• 33:34
  Speaker 3: How would you know? Well, you would randomize people to
• 33:36
  Speaker 3: higher or lower levels and you would see what happens
• 33:40
  Speaker 3: to their C-reactive protein or some other measure, but that
• 33:44
  Speaker 3: would be the classic measure. And that would tell you
• 33:46
  Speaker 3: whether this downstream path is actually having implications for what
• 33:52
  Speaker 3: is realized in people. And they have done that. And
• 33:57
  Speaker 3: the answer is no, that actually higher intakes do not
• 34:01
  Speaker 3: correlate with higher metrics of inflammation or on many, many
• 34:06
  Speaker 3: different versions of inflammation measures.
• 34:09
  Speaker 1: Yeah.
• 34:10
  Speaker 2: A nice systematic review in the Journal of the Academy
• 34:13
  Speaker 2: of Nutrition and Dietetics in 2012 looked at 15 randomized trials,
• 34:19
  Speaker 2: which randomized people to higher linoleic acid intake versus other fats,
• 34:22
  Speaker 2: and not a single one showed an increased C-reactive protein
• 34:26
  Speaker 2: in the high linoleic acid group. There was also no
• 34:28
  Speaker 2: effect on IL-6, TNF-alpha, ICAM-1, LNP-selectin, fibrinogen, platelet activity, or
• 34:35
  Speaker 2: any of the measured prostaglandins or thromboxane. So if you
• 34:39
  Speaker 2: have a favorite inflammatory marker.
• 34:43
  Speaker 2: I know you're a big thrombocyanist.
• 34:44
  Speaker 3: And I'm, you know, I mean, I think in some
• 34:47
  Speaker 3: ways this is like great science. I think we should
• 34:49
  Speaker 3: like give some credit to this, which is like, this
• 34:51
  Speaker 3: is how science should work. People say, okay, here is
• 34:54
  Speaker 3: a thing that could be true mechanistically. Maybe we have
• 34:56
  Speaker 3: some evidence in mice. Maybe we just have some evidence
• 34:58
  Speaker 3: in vitro. You know, let's go test this in people
• 35:02
  Speaker 3: to see if it is important and it happens inside people.
• 35:04
  Speaker 3: You test it and then you learn something like that's,
• 35:07
  Speaker 3: like that's how science works. And that's really cool. But
• 35:10
  Speaker 3: once you get the answer in people, then you don't
• 35:12
  Speaker 3: go back to the other thing and say, oh, well,
• 35:14
  Speaker 3: because of this hypothesis I had. Well, no, you did
• 35:17
  Speaker 3: the hypothesis. You did the testing and then you said, no,
• 35:20
  Speaker 3: that's it. We're done with that.
• 35:21
  Speaker 2: Yeah, move on.
• 35:22
  Speaker 3: Yeah, move on. Let's move on to issue three.
• 35:25
  Speaker 2: Oh, I love issue three.
• 35:27
  Speaker 3: Issue three. Okay.
• 35:29
  Speaker 2: Can we play this? We're going to let someone else,
• 35:31
  Speaker 2: we're going to let a wellness influencer introduce issue three here.
• 35:34
  Speaker 4: I believe that the number one cause of obesity and
• 35:38
  Speaker 4: diabetes in humans... is excess linoleic acid in the diet.
• 35:43
  Speaker 4: Linoleic acid is an omega-6 polyunsaturated fatty acid found in
• 35:48
  Speaker 4: high amounts in seed oils. Excess amounts of this fatty
• 35:51
  Speaker 4: acid break down into compounds that make you want to
• 35:54
  Speaker 4: eat more, causing weight gain. Excess linoleic acid also causes
• 35:58
  Speaker 4: inflammation in the human body by raising oxidized LDL and
• 36:02
  Speaker 4: LP little a. Here's how much linoleic acid is in
• 36:05
  Speaker 4: these fat sources.
• 36:06
  Speaker 2: Tallo, low, 2%.
• 36:08
  Speaker 4: Ghee, 2%. Butter, 2%. Avocado oil, 14%. Olive oil, 15%.
• 36:15
  Speaker 4: Canola oil, 25%. Soybean oil, 55%. Corn oil, 60%. Animal
• 36:24
  Speaker 4: fats are clearly the best. If you want to lose
• 36:27
  Speaker 4: weight and be healthy, get the lowest amount of linoleic
• 36:30
  Speaker 4: acid in your diet as possible.
• 36:35
  Speaker 2: It's insane to say that the number one cause.
• 36:39
  Speaker 4: Number one.
• 36:40
  Speaker 3: Number one cause.
• 36:41
  Speaker 2: Number one of diabetes and obesity is excess linoleic acid. Like,
• 36:47
  Speaker 2: it's the most specific.
• 36:48
  Speaker 3: Are you familiar with snack foods, my friend?
• 36:54
  Speaker 2: The number one cause of diabetes and obesity in this
• 36:57
  Speaker 2: country is excess linoleic acid. Emily, let's take a break
• 37:00
  Speaker 2: and we will unpack that one.
• 37:03
  Speaker 3: Is it number one or number two after the break?
• 37:11
  Speaker 4: All right.
• 37:11
  Speaker 2: And we're back to talk about, you know, does linoleic
• 37:16
  Speaker 2: acid cause diabetes and obesity? And is it, in fact,
• 37:20
  Speaker 2: the number one cause of diabetes and obesity? Okay.
• 37:24
  Speaker 3: So this is a place where actually it will be really,
• 37:29
  Speaker 3: really quite important to talk think about relative to what,
• 37:35
  Speaker 3: and think about what the evidence says. Because in fact,
• 37:40
  Speaker 3: because there is a lot of linoleic acid in a
• 37:44
  Speaker 3: lot of processed foods, you can sometimes get, and we'll
• 37:47
  Speaker 3: sort of get into this, but you can get correlations
• 37:50
  Speaker 3: in these spaces.
• 37:51
  Speaker 2: Right.
• 37:52
  Speaker 3: And so we really want to like, actually, we want
• 37:55
  Speaker 3: to look at the evidence.
• 37:57
  Speaker 1: Yeah.
• 37:57
  Speaker 2: Your Twinkie has some linoleic acid in it. It may
• 38:01
  Speaker 2: not be the linoleic acid. It may just be the Twinkie.
• 38:03
  Speaker 2: It's the Twinkie.
• 38:04
  Speaker 3: The other things in the Twinkie.
• 38:06
  Speaker 4: Yeah.
• 38:06
  Speaker 3: So here, there is a little bit of potential mechanistic evidence.
• 38:13
  Speaker 3: There's like mouse study where more linoleic acid exposure raises
• 38:18
  Speaker 3: their food intake. So there's like a little bit of
• 38:21
  Speaker 3: mouse evidence, but the people evidence kind of goes the
• 38:26
  Speaker 3: other direction.
• 38:27
  Speaker 1: Yeah. Yeah.
• 38:28
  Speaker 4: The.
• 38:29
  Speaker 2: The mouse evidence suggests that there's an endocannabinoid effect of
• 38:33
  Speaker 2: linoleic acid. So you'll hear the cannaboid. That's the same
• 38:38
  Speaker 2: thing that marijuana does, like gives you the munchies. There's
• 38:42
  Speaker 2: some receptors in your brain that make you hungry. And so, yeah,
• 38:45
  Speaker 2: you can get a mouse to eat a little bit
• 38:47
  Speaker 2: more if you really restrict it to a linoleic acid diet. Although,
• 38:52
  Speaker 2: you know, I think.
• 38:55
  Speaker 2: Marijuana probably has more of an effect on diabetes and
• 38:58
  Speaker 2: obesity in this country than linoleic acid. Actually, the number one.
• 39:02
  Speaker 3: So most it's number two.
• 39:05
  Speaker 2: But you're right. I mean, the observational data clearly shows
• 39:11
  Speaker 2: that higher linoleic acid intake is associated with a lower
• 39:16
  Speaker 2: risk of diabetes and body weight because it's a plant-based oil.
• 39:22
  Speaker 2: Because you're eating more plants.
• 39:25
  Speaker 1: Right. Yes.
• 39:27
  Speaker 2: And I know you love Mendelian randomization studies. so I
• 39:30
  Speaker 2: did find a nice Mendelian randomization study in 2023, which
• 39:34
  Speaker 2: showed that higher genetically predisposed linoleic acid intake causally lowers
• 39:39
  Speaker 2: the risk of diabetes, fasting glucose, and hemoglobin A1c. My
• 39:43
  Speaker 2: faith in Mendelian randomization is shaken a little bit by
• 39:46
  Speaker 2: our earlier discussion of the LP little a studies. Nevertheless...
• 39:50
  Speaker 2: It's very hard to find any human data that suggests
• 39:53
  Speaker 2: that linoleic acid increases food intake or weight or risk
• 39:57
  Speaker 2: of diabetes and far from being the number one cause.
• 40:02
  Speaker 3: I mean, I think to believe this, forget about the
• 40:04
  Speaker 3: number one cause, to believe this even directionally, you have
• 40:08
  Speaker 3: to think that the biases and the observational data go
• 40:12
  Speaker 3: very strongly in the other direction, right? That somehow... the
• 40:17
  Speaker 3: people who are consuming a lot of linoleic acid are
• 40:20
  Speaker 3: really positively selected on other things. And that's like kind
• 40:24
  Speaker 3: of canceling out this effect in the observational data. And
• 40:28
  Speaker 3: it'd have to be quite large in the other direction.
• 40:32
  Speaker 3: So I think that's what you'd have to think, even
• 40:35
  Speaker 3: to have this move in that way, nevermind for it
• 40:38
  Speaker 3: to be important. And yeah, I mean, obviously that claim
• 40:41
  Speaker 3: is just like totally bananas and weird.
• 40:44
  Speaker 2: All right.
• 40:46
  Speaker 3: But you know what gets people to click on your thing?
• 40:48
  Speaker 3: If you're just like, linoleic acid is possibly the 437th
• 40:52
  Speaker 3: tiny contributor to America. That's boring. That's a boring reel.
• 40:57
  Speaker 2: I'm already bored. But guys, did you know that linoleic
• 41:00
  Speaker 2: acid is the number one cause of sperm count loss
• 41:05
  Speaker 2: in men? Can we just cut that clip?
• 41:09
  Speaker 3: And low testosterone.
• 41:10
  Speaker 2: We should do an experiment. We should just cut that
• 41:12
  Speaker 2: clip and put it on Instagram and compare it to
• 41:14
  Speaker 2: like nuanced discussion of, you know.
• 41:17
  Speaker 3: The kidneys.
• 41:17
  Speaker 2: The kidneys. So here's what Barry has to say about
• 41:21
  Speaker 2: the kidneys. All right. Let's move on to sort of
• 41:25
  Speaker 2: the fourth big claim you'll hear about seed oils, which
• 41:27
  Speaker 2: has to do with the omega-6 to omega-3 fatty acid ratio.
• 41:34
  Speaker 2: So the background here is... I think where this comes
• 41:38
  Speaker 2: about is that historically, like paleo diet world in the
• 41:43
  Speaker 2: olden days... There is some data that we ate a
• 41:48
  Speaker 2: fairly balanced ratio of omega-6 fatty acids versus omega-3 fatty acids.
• 41:55
  Speaker 2: This is debatable because it's based on dietary reconstructions, not
• 41:59
  Speaker 2: actual measurements, et cetera, et cetera. But we probably now,
• 42:02
  Speaker 2: nowadays in our modern diet, do have a higher ratio
• 42:05
  Speaker 2: of omega-6 to omega-3. And what the influencers will kind
• 42:08
  Speaker 2: of spin this as is like omega-6 is the like
• 42:12
  Speaker 2: it's the angry one that's going to make you inflamed
• 42:14
  Speaker 2: and bad and everything in, that omega-3 is the calm
• 42:18
  Speaker 2: yang to the raging yin of omega-6 or something like.
• 42:22
  Speaker 1: That, right?
• 42:23
  Speaker 2: And we're all out of whack. The study that gets
• 42:27
  Speaker 2: cited every single time they talk about this ratio is
• 42:33
  Speaker 2: a UK biobank study from eLife in 2024. 85,000 people.
• 42:39
  Speaker 2: And they actually measured the plasma levels of omega-6 and
• 42:43
  Speaker 2: omega-3 fatty acids in people. That's a nice design. So
• 42:45
  Speaker 2: it wasn't like dietary recall. They actually measured it, which
• 42:48
  Speaker 2: is great. And of course, measurement is because these are
• 42:51
  Speaker 2: essential fatty acids, you can't make them yourself. So measurement
• 42:53
  Speaker 2: actually does reflect kind of like what you're taking in.
• 42:56
  Speaker 2: So I actually really like that design. They looked at
• 42:59
  Speaker 2: the ratio of omega-6 to omega-3 and in the highest
• 43:02
  Speaker 2: versus the lowest quintile, so the highest fifth of people
• 43:06
  Speaker 2: in the ratio versus the lowest fifth, the highest fifth
• 43:08
  Speaker 2: had 26% higher all-cause mortality and 31% higher cardiovascular disease mortality.
• 43:15
  Speaker 2: So that's what you hear. You're like, oh, this ratio
• 43:18
  Speaker 2: is terrible. And the seed oils are giving us all
• 43:22
  Speaker 2: this omega-6. And then people actually read the study. And Emily,
• 43:26
  Speaker 2: if you read the study, instead of just talking about
• 43:29
  Speaker 2: the abstract, what do you learn about how horrible omega-6 is?
• 43:35
  Speaker 3: What you learn is that both of these fatty acids
• 43:38
  Speaker 3: are inversely associated with all-cause mortality, cancer, and cardiovascular disease mortality.
• 43:44
  Speaker 3: It is just that omega-3s are more strongly associated than omega-6s.
• 43:50
  Speaker 3: So both are better than other fat forms- saturated fat
• 43:54
  Speaker 3: in particular in this study.
• 43:56
  Speaker 2: Yeah. So to just say it again, the people who
• 44:00
  Speaker 2: had the highest level of omega-6 in their blood did
• 44:03
  Speaker 2: better than the people with the lowest level. The people
• 44:06
  Speaker 2: with the highest level of omega-3 in their blood did
• 44:08
  Speaker 2: better than people with the lowest level. It's only when
• 44:10
  Speaker 2: you divide the omega-6 by the omega-3 that you get
• 44:14
  Speaker 2: this sort of weird relationship.
• 44:16
  Speaker 3: But this all makes an unbelievable amount of sense if
• 44:20
  Speaker 3: your view is that this is all measuring something else.
• 44:25
  Speaker 3: So when I look at this data, what I see
• 44:27
  Speaker 3: is that these fat metrics, saturated fat, omega-6, omega-3, are
• 44:36
  Speaker 3: all measuring like diet quality. And the people who are
• 44:40
  Speaker 3: consuming a lot of saturated fats off on average, a
• 44:43
  Speaker 3: sort of worse diet quality. You see this everywhere in
• 44:47
  Speaker 3: any food frequency diet thing. Anything you see, you see
• 44:50
  Speaker 3: people are consuming a lot more fat, typically also a
• 44:53
  Speaker 3: lot more sugar, generally a lot more calories. That tends
• 44:55
  Speaker 3: to be a group with higher rates of obesity, less exercise,
• 44:58
  Speaker 3: et cetera, et cetera. The people were eating more omega-3s
• 45:01
  Speaker 3: kind of somewhere in the middle. This comes in a
• 45:03
  Speaker 3: lot of snack foods. And so they're going to have
• 45:06
  Speaker 3: a kind of intermediate diet. The people who are eating
• 45:07
  Speaker 3: a lot of omega-3s have the healthiest diet. And so
• 45:11
  Speaker 3: what we're measuring here is some sort of overall healthiness
• 45:14
  Speaker 3: of your diet and probably also many other things about
• 45:16
  Speaker 3: your behavior and resources and income and education level and
• 45:20
  Speaker 3: so on. And so that's what you're picking up in
• 45:23
  Speaker 3: the data more so, I think, than you're picking up
• 45:25
  Speaker 3: any of these things. But as you said, even if
• 45:28
  Speaker 3: you wanted to take this and say, like, these are
• 45:31
  Speaker 3: all causal, the people who have more omega-6s do better
• 45:36
  Speaker 3: than people with less. That's the kind of basic fact.
• 45:39
  Speaker 1: Right.
• 45:40
  Speaker 2: And if you really are worried about this ratio, if
• 45:42
  Speaker 2: you do think it's causal, then the solution would not
• 45:44
  Speaker 2: be to reduce your omega-6. It would be to increase
• 45:46
  Speaker 2: your omega-3, right?
• 45:48
  Speaker 1: Sure.
• 45:48
  Speaker 2: So eat your salmon, folks. This is the fatty fish
• 45:52
  Speaker 2: answer to all of this.
• 45:53
  Speaker 3: Yeah, you know who eats salmon? Rich people. Okay.
• 45:57
  Speaker 2: Just to not put too.
• 45:58
  Speaker 3: Fine a point on it.
• 46:01
  Speaker 2: I think there's one... real concern though, when it comes
• 46:05
  Speaker 2: to polyunsaturated fatty acids in general, and because seed oils
• 46:09
  Speaker 2: are high in PUFAs, I think we do need to
• 46:11
  Speaker 2: talk about what can happen when you fry with these oils.
• 46:15
  Speaker 2: Don't you think? Yeah.
• 46:18
  Speaker 3: I think we do have to talk about frying. Okay.
• 46:21
  Speaker 2: So I'll do the chemistry here. And that is that
• 46:25
  Speaker 2: when you Remember, there are these double bonds in polyunsaturated
• 46:29
  Speaker 2: fatty acids. And when you heat them up really hot,
• 46:32
  Speaker 2: and we're not talking like sauteing in your pan, we're
• 46:34
  Speaker 2: talking 175 to 190 degrees Celsius, like deep fat frying,
• 46:40
  Speaker 2: those double bonds can break. And when they reform, they
• 46:44
  Speaker 2: may reform in the cis position, the nice sort of
• 46:48
  Speaker 2: straight position like a saturated fat would have, or they
• 46:51
  Speaker 2: might reform in the trans position, and then it's a
• 46:54
  Speaker 2: trans fat.
• 46:55
  Speaker 4: So.
• 46:56
  Speaker 2: it is possible to convert a polyunsaturated fatty acid to
• 47:00
  Speaker 2: a trans fat, not just if you're Procter & Gamble,
• 47:03
  Speaker 2: but if you leave it on the stove for hours
• 47:06
  Speaker 2: and hours and hours. And we know that trans fats
• 47:10
  Speaker 2: causally increase cardiovascular disease risk.
• 47:15
  Speaker 4: Yes.
• 47:16
  Speaker 3: So I think that that is true. And then I
• 47:19
  Speaker 3: think it's really important to help people back down from
• 47:25
  Speaker 3: how should you think about that in the world? So
• 47:28
  Speaker 3: this is most important in the commercial fryer space. So
• 47:34
  Speaker 3: if you are commercially frying things at a restaurant, they
• 47:38
  Speaker 3: tend to hold the oil at some temperature for like
• 47:41
  Speaker 3: a long time, many hours, could be days. They're topping
• 47:44
  Speaker 3: it up continuously and it's like degrading. That is treating
• 47:48
  Speaker 3: these oils in a way that can lead them to
• 47:50
  Speaker 3: have some trans fats.
• 47:52
  Speaker 4: Mm-hmm.
• 47:52
  Speaker 3: When you are doing this at home, on the kind
• 47:55
  Speaker 3: of scale that most people are frying, even for deep frying,
• 47:59
  Speaker 3: even if you're like raising it to 375 and making
• 48:01
  Speaker 3: some delicious double cooked French fries in your fryer, that
• 48:06
  Speaker 3: is still really not enough time for this to be
• 48:09
  Speaker 3: a meaningful thing. And certainly like sauteing anything in some
• 48:13
  Speaker 3: canola oil, that's just like unrelated to this. It's not
• 48:16
  Speaker 3: getting hot enough for this to matter.
• 48:19
  Speaker 2: Yeah, exactly. It really comes from reusing and reheating these
• 48:25
  Speaker 2: oils at high temperatures. And there's data here, rats fed
• 48:28
  Speaker 2: sequentially reheated oil. So they took some polyunsaturated fatty acid
• 48:33
  Speaker 2: oil and they heated it like once and fed rats
• 48:36
  Speaker 2: and then they heated it twice and fed rats. So
• 48:38
  Speaker 2: the idea being it's getting successively more degraded by frying.
• 48:42
  Speaker 2: They did show a dose response effect in terms of
• 48:45
  Speaker 2: vascular inflammation. So you know, this is true. I mean,
• 48:49
  Speaker 2: we also know observationally that humans who eat more fried
• 48:54
  Speaker 2: food have a higher risk of cardiovascular disease. Like, can
• 48:57
  Speaker 2: I really blame the deep fat fryer versus just the
• 49:01
  Speaker 2: fact that you're eating a lot of, you know, fried chicken?
• 49:05
  Speaker 2: That's a harder one to untangle.
• 49:07
  Speaker 3: I mean, I think that these, probably the accurate thing
• 49:10
  Speaker 3: to say about this is that this is like mechanistically
• 49:12
  Speaker 3: plausible and we have other evidence to suggest that it
• 49:15
  Speaker 3: there could be some small impacts, but relative to other
• 49:19
  Speaker 3: things you are doing, these impacts are likely very, very small.
• 49:23
  Speaker 1: Yeah.
• 49:24
  Speaker 2: The more unsaturated your fat is, the more problematic this is.
• 49:28
  Speaker 2: And so a monounsaturated fatty acid like oleic acid doesn't
• 49:34
  Speaker 2: have as much of this issue. But of course, olive
• 49:36
  Speaker 2: oil is not good for deep frying. The smoke point
• 49:39
  Speaker 2: is too low But there is high oleic acid sunflower
• 49:42
  Speaker 2: and safflower oils. Those are technically seed oils. But if
• 49:45
  Speaker 2: you're going to be deep frying at home and you
• 49:47
  Speaker 2: are worried about this, those high oleic acid oils that
• 49:50
  Speaker 2: have a high smoke point actually work pretty nicely and
• 49:53
  Speaker 2: put a lot of that to bed. And of course,
• 49:55
  Speaker 2: you could also fry in saturated fat. You could fry
• 49:59
  Speaker 2: in beef tallow. And because it's saturated, it doesn't run
• 50:03
  Speaker 2: that risk of forming trans fats with extended heating.
• 50:07
  Speaker 1: Right.
• 50:08
  Speaker 2: Right.
• 50:08
  Speaker 3: OK, so at the top, I said I think the
• 50:10
  Speaker 3: right frame for this episode is to ask what you
• 50:13
  Speaker 3: could compare this to. And so I think it's reasonable
• 50:16
  Speaker 3: to ask the question about like substitution here. So let's
• 50:19
  Speaker 3: say you decided, you know, despite having listened so carefully
• 50:23
  Speaker 3: to our episode that you are a seed oil hater
• 50:26
  Speaker 3: and you don't want to consume any seed oils like that.
• 50:30
  Speaker 3: What could you do about that? What would you substitute to?
• 50:34
  Speaker 3: And so it's worth asking, what does the data say
• 50:38
  Speaker 3: about the different substitutions? There are kind of four things
• 50:41
  Speaker 3: people would swap in here. Beef tallow, butter, olive oil,
• 50:46
  Speaker 3: and avocado oil. So can we talk about those?
• 50:49
  Speaker 2: Yeah, it's going to make me hungry. But let's run
• 50:52
  Speaker 2: through them quickly. So beef tallow, because it's definitely like
• 50:57
  Speaker 2: having a moment. The Google Trends for beef tallow is
• 50:59
  Speaker 2: going up. like crazy. I actually think in fact, Whole
• 51:03
  Speaker 2: Foods identified tallow foods as their number one food trend
• 51:09
  Speaker 2: of 2026. So beef tallow is having a moment. What
• 51:12
  Speaker 2: is beef tallow? So it's fat. It's congealed beef fat.
• 51:15
  Speaker 2: It's about 50% saturated fat, 42% monounsaturated fatty acids, and
• 51:21
  Speaker 2: just 4% PUFA. In fact, the most abundant fatty acid
• 51:25
  Speaker 2: in beef tallow is oleic acid, the same as olive oil,
• 51:28
  Speaker 2: but it's also 26% palmitic acid, which we do know
• 51:31
  Speaker 2: causally increases LDL. So like That lipid hypothesis way back
• 51:36
  Speaker 2: in the 50s to 70s that saturated fat increases cholesterol,
• 51:39
  Speaker 2: which causes cardiovascular disease, true. That being said, we do
• 51:44
  Speaker 2: have ways to reduce your LDL now pharmacologically that we
• 51:47
  Speaker 2: didn't have in the 50s to 70s. This is my
• 51:50
  Speaker 2: dad's philosophy. He's like, I can eat all the red
• 51:53
  Speaker 2: meat I want because I can take my Lipitor and
• 51:56
  Speaker 2: keep my LDL down. And I don't know. Maybe there's
• 51:59
  Speaker 2: some truth in that. We know from several studies, from
• 52:03
  Speaker 2: substitution studies, that substituting beef tallow for other seed oils
• 52:08
  Speaker 2: increases LDL, but there's no outcome trials. So I can
• 52:13
  Speaker 2: tell your LDL will be a little higher if you
• 52:14
  Speaker 2: swap in beef tallow, but I can't know for sure
• 52:17
  Speaker 2: whether you're going to have more heart attacks.
• 52:19
  Speaker 3: Butter, similarly, very high in saturated fat, even higher than
• 52:24
  Speaker 3: beef tallow. It is delicious, but it does also raise...
• 52:29
  Speaker 3: your cholesterol for the same reasons. Yeah.
• 52:31
  Speaker 2: I was surprised looking at the constituents, like beef tallow
• 52:34
  Speaker 2: seems maybe a little healthier than butter.
• 52:37
  Speaker 3: Stop it. That's enough out of you. But yes, perhaps.
• 52:42
  Speaker 3: But butter is, it's so delicious. And I think that's worth,
• 52:45
  Speaker 3: I think that's worth saying. It is delicious and all
• 52:47
  Speaker 3: foods can be a sometimes food and butter is delicious.
• 52:51
  Speaker 2: All right.
• 52:51
  Speaker 3: So olive oil, I will say, is predominantly oleic acid,
• 52:56
  Speaker 3: which is omega-9 actually. not omega-3, right? It has omega-3.
• 53:00
  Speaker 2: Yeah, omega-3, you need fish stuff.
• 53:03
  Speaker 1: Yeah.
• 53:04
  Speaker 3: And this is a place where there is a real RCT.
• 53:08
  Speaker 3: So probably the most famous, well-known RCT in the dietary
• 53:11
  Speaker 3: world is the PREDIMED study, which is an RCT of
• 53:17
  Speaker 3: Spanish people, which looked at the Mediterranean diet. And there
• 53:20
  Speaker 3: is a substantial olive oil component They had some people
• 53:25
  Speaker 3: on a low-fat diet, some people on a Mediterranean diet,
• 53:27
  Speaker 3: olive oil, some people on a Mediterranean diet with nuts.
• 53:31
  Speaker 3: And both of those two latter groups, the Mediterranean diet groups,
• 53:35
  Speaker 3: including the olive oil group, had a much lower risk
• 53:38
  Speaker 3: of major cardiac events. And so it's reasonable to say
• 53:43
  Speaker 3: olive oil has been shown to be part of probably
• 53:47
  Speaker 3: the best evidence, the most evidence-based diet we have for
• 53:50
  Speaker 3: people at high risk of cardiovascular disease. That's about what
• 53:55
  Speaker 3: we could say.
• 53:56
  Speaker 1: Yeah, yeah.
• 53:57
  Speaker 2: It's great. You can use olive oil. Don't fry with it.
• 54:00
  Speaker 2: It'll smoke too much.
• 54:00
  Speaker 3: You can't fry in it. It doesn't get hot enough.
• 54:02
  Speaker 2: Yeah. Which brings us to avocado oil. That's a 70%
• 54:06
  Speaker 2: oleic acid oil with a pretty high smoke point and
• 54:09
  Speaker 2: a neutral flavor. So certainly feels like one that would
• 54:13
  Speaker 2: be better for frying with or for cooking at higher temperatures. Unfortunately,
• 54:19
  Speaker 2: for those of us spending a lot of money on
• 54:21
  Speaker 2: avocado oil... there is just a ton of adulteration of
• 54:27
  Speaker 2: avocado oil on the store shelves. So there's a big
• 54:30
  Speaker 2: study done by UC Davis that looked at products saying
• 54:35
  Speaker 2: made with avocado oil or even just avocado oil itself.
• 54:39
  Speaker 2: And 93% of the avocado oil containing products contained other oils,
• 54:45
  Speaker 2: sometimes unreported oils. Even the avocado oil in the jar
• 54:51
  Speaker 2: is just like, this is Pure avocado oil was widely
• 54:54
  Speaker 2: adulterated with canola, sunflower, and safflower oil, which are seed oils.
• 55:01
  Speaker 2: In a lot of cases, you're paying a premium and
• 55:04
  Speaker 2: still just getting seed oils. Interestingly, the same group looked
• 55:09
  Speaker 2: at the olive oils and found very little adulteration. From
• 55:13
  Speaker 2: what I understand, I guess there's more standardization in the
• 55:16
  Speaker 2: industry about olive oil like There's a lot of groups
• 55:18
  Speaker 2: kind of monitoring and making sure that extra virgin is
• 55:21
  Speaker 2: extra virgin, and avocado oil just isn't there yet.
• 55:23
  Speaker 3: Also, avocados are expensive, like capitalism. Of course you're going
• 55:29
  Speaker 3: to adulterate your oil. Avocados are a lot more expensive
• 55:31
  Speaker 3: than olives, and so the incentive to cheat is so
• 55:34
  Speaker 3: much greater.
• 55:34
  Speaker 2: The incentive to cheat is very high, which is why
• 55:37
  Speaker 2: there needs to be some regulators. But buyer beware when
• 55:41
  Speaker 2: it comes to avocado oil. It's good in theory, but
• 55:44
  Speaker 2: in practice, you might just be getting seed oil secretly.
• 55:48
  Speaker 3: All right, so last thing that we should talk about
• 55:49
  Speaker 3: is actual substitution trials. So we sort of have like
• 55:52
  Speaker 3: kind of talked around these, but there are a few
• 55:56
  Speaker 3: trials where they tried replacing animal fat with some kind
• 56:03
  Speaker 3: of typically seed oils. And, you know, I would say
• 56:07
  Speaker 3: on the whole, these trials, like there are some very
• 56:11
  Speaker 3: early trials of this. So there's like a 1969 trial
• 56:13
  Speaker 3: of like 850 men where they replaced, for some of them,
• 56:20
  Speaker 3: some of their animal fat with seed oils. And this
• 56:24
  Speaker 3: caused quite a large decline in their cholesterol that sustained.
• 56:29
  Speaker 3: And ultimately, they had lower rates of myocardial infraction, heart attacks,
• 56:35
  Speaker 3: and so on. So that definitely is a positive in
• 56:38
  Speaker 3: the direction of seed oils. Yep.
• 56:40
  Speaker 1: Yep.
• 56:41
  Speaker 2: Very famous study.
• 56:42
  Speaker 3: There are other studies which sort of show the opposite.
• 56:47
  Speaker 2: There is. I mean, the one that you hear a
• 56:48
  Speaker 2: lot about is the Sydney Diet Heart Study, which is,
• 56:53
  Speaker 2: for this type of study, a little bit on the
• 56:55
  Speaker 2: small side. This was published in the BMJ in 2013.
• 56:58
  Speaker 2: 458 men only from Sydney who were randomized to a
• 57:04
  Speaker 2: diet that was high in safflower oil and safflower oil
• 57:09
  Speaker 2: margarine to replace animal fats. This study, the control group
• 57:15
  Speaker 2: here was no specific dietary instruction and no study foods.
• 57:20
  Speaker 2: So a little bit of an uncontrolled control group. And
• 57:25
  Speaker 2: they actually found a higher overall mortality, although barely statistically significant,
• 57:29
  Speaker 2: in the group that got randomized to the addition of
• 57:32
  Speaker 2: safflower oil and safflower oil margarine. Yeah, small study, not
• 57:38
  Speaker 2: a great control group, just men in Sydney. The way
• 57:42
  Speaker 2: that I parse a lot of this data, when you
• 57:44
  Speaker 2: kind of see things going in one direction, you see
• 57:46
  Speaker 2: things going in the other direction, is to say probably
• 57:50
  Speaker 2: it doesn't matter that much overall. So there's just noise
• 57:55
  Speaker 2: in the system. And I don't think you're necessarily going
• 57:58
  Speaker 2: to save your life by only adding margarine to your
• 58:00
  Speaker 2: diet or only adding avocado oil to your diet. You
• 58:04
  Speaker 2: probably have to do larger scale lifestyle shifts to really
• 58:08
  Speaker 2: meaningfully impact outcomes. And the substitution of a single fat
• 58:12
  Speaker 2: is not going to do too much.
• 58:13
  Speaker 1: Yeah.
• 58:14
  Speaker 3: I think another way to say that is if you
• 58:16
  Speaker 3: look overall at people's diet, higher consumptions of some foods
• 58:20
  Speaker 3: are associated with more fried food, more ultra processed food,
• 58:24
  Speaker 3: more dietary patterns overall that we know to be associated
• 58:29
  Speaker 3: with higher rates of different kinds of health events, but
• 58:34
  Speaker 3: it's extremely difficult slash impossible to isolate some particular acid
• 58:40
  Speaker 3: or some particular, uh, oil and say, you know, this is,
• 58:43
  Speaker 3: this is the thing. Like if only you pull this
• 58:45
  Speaker 3: out of your diet, you would be cured. It's just,
• 58:49
  Speaker 3: it's just not how it works.
• 58:50
  Speaker 2: It's never one thing guys.
• 58:51
  Speaker 3: It's never one thing guys. Also, if you didn't have
• 58:53
  Speaker 3: any of this, as we noted before you'd be dead.
• 58:55
  Speaker 3: So note, right.
• 58:58
  Speaker 4: Note.
• 59:01
  Speaker 3: All right, Perry, are you a smash or pass on
• 59:05
  Speaker 3: seed oils?
• 59:07
  Speaker 2: I'm a smash. I think broadly speaking, probably. fats are
• 59:12
  Speaker 2: probably better for you than animal-based fats and seed oils
• 59:15
  Speaker 2: are a member of that panoply. So I'm okay with it. Emily,
• 59:20
  Speaker 2: smash or pass?
• 59:21
  Speaker 3: Likewise, I am a smash. I like a good seed
• 59:24
  Speaker 3: oil and also I like balance. So I'm happy to
• 59:27
  Speaker 3: have seed oils and animal oils and all kinds of
• 59:30
  Speaker 3: different fats and you should choose. I will say I've
• 59:35
  Speaker 3: written about this before and a friend of mine, Craig,
• 59:40
  Speaker 3: wrote to me to explain that the most important thing
• 59:44
  Speaker 3: is to match your oil to the cooking thing you're doing.
• 59:48
  Speaker 3: He said, I have beef tallow, I have duck fat
• 59:51
  Speaker 3: Then he listed a few other more obscure fats. And
• 59:54
  Speaker 3: some of them were good for some things and some
• 59:56
  Speaker 3: of them were good for others. And I thought that
• 59:58
  Speaker 3: was exactly the way to look at it. Sometimes you
• 1:00:00
  Speaker 3: need a seed oil. Sometimes you need butter. Sometimes apparently
• 1:00:04
  Speaker 3: you need duck fat if you're my friend, Craig. Thanks, Craig.
• 1:00:08
  Speaker 2: That's it for seed oils. Your mailbag question of the
• 1:00:10
  Speaker 2: week after the break. And we are back with our
• 1:00:18
  Speaker 2: question of the week. If you have a question for
• 1:00:20
  Speaker 2: Emily or I, leave it for us at wellnessactually.fm. We'd
• 1:00:25
  Speaker 2: love to hear from you and answer your question on
• 1:00:28
  Speaker 2: the air.
• 1:00:29
  Speaker 3: Let's play it.
• 1:00:30
  Speaker 5: Hey, Emily and Perry.
• 1:00:33
  Speaker 2: My kids are back in school. It's too late for me,
• 1:00:35
  Speaker 2: but for everyone else, how do you not get sick? Thanks.
• 1:00:41
  Speaker 2: All right. So Emily, what are your wellness hacks to
• 1:00:44
  Speaker 2: prevent getting sick once all the kids are back in school?
• 1:00:47
  Speaker 3: So my best wellness hack is that my kids are old.
• 1:00:50
  Speaker 3: So that's been like just totally crucial for me because
• 1:00:55
  Speaker 3: older kids get sick less than younger kids because I
• 1:00:57
  Speaker 3: think there's less licking of faces. I mean, maybe that's
• 1:01:00
  Speaker 3: not true. I don't know what it is anyway. It's
• 1:01:03
  Speaker 3: been good. But I don't think it's really a great
• 1:01:05
  Speaker 3: answer to this except for wash your hands. You should
• 1:01:07
  Speaker 3: wash your hands because you touch your face far more
• 1:01:10
  Speaker 3: than you think. But a lot of what people tell you,
• 1:01:13
  Speaker 3: like take this immunity booster, that stuff's just a bunch
• 1:01:16
  Speaker 3: of crap. I don't know. Do you take a bunch
• 1:01:17
  Speaker 3: of crap immunity boosters, Harry, like an idiot?
• 1:01:20
  Speaker 1: Nope. Nope.
• 1:01:20
  Speaker 4: I don't.
• 1:01:21
  Speaker 3: Nope.
• 1:01:22
  Speaker 2: There's no preventative value for like megadosing vitamin C or
• 1:01:26
  Speaker 2: anything like that. And yeah, wash your hands. That is
• 1:01:29
  Speaker 2: the number one, two, and three thing to do. And
• 1:01:30
  Speaker 2: my kids know as soon as they walk in the door,
• 1:01:32
  Speaker 2: they're going to put their bag down and wash your hands.
• 1:01:36
  Speaker 2: I'm hopeful that they do it at school from time
• 1:01:37
  Speaker 2: to time too, but you know.
• 1:01:39
  Speaker 3: Hope springs The other thing is sleep. So sleep is
• 1:01:44
  Speaker 3: actually quite good for your immunity. I think the sort
• 1:01:47
  Speaker 3: of terrible combination for parents of toddlers is that your
• 1:01:51
  Speaker 3: children are going to a place designed to make them sick.
• 1:01:56
  Speaker 3: That's on purpose they're supposed to get sick, so they
• 1:01:58
  Speaker 3: develop immunity for later and so on. And also you're
• 1:02:02
  Speaker 3: not sleeping enough often. And so the combination of sleep
• 1:02:05
  Speaker 3: deprivation and constant exposure to pathogens is really problematic.
• 1:02:10
  Speaker 2: Sounds good. Get your sleep, wash your hands.
• 1:02:15
  Speaker 3: All right. That's it for us today. Stick with us
• 1:02:17
  Speaker 3: next week when we'll ask, what's the deal with artificial sweeteners?
• 1:02:27
  Speaker 3: Wellness Actually is produced in association with iHeart Media. Our
• 1:02:32
  Speaker 3: senior producer is Tamar Abishai. Our executive producer at iHeart
• 1:02:36
  Speaker 3: is Jennifer Bassett. Our theme music is by Eric Deutsch.
• 1:02:39
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• 1:02:57
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• 1:03:00
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• 1:03:04
  Speaker 3: We'll let the influencers have the last word.
• 1:03:06
  Speaker 1: I like olive oil and butter, coconut oil, and things
• 1:03:09
  Speaker 1: like avocados and some Brazil nuts and walnuts and stuff.
• 1:03:12
  Speaker 1: So for me, I don't think seed oils necessarily will
• 1:03:16
  Speaker 1: kill me, but guess why I know they won't kill me?
• 1:03:18
  Speaker 1: Because I don't eat them.