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Food As Medicine: The Science of the Olive Plant with Sarah Gray

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Food As Medicine: The Science of the Olive Plant with Sarah Gray

From herbalists to passionate foodies, the olive plant is widely regarded for both its delicious fare as well as its medicinal properties.

So, how does one identify a good quality olive oil from those of lesser quality? What are the differences between olive oil, olive tapenade and olive leaf and what do these differences mean? What is the current research into olive oil and olive leaf telling us? If you've ever pondered these questions, with the help of Sarah Gray we dive deep into the world of the olive plant and unravel the science that makes this plant a champion when it comes to being a 'food-as-medicine'. 

Covered in this episode

[00:19] Welcoming Sarah Gray
[00:30] Today's topic: the phytochemistry of the Olive Plant
[00:51] Not all Olive Oil is created equal: how to identify quality?
[05:21] Oleocanthal: antioxidant and anti-inflammatory benefits
[10:50] Nutrient profile: Olive Oil vs. Olive Leaf
[13:18] Oleuropein and heart health
[15:34] Research limitation: correct terminology 
[18:10] Identifying a good from a 'bad' oil
[20:15] Adulteration in the food industry 
[23:11] Olive oil derived squalene
[27:25] Anti-inflammatory evidence
[29:00] Evidence for therapeutic dosing
[32:58] Olive leaf and immunity
[37:05] Cooking considerations with olive oil
[41:20] Limitations of the health rating system
[44:07] The Olive Wellness Institute


Andrew: This is FX Medicine. I'm Andrew Whitfield-Cook. Joining us on the line today is Sarah Gray, who's a registered pharmacist and she's general manager of the Olive Wellness Institute

And she's got a keen interest in the phytochemistry of the olive plant. And indeed, that's what we'll be discussing today. Welcome, Sarah, how are you?

Sarah: I'm well, thanks, Andrew. How are you?

Andrew: I'm really good. Now, there's so much to cover with just this seemingly simple plant. I was blown away by previous podcasts I've done. 

So let's talk first, though, about olive oil quality, because this is a massive, massive issue.

Sarah: Yeah. Look, you're right, we’re only going to skim the surface today but there's so much to talk about. And olive oil quality is a huge thing to start with. So I'm glad that we've started with that question. Extra virgin olive oil is what we should be looking for. So quickly, I'll just do a quick snippet of the difference. 

Extra virgin olive oil is the fresh juice of the olive plant, really. So the olive fruit comes off the tree, it gets pressed into extra virgin olive oil. As you go down in grades, you get more refining. So with extra virgin olive oil, that's no refining, it's very natural. Olive oil is something that's been more refined.

So it's using a lower quality olive to start with, so when the oil gets pressed, it's high in fatty acids or things that are not palatable or can't be digested well. So it goes through a refining process where companies might add chemicals or heat or other things to refine it, and it actually strips it of the most important thing. 

The most important thing of extra virgin olive oil is the minor components. All these beautiful antioxidants that come from the olive naturally. When you refine it, not only do you lose all of those, you also produce trans fats. So you're really looking for that extra virgin.

Andrew: Yeah, it seems to me to be the reverse of things like wine-making and even herbal medicine extraction, where you want the mark to be left macerating for an extended period of time to get more and more of the actives. Here you want as fresh as possible.

Sarah: Hundred percent. And it kind of makes sense - and we'll talk about olive leaf later as well - but as soon as something is really fresh and you get it from the tree or the plant and quickly snap-lock that goodness in the product, you're going to get the beautiful benefits of what's in nature. 

So the more you do to that, the longer you let it sit when it becomes a fruit, more so than a herbal extract per se, it becomes a lesser quality product. So really, the first and best tip is to look on the label and make sure it's clearly labelled extra virgin olive oil. So anything that's got, “olive oil refined" or “blended” or "light olive oil” is not going to be the real deal.

Andrew: But even then, there was an issue, and I can say the company, Bertolli in the United States, was sued for $11 million U.S. I think it was, or $7 million U.S. because they said something on the label but that wasn't what was in the bottle. So how can we trust what's in the bottle?

Sarah: Yeah. And it really opens your eyes when you start getting into this topic. Because you think as a consumer, you buy something that's labelled that way as a food, you think you're getting it. As you become more and more involved in the food industry, you find out that a lot about that is not actually true. 

We're lucky in Australia that we actually have a voluntary code, so not every company will take part in it, but there are a lot of companies that do, so consumers have a huge choice. The Australian Olive Association have created a voluntary code, which is a certification, basically. It's a triangle. It's on the side of the bottle. A number of Australian brands are using that product, so I definitely would choose an Australian olive oil to get something that's fresh. 

And by getting that seal of certification, you know it's being tested for quality, for the right fatty acid profile, and the right composition of an extra virgin olive oil. So, yes, you're right, be very careful. Always check for that certification on side of the pack. Two other things you can check for...Yes?

Andrew: Well, it's another argument to buy Australian.

Sarah: A hundred percent. And think about it, it's fresh, it's a fruit, so you don't want it sitting in a plane or being imported from… I know we have this romance associated with Italian or Spanish olive oil. If you're in Italy or Spain, fantastic. That's what you should be consuming. 

Andrew: That’s right.

Sarah: But if you're in Australia, we've developed this amazing olive oil industry, which is kind of a bit weird because people don't think of Australia and olive oil. But we've developed a beautiful industry and we have some of the best quality extra virgin olive oils in the world. So consume local.

Andrew: Yeah. Absolutely. And do you know what's really evident to me since becoming interested, I mean, really interested in the quality of olive oil, and indeed it was yourself and a colleague of yours who changed my mind. So, thank you.

Sarah: Thank you.

Andrew: But more so than that, not just changing to olive oil Australian-made, but also changing my dietary habits to the choice of the olive oil from a lighter one to now I choose the heavier one. And what I'm picking up is that fruitiness.

Sarah: I love that. I love you've gone on that journey. I think we've been talking about it as you've gone on that journey. And I think you raised a really good point there. So when you're buying an extra virgin olive oil, it doesn't mean you can't have a light flavoured one or a medium flavoured one. 

So definitely don't buy a light olive oil, but brands will talk about the flavour profile, and what you're consuming there, Andrew, is the best. You're consuming the more robust, the peppery one, the one that's got some amazing compounds, like oleocanthal that we'll talk about a bit later. And that pepperiness, the more peppery, the more antioxidants, and you're getting the best benefits.

Andrew: Okay. Right. So, okay. So that's an interesting thing. The pepperiness. I know that you said to talk about it later, but, you know, can we talk about it now, what was the oleocanthal?

Sarah: We could talk about that now, for sure. It's one of my favourite, favourite topics in olive oil. So it's this really amazing biophenol that actually gets produced in the extra virgin olive oil production. 

So basically, what happens is you crush the whole fruit, including the pit. The pit kind of creates these crunchy edges that breaks all the oil sacs sitting inside the olive, and then enables the oil that's in those sacs to be enriched with what's in the pit, in the skin, and the fruit. And that's what gives all of the minor components or biophenols, polyphenols into the oil. 

In that amazing process, like a pit tapenade is produced. This unique biophenol, oleocanthal, is chemically produced through that process naturally, like, natural chemical processes. So you won't find oleocanthal with any other product in the whole world except extra virgin olive oil. So I think that's super cool. 

And being a geeky pharmacist, I love it because Gary Beauchamp in the U.S., together with Russell Keast who's a professor out of Deakin in Melbourne, they did a bit of work and it was a cool story, actually. They were doing work on ibuprofen. And when they had the ibuprofen, they realised that it caused a very bitter flavour or pungency at the back of their throat almost that made them cough. Gary Beauchamp happened to go to an olive oil tasting course and he had the extra virgin olive oil and had the same taste. And he said, "I'm convinced there's something connected here."

So, amazingly, did some research that was published in 2005, and it showed that extra virgin olive oil and the oleocanthal component actually works on the non-steroidal anti-inflammatory pathway and blocks COX-1 and COX-2 enzymes, reducing pro-inflammatory prostaglandin release. 

So it actually acts on the same pathways as this anti-inflammatory. It kind of makes you think that's probably why in Mediterranean populations with epidemiological research and studies show that lower risk of chronic low-grade inflammation and those types of associated diseases in that population. Perhaps there's some sort of link between that low-grade anti-inflammatory being in their diet for such a long time.

Andrew: Well, that's really interesting because the... what did they used to call it? The French paradox, that's right. The French paradox. And they put it down to red wine. But subsequent research has sort of pulled out, "Well, actually, maybe it's more vegetable intake and olive oil."

Sarah: Yeah. And those beautiful, fresh leafy greens and herbs and the vital herbs and tomatoes. And the combination, if you cook tomatoes in extra virgin olive oil, the lycopene is more easily absorbed by the body. 

Andrew: Yes, right.

Sarah: And it's the frito, a beautiful recipe that's a very common tomato sauce recipe. It's that combination. So by all means, although I love extra virgin olive oil, it's not eaten by itself. It's eaten in combination with that wonderful dietary pattern of the Mediterranean.

Andrew: I'm going to go off on my own little segue here.

Sarah: That's okay.

Andrew: When you're thinking about that cough at the back of the throat, is there any tie in any research that you might've stumbled upon that might be looking at an interaction with TRPV1 receptors at all? I know it's not...

Sarah: Nothing that I've seen. I haven't seen anything. There's not a lot of research… it's amazing that Gary Beauchamp did the research he did, but there hasn't been a lot more research in oleocanthal. 

I can certainly direct in the show notes or in the notes to this session, there is an author in the U.S. doing a whole chapter in a book on oleocanthal, Amal Kaddoumi. So Amal may have come across that. So I can certainly share that, but nothing that I've read in the literature I've been through, and I've read a fair bit.

Andrew: Well then, maybe we might have to get her onto FX Medicine.

Sarah: Yeah. She's amazing. And there's so many olive people I could recommend. We launched a podcast a year ago, and the guys at the podcast studio said, "How can you do an olive episode every month?" And we're now doing them twice-monthly because we've got so many topics to cover. So it's endless.

Andrew: Well, we'll have to direct our listeners to your podcast as well. We'll put that in the show notes.

Sarah: Yeah. Thank you. Thanks, Andrew.

Andrew: Now, the biophenols. Now, we've discussed one, what about the others? And certainly, the research of Ian Breakspear, as well.

Sarah: It's amazing. So much to talk about in that question. It seems like a quick question, but my mind goes crazy. 

So two things to point out here: Extra virgin olive oil has lots of antioxidants, but so does olive leaf extract. So you get a nice blend. Actually, you get a different biophenol profile in extra-virgin olive oil than you do in olive leaf extract. It kind of makes sense you getting more of the oil-soluble in oil versus more of this water-soluble in the olive leaf extract. And they beautifully complement each other. 

Extra virgin olive oil, the main antioxidant in there would be squalene. It's not a biophenol, it's a triterpene, but squalene is by far the most abundant. And that is followed by hydroxytyrosol and derivatives. So hydroxytyrosol is a wonderful antioxidant with a lot of different research. It's actually the only biophenol that I've read about that actually crosses the blood-brain barrier. So it can scavenge free radicals in the nervous system, a bit of in vitro data around that that I found. 

And then when you go through the biophenol profile, there's other ones. There are other minor components. So oleocanthal, there's ligands, apigenin, there's a whole range. And then when you flip to olive leaf extract, there's this wonderful antioxidant called oleuropein. It's actually not that rich in extra virgin olive oil. I think some of the work I've seen Ian do, Ian Breakspear, who some of us would know, shows that olive leaf extract has about 500 times the amount of oleuropein versus extra virgin olive oil. It just isn't prominent in olive oils. So if you want to get that one, you'd go for the leaf, and the leaf extract also is fairly prominent in hydroxytyrosol. 

Just one quick thing there before we move on, for those who aren't aware or haven't read about this, hydroxytyrosol is the end degradation byproduct of all of the biophenols. So they all become hydroxytyrosol. 

Andrew: Right.

Sarah: So they're all you're going to get there at the end, which is not a bad thing, but that's probably why we have more in the extra virgin olive oil. It's because they've gotten to that point a bit quicker versus the extraction method in the form of the olive leaf extract enhancing that in the biophenol profile.

Andrew: Got you. Okay. Is there a greater or different activity of oleuropein compared to hydroxytyrosol?

Sarah: Yeah. So oleuropein has its own distinct health benefits. It's been researched mainly for its anti-inflammatory effects in vitro, but what it really has been shown to do in most of the human clinical work is have a cardio-protective effect. That's why you see a lot of the olive leaf extracts calling out that heart health, cholesterol health component. 

So there's a number of clinical studies and we can share links to them as well showing that oleuropein levels of about 100 milligrams, and then hydroxytyrosol at about 5 milligrams and above, if you take that in a dose a day in an olive leaf extract, can actually have positive impacts on modestly reducing blood pressure and modest reductions in overall total cholesterol and LDL cholesterol, and even some protection around LDL oxidation. 

Now, I just want to be clear here, we're not talking super drastic reductions. We're not talking that you could replace other herbs, nutrients, or drugs with it, but as part of an overall lifestyle, it's got very positive impacts on the heart and cholesterol health.

Andrew: So millimetres mercury, what sort of reduction?

Sarah: Actually, I have that here. I thought you might ask. We have a cool section of the Olive Wellness Institute that goes through all the systematic literature reviews of each of the sections of the body. So in terms of blood pressure, we're looking at a 3.95 millimetres of mercury reduction in systolic blood pressure, and 3.3 in diastolic blood pressure. So it's not a lot. We're not talking a lot. I haven't got the figures here for extra virgin olive oil. They're actually more impressive, the studies on extra virgin olive oil.

Andrew: That was the one that I...

Sarah: Yeah. So I can definitely share you those numbers in the show notes. I can't remember them off the top of my head, but the SLR section on the front page of the institute goes through all of that and tells you exactly what the reduction was, so I'll send a link for you to share for that as well.

Andrew: Yeah. It was actually a program on television. There was a productivity program, Dr Michael Mosley. Now, I have a normal scepticism of the “N equals three” studies that TV shows do, and particularly because they're believed and it’s just like come on, you know? However, I found that it was really interesting that Michael Mosley went to, I think it was a Scottish researcher, who was...

Sarah: It was, yeah.

Andrew: Yeah. And they were talking about the intake of 30...I hope I got this dose right, 30 mls of olive oil per day. And one of the things they said on the TV show - which I dispute - is you can take any olive oil.

Sarah: Yeah. We spoke about this. I love this, actually, because it shows some of the work and will link into health star rating as well. Some of the work we're doing at the institute is to try and ensure that any research that's completed actually adequately categorises and has the right terminology around the oil use, which sometimes causes a bit of a discrepancy in the research. 

Now, before I was talking about how extra virgin is different to ordinary olive oil, and that olive oil has none of those minor components or biophenols and some trans fats. The thing olive oil and extra virgin both have, is this really healthy fat profile. They've both got monounsaturated fats. So no doubt, they're both going to impart that healthy monounsaturated fat effect in the diet.

However, when we look for the evidence associated with the Mediterranean diet, a bit about how I was talking about that dietary pattern, it's not just the fat profile. The main thing, in my belief, in looking through the evidence and lots of experts in this space is that the benefits of the diet are around those biophenols, those polyphenols, those minor components. 

So when you look at the research, it might be that it was just olive oil. Yes, there still is going to be a benefit of switching from a polyunsaturated canola or sunflower oil, to an olive oil monounsaturated fat. If you've got to switch, you might as well switch to an extra virgin and get all of those biophenols at the same time and get those benefits, the anti-inflammatory, there's so much more in there. And if only a portion of your diet is going to be fat, make it a really good one that gives you all these nutrients at the same time.

Andrew: Absolutely. And I've got to say, making that switch to the heavier flavour, I've had a reticence previously that the flavour would become overwhelming, but it's really interesting now that, I actually take a dose of olive oil. No bread, no dipping, just oil. And what I'm liking is, as you say, that flavour, that pepperiness. The funny thing that I think people have got to get used to is that it's an oil, not a drink. So it’s the texture, but once you do that, once you ...it's almost like an acceptance. Once you accept that, it's kind of like...

Sarah: It is. Yeah.

Andrew: It's really funny.

Sarah: And it's a good point you brought up there too. So there's a couple of ways you can tell whether you're having a good oil or not so good oil because even if it's labelled extra virgin, unfortunately, there's still some products that are on shelf...like, it blew my mind when I started in this industry. Some brands don't even have a best before date. And we're talking about a fat that's going to break down. So you want a fresh oil within about a year of its harvest date. So some brands list that. 

And the thing that I find really interesting is about mouthfeel. So when you're doing sensory tasting of extra virgin olive oil, if you taste it and it leaves a greasy mouthfeel and you feel very unwell after it and it smells a bit like car oil or it just doesn't smell good, it's probably rancid, and the fat's broken down. 

What you want is one that smells beautifully fresh, like fresh-cut grass, tomatoes, very fresh flavours. And then when you put it in your mouth, it should leave a very clean mouthfeel. So you might feel a bit… it's a fat, but you're going to feel a very nice mouthfeel where afterwards you haven't got that greasiness in the mouth.

Andrew: No, not at all.

Sarah: So try it with what you buy… yeah, just try it. And I heard someone say yesterday in one of our podcasts that we just recorded, if it leaves a horrible taste in your mouth, take it back to your supermarket or retailer and say, "This oil is off.” Don't accept that as a consumer. Just like with any other product, if it's not a good quality, we need to try and make sure we hold the industry to a high standard.

Andrew: You know, you raise an interesting question there, and that is the issue of adulteration. And as natural health practitioners, we all think that adulteration is an issue only within our industry. And indeed, adulteration is a far worse issue in the food industry than any herbal issue of swapping, whether it be accidental or...

Sarah: Hundred percent. Yeah. We worked with the, you know the American Botanical Council, the ABC?

Andrew: ABC, yeah.

Sarah: We actually through some partners...

Andrew: Mark Blumenthal.

Sarah: Yeah. I love him. We did some work with him, I'll share it with you, around adulteration of the olive oil market in the U.S., and we published that with them. So I might share that for your readers to have a look at because it's an eye-opener.

Andrew: That'll be an eye-opener.

Sarah: Even in supplements. So olive oil on the shelf, but olive oil is used as a lot of carriers in supplements, and in capsules, and in beauty products. And there's also adulteration in that respect where it's not olive oil or it's pomace oil, or it's rancid. And you don't want to put that on your skin or have that in a capsule either, as much as eating it.

Andrew: I was attentioned to this issue actually by - I'm going to do a call out here - Tass Allis. This man has given his whole life to our industry professions. And I remember him talking to me about the issue with tomatoes. And he said, it'll state one thing on the can, he said, "That's not in the can." So it's still a tomato, but it's a different species. And this is where the issues lie when you've got inexperienced and unqualified…

Sarah: Yes. But then I think that, to me...I love natural health and I just think, to me, that empowers us as practitioners. I know I'm a pharmacist, but I've also gone into that integrative space with nutrition. And I think that empowers us as practitioners. We can offer that to patients and to consumers and to the public. 

Not only can we give them information about supplements and nutrients and health and wellbeing, how they can select food products that are the right ones, how they can cut through that kind of noise, these podcasts help with that, the education helps with that. 

It means it gives you another place in society because you tell people around the dinner table and they just, they can't believe it. And they won't forget something like that. So when they choose those tomatoes in the can next time, they'll know exactly what they should be looking for. I'd actually like to know more about that too because I...

Andrew: You know, we all love the conversations about choosing a great meat or choosing a great avocado. But when it's in the can, when somebody else made that decision, it's almost like we bow to their knowledge.
Sarah: Yeah. I want to learn more about canned tomatoes now.

Andrew: Now, Sarah, you mentioned squalene before. Squalene.

Sarah: Yes. Yes. Yes.

Andrew: And this is something that I have never understood. Years and years and years and years ago, I remember capsules of squalene. And I remember that they were of particular interest to the overseas market, particularly Chinese and Taiwanese people. And they took it for heart health. 

But one of the things that I thought it was involved in was cholesterol reduction. And I don't understand this, because you look at the biochemical pathway, the pharmaceutical pathway on which statins work - HMG, coenzyme A, reductase inhibitors - squalene’s down there before cholesterol. So why would a statin inhibit that to make...? I don't get it. Can you help me? Help us.

Sarah: Yeah. And you know, I chatted to you about this last time and I was midway through a literature review, which I've now finished. So I'll share with you what I think on the topic. I'm not an expert, but I can tell you what my thoughts are from what I've read. 

I will come back to that first point around the squalene supplements. Yes, it's still amazingly popular, particularly in overseas markets. I just would mention one thing though: a lot of them are shark-based. Certain breeds of sharks in their liver have squalene, so I'd say 90%+ of the supplements on the market are shark liver squalene. So, not a very sustainable form. So if you are buying...

Andrew: I've got an ethical...

Sarah: Yeah. So if you are buying one, try and find an olive-based one if you can because it's going to give you a plant-based option. 

Now, I had a look through this market and I actually was like you, why are people talking about cholesterol health and heart health? And this is the best that I can come up with, and I've spoken to a couple of naturopaths about this as well. 

As you mentioned, we know squalene is one of the major intermediates in the biosynthesis of cholesterol. It's in that pathway. We know cholesterol is important in the body too, so we need cholesterol to do certain things. But the only reason why we can think that they’re putting "supports cholesterol health" or "supports heart health" [on the products] is because it's providing the body that squalene to produce cholesterol in that pathway. 

I've looked through, I think it was over 170 papers on this, and it's completely inconclusive and there's conflicting results. Some papers are showing that it increases total cholesterol, triglycerides, and LDL. Some shows modestly reduces it, but nothing I read overwhelmingly tells me that taking a squalene supplement is going to reduce your cholesterol. 

So myself and...you might know Bob Wootton. Bob's a naturopath that I've worked with for a number of years. We spoke about this. And the only thing we could think of is they were able to make those claims around that "supporting cholesterol health" message, not around reduction. I actually couldn't see any supplements with...not that you can make claims like that on supplements, but I couldn't see any around that. So I think the industry has done a really good job of making this halo around it. It's for cholesterol health, it's for heart health, and people have taken that on. It's a good antioxidant for other reasons, not for heart health, like it's...

Andrew: Well, that's where I was going. So maybe it's got to do with, you've got a component, but the component was originally from a source, and then they find that component from a different source. And we think it's got these connections. 

Sarah: Yes.

Andrew: If it was always from olive leaf, then you've got those other biophenols as you spoke about. So maybe it has to do with lipid protection rather than lipid manufacture.

Sarah: Yeah. Protection of LDL oxidation, perhaps, or, squalene also is very good… If you look at the evidence, it can be good for… it's got these brain health studies, or skin health. I mean, epidemiological research in the Mediterranean shows a lower incidence of skin cancer in those populations because the squalene is thought to migrate to the skin surface and have that antioxidant protective effect. So I think it's wonderful. I think if you look at the industry, it's pushing for heart, but it's got a lot of other stuff around it as well. So more to explore for us on the institute, I think, as well around squalene.

Andrew: The olive oil I'm taking is making me look as much as five years younger. I'm 100 but I look 95.

Sarah: Pour it on your face as well, and your hair.

Andrew: You mentioned oleocanthal before, and I'd really like to find out more about its anti-inflammatory effect because my initial thoughts on oleuropein, and this was work initially done by Upjohn decades ago. And it's all in vitro and in doses that were way above human doses. So I initially poo-pooed olive leaf extract. 

Then I started to rethink it and open up my mind a bit more, and learned that oleuropein has some anti-inflammatory effects. Maybe that's why it was useful in coughs and colds, in reducing that inflammation.

Sarah: Okay. Yeah. Most of the oleuropein anti-inflammatory effects I've seen have been more around that cardioprotective. I have seen some other data around inflammation pathways. I saw a couple of papers I looked at, so I'm just going to refer to them here showing that it reduced the production of interleukin. So including IL-6 and some of those other markers like iNOS and COX-2, all in vitro or animal-based having cardioprotective. It's the main thing I've seen around oleuropein. I'd thought of something else there around anti-inflammatory that will come back to me, I'm sure, if we keep talking. Yeah.

Andrew: Interleukin-6, I mean, you've got so many autoimmune disease issues. Irritable bowel?

Sarah: Yep.

Andrew: You've got so many conditions there where olive oil would play a role as part of a healthy diet. Do you talk about therapy? Well, in some instance perhaps, but I'd combine it with other things obviously.

Sarah: Hundred percent. And when you think about that, you're talking about therapy, it's about the amount that's included in the diet. So we're going on a journey in the institute now to move from “what is the science” to “what's the culinary applications?” And about 25 millilitres to 50 millilitres of a good quality extra-virgin olive oil is going to give you what you need to infer those heart health benefits, those other benefits, inflammation. 

Fifty grams of extra virgin olive oil with high antioxidants, so the oleocanthal, is equivalent to about a 10% dose of 1 ibuprofen tablet, so a 200-milligram ibuprofen tablet. 

Andrew: Right.

Sarah: That gives you that understanding of how powerful this can be as part of a daily inclusion in your diet. And then if you want the oleuropein cardioprotective effects, you could add the leaf in because remembering that's not as high as in the extra virgin. So some people say to me, "Oh, can I use either or?" Not really, because you're not going to cook with olive leaf. I say both of them give you the wonderful benefits of the antioxidants from the olive. It's wonderful.

Andrew: So, firstly, just a question you were saying about a tenth of 1 ibuprofen, so 200 milligrams. Normal dose of ibuprofen is two 200 milligrams.

Sarah: Yes, 400 milligrams.

Andrew: So you're talking about an overall...the same sort of action, but certainly not to the strength of that.

Sarah: No. It's not going to relieve a headache or anything. It's just low-grade inflammation.

Andrew: No, but there's also the issue of long-term 400-milligram dosing of ibuprofen and that's certainly gut inflammation. And in the end, there's also the issue of renal disease, particularly from taking other medications. We don't see that with olive oil.

Sarah: No. I lecture at Torrens for the drug and integrated pharmacology subject and I think it really shocks the students when you go through the side effect profile of a non-steroidal anti-inflammatory. That and opioids. They can really affect pretty much… I do a picture of the whole body from top to bottom and you could pretty much point one bit of every system where they're having some sort of effect. 

Now, you do need them sometimes under really close medical supervision, but because they're so easily available over the counter, people can just think they're lollies and they're definitely not. So you're right.

Andrew: Not just over the counter, in your supermarket. You know?

Sarah: Yeah, exactly.

Andrew: There was one issue I forgot to raise there and that's with all NSAIDs, all of them, have cardiovascular risks and they are stratified depending on the strength of the NSAID. That research has been done. So these are not safe pills. These are things that we need to treat with respect and, indeed, intrinsic…

Sarah: Short term. Short term acute for something that needs really rapid reduction in inflammation, but certainly not every time you've got a headache you take two. That wouldn't be my recommendation. 

But I always try and get people to go talk to your health professional, your naturopath, your pharmacist, your herbalist, your doctor. Don’t just pick things off the shelf. It's one of my biggest peeves that people self-select because it's so available. So encouraging them back into the system is really important.

Andrew: Yeah. So a very well-known pharmacist, Gerald Quigley, every year, Gerald walks into a supermarket and purposefully buys a lethal dose of paracetamol, i.e. multiple packets of paracetamol, to see if anybody will stop him and caution him. Nobody has.

Sarah: They don't. Yeah. That's another one. We could do another episode on that round on all of that stuff, but Gerald's a great advocate for this kind of integrative space as well.

Andrew: Can we discuss immunity, the olive leaf extract? 

Sarah: Certainly.

Andrew: That’s what it's touted for, that’s basically the indications.

Sarah: Yeah. And it's interesting, actually, because products talk about that. And a lot of it is based on traditional evidence, which I'm a huge fan of going through traditional evidence and having that respect for traditional uses of products. 

So even as far back as the 1800s, being used as an anti-infective for things like malaria and being used to try and prevent colds and flus or keep the immune system strong. So there's lots of stuff if you look back for traditional evidence, heaps on this. 

However, there's not a lot of scientific evidence which sometimes puts us in a bit of a pickle with those quite black and white practitioners who want that science there. I do feel strongly about the traditional evidence and feel that it has a strong role to play. But if we just talk about the science, a lot of in-vitro, a lot of animal work looking around its ability to act as an anti-microbial, which could contribute to its ability to break down viral membranes and reduce viral infectivity.

Back in the day, they gargled olive leaf tea a lot to reduce inflammation and infection in the throat. And then there's one paper published, I think it was year 2019 and it was a human study. It was high school athletes, so it was 32 of them. And they had to look at giving an olive leaf extract versus placebo. And they had to look at upper respiratory infections and it was found that although there was no decrease in the incidence, there was a 28% significant reduction in sick days in the ones taking OLE versus not. And also the duration was a lot shorter. Sorry. There was 9.7 days versus 12.3. Not a lot more in humans to go with, to be honest, unfortunately.

Andrew: Yeah. But that's a 25% reduction. So that's decent if you think about...

Sarah: I think it's a great paper. Yeah.

Andrew: Yeah. If you think about days off work and what that's going to cost the economy, that's significant.

Sarah: Hundred percent. Yeah. Yeah.

Andrew: I mean, I remember, what was it, one of the antivirals, when they were looking at...was it flu?

Sarah: Not the ones for the flu-like Tamiflu and all of those. Oseltamivir or something.

Andrew: Yeah, Tamiflu, yeah, yeah. I can't remember, but it wasn’t that dramatic.

Sarah: No, no, they're not really. And I think the reason why there's probably not more human research is funding can be hard in this space but there's certainly… I’ve got in-vitro papers showing it stimulates phagocytosis. It can help to reduce the viral adhesion, anti-fungal activity. So there's so much in that space.

Andrew: That's really interesting about the viral adhesion. I mean, in the current day, I'm not suggesting that this means or way of therapy for COVID-19. I'm not suggesting that. But talking about coronaviruses, i.e., the common cold, and the economic impact of days off work and things like that. If you just...let's just go common cold. If you think about that and you think about the use of olive leaf extract in maybe mitigating, as you say, the amount of days off work and the severity, I mean, my goodness.

Sarah: It plays a role. There's a bit of… I'd love to do some research specifically looking at its effect on coronaviruses. There isn’t a lot. There’s a very small amount of evidence on viruses and everything I'm referring to here is small in vitro studies, but it's promising, and it's nice to think that we got a human study published in 2019 and there's a couple on the clinical trials register in Spain. 

So in the next couple of years, I think we'll have a lot more around these in human research to pull that very scientific, not-so-open-to-integrated medicine community along on the journey because I think that'll start to make them feel a bit more confident in the product itself.

Andrew: Okay. So I know I've sort of gone into immunity with olive leaf, but I need to get back to olive oil a little bit.

Sarah: Yup. Of course.

Andrew: Cooking with olive oil. So there's been some initial issues raised about the smoking point and certainly about the use with non-stick frying pans. Indeed, I was cautioned when we… don't hassle me, we bought a nonstick frying pan, it's PPOE. But there was some advice there saying don't use olive oil, so we actually use coconut oil to prepare. But on my barbie, it's olive oil all the way.

Sarah: Yeah. Yep. And look, coconut oil is also fine. We're not saying that olive oil is the only one. A good virgin coconut oil has got nice fat profile as well. But in terms of the cooking, we've done a bit of research. Well, Modern Olive Lab in Melbourne has done a bit of research on this and I could share that with you. 

Essentially, the myth of the smoke point is really a myth in itself. There's actually no evidence showing that the smoke point of an oil correlates to any of the compositional oxidative breakdown or production of any harmful polar compounds or anything else. Somehow the industry got around...I think it's probably more of refined oil, industry got around by saying it's better than olive oil because it's got a high smoke point.

All that means is, the smoke point is measured by a subjective. If you and I measured smoke points, we'd get different values. You look at a machine, when a bluish haze starts to produce, that's when it's your smoke point. We all see it at different levels. And it doesn't mean anything. 

So the research we have done is looking at the oxidative breakdown of oils, the production of polar compounds, how stable the fat profile remains. And we look at smoke point going up, we don't see any correlation with those other things happening. So that's a myth we're still working on busting.

Andrew: I think my concern would be far greater in the use of meats. And we know that polyaromatic hydrocarbons released from meat, charcoaled meats. I mean, the newer evidence that's coming out says that it's not just in over-burning these meats, it's not just in the meat. It's actually in the vapours that come off and they land and they're absorbed in your skin. And I'm almost getting to the stage where I'm going to have to barbecue in a hazmat suit.

Sarah: No, you're right. And I think you've made a good point. People get so caught up, "Oh, the smoke point is low so I can't cook with it." I mean, it's [crosstalk 00:39:48] the olive fruit. I mean, people in the Mediterranean, they didn't even know what smoke point meant. 

And on your second point around… and I can share the published research on smoke point for you. The second point about nonstick pans, it's one I'm still kind of working through, to be honest. And I've gone to all of the main companies and had a look at their pans, went to shop one day, all the main ones say you can't use olive oil.

We did some research on that, which we presented at the Nutrition Society Conference I believe last year, and looked at what's actually happening, is there any interaction between the olive oil and the pan versus water versus all other oil types? And there was no difference at all. There was no leaching of stuff from the pan more or not. But I've had people tell me it ruins their pans. So I don't have any evidence to show why it might do that. But all I can say is, chemically, there's no issue with it. But it's a hard one to… how do you test that? I don't know.

Andrew: Well, do you know what it did for me? It actually made me barbecue more. Like, I now fry eggs on the barbecue and I don't have any problem with sticking even when I use olive oil. It still fries on the barbie.

Sarah: And some of the...I wonder if those nonstick pans...Yeah, exactly. Beautiful. And I think it's the quality. It's not about the oil. You mentioned it earlier. It's about the quality of the nonstick pan. Worry about what's on your nonstick surface. Don't worry about your oil that you're putting there.

Andrew: Maybe you should see my apron. We've spoken a few times about the Gold Star rating, and this is something that we need to highlight because this is an Australian first. There is suspicion about the star ratings on various foods, but I really think the Olive Oil Institute has done a massive, fantastic job on the Gold Star rating to do with olive oils in Australia, i.e. Australian-made.

Sarah: Thank you.

Andrew: Can we discuss that?

Sarah: Yeah. So the Health Star Rating, the issue with it with edible oils is that when they calculate the Health Star Rating, they do it based on the nutritional composition. So carbohydrates, protein, fats, sodium, we're missing one there, sugar. 

The issue with olive oil or oils is they've got nothing else but the fat. So what they do then is go down the minutiae of the calculator and the fats are calculated purely pretty much on the saturated fat component. 

So if an oil has slightly more by a couple of percentages of saturated fat, it gets a lower rating versus one that's highly refined with trans fats that gets a really high five-star rating. To put it in perspective, refined oils like canola oil, seed oils at the moment have a higher Health Star Rating than extra virgin olive oil and extra virgin coconut oil.

And to me, if the Health Star Rating's point is to help reduce chronic diseases in Australia and help consumers choose a more healthier product, it's not doing that in this category. So we put some petitions in for the five-year review. And after that review, they decided they'd still leave it as it was, status quo, but there's still a bit of lobbying and things happening in the background now for us to try and work with that. 

Because I would like to think, and one of the proposals has been, when you're calculating it for fruits and veggies and other foods, you can add positive attributes in for vitamins and nutrients in those foods, or biophenols, antioxidants, they should be one of those positive attributes. And you could put a natural one in extra virgin olive oil, versus a fortified one in a canola oil, that natural one should get higher points. We'll see what happens, but yeah.

Andrew: Wouldn't it be great to be able to claim a higher star rating based on biophenols and to maybe even put a quantity minimum biophenols?

Sarah: Yeah. And on that, some brands do actually list the amount. So you're looking for around 25 to 50 or 60 milligrams in 100 mls. That's what you want. You want higher amounts. The one you're having, I think it's got about 40, 45, depends on what year it was produced because it's natural products. Everything can vary. 

But my thing with that is that's not helping consumers choose a healthy product. That's just using a blanket calculator across all foods and not being adapting to it. So hopefully, we'll get some success with this next round of lobbying that we're working towards.

Andrew: Good. And obviously, this is all done from the Olive Oil Wellness Institute.

Sarah: Yes. Yes. We do a lot of this.

Andrew: Let's talk about when that was formed. Tell us a little bit more about what you're doing in the background.

Sarah: Yep. Formed in Feb 2018, so we're actually getting old. And we're very fortunate in that we are funded by one of Australia's biggest olive growers, Boundary Bend. But we do get a large portion of our funding through horticulture innovation. So we represent all olive growers in Australia. You won't see us promoting any brands on our website or throughout communications. It's around increasing knowledge around science, health, everything around that for consumers and health professionals in a credible way. 

We thought all these superfoods are out there getting these messages out, but extra virgin olive oil and the Med diet has a rich history of evidence of use. So we thought let's put that all together in one spot and make it really easy for academics, health professionals, consumers to get what they need. So leaflets on Can You Cook With Extra Virgin Olive Oil for you to give to patients.

Abir, one of my colleagues, created this amazing oil comparison tool that's now on the home page where you can choose up to four oils and get a really quick comparison of how they compare. So many things on there. So we're very, very fortunate in that we just secured another three years of funding through Hort Innovation up until March 2023. So we're extremely grateful for that. 

And it means we can get to doing things like, we're going to do a virtual sensory kit that helps you learn how to taste oils. We've got our podcast channel, we've got YouTube videos coming. So, so much more to come and very grateful that we've got the funding to enable us to continue with that.

Andrew: I like that virtual sensory kit. What I'd love see is a urinalysis-type dipstick where you could dip it into your oil and see if it was adulterated.

Sarah: That's a good idea.

Andrew: There's so much more to cover, but, Sarah, we're out of time. Sarah, I've loved speaking with you. I've learnt so much. I can get, though, that I have a lot more to learn about these, so I would love it if you would share some of this research that you've got up on the FX Medicine website. 

And for our viewers, if you've got any feedback, particularly our viewers overseas, if you've run into issues overseas - America, I know you have - but if you've run into issues perhaps in the European theatre and, indeed, if you know how to tell a good quality product from your country, let us know on FX Medicine, and we'd love to hear your thoughts. 

But, Sarah, thank you so much for taking us through the more intricate nature of olive oil and olive leaf extract on FX Medicine today.

Sarah: Well, thanks, Andrew. And I'm very grateful for your time. I loved chatting to you today and look forward to maybe next time.

Andrew: This is FX Medicine. I'm Andrew Whitfield-Cook.



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Sarah Gray

Sarah Gray is the General Manager of the Olive Wellness Institute, and is a passionate health and wellness professional, with experience in primary care settings, medical writing and food and drug industries. Sarah is a registered pharmacist and nutritionist with a keen interest in the active and phytochemical composition of foods, nutrients and natural/ herbal medicines, with a specific interest in extra virgin olive oil and olive leaf extract. She also works for the olive oil and olive leaf industry, providing education and driving research initiatives to strengthen science and awareness in this space. Her secondary interest is related to drug food and drug nutrient interactions. Sarah has been a sessional lecturer at Laureate/Torrens University for the past 5 years, specialising in Drug and Integrated Pharmacology.