Instant Genius - Avocados: Nutritional superfood or environmental disaster?

Episode Date: January 22, 2024

Since their first appearance on our supermarket shelves several decades ago, avocados have gone from being a mere exotic curiosity to a regular feature on many millennials’ breakfast tables. But how has this happened and what does it mean for our diets, the food industry and the environment? In this episode we speak to Honor May Eldridge, a food and farming expert and author of the book The Avocado Debate. She tells us about the avocado’s fascinating journey from everyday staple in traditional South and Central American cuisine to western superfood, how nutritious the fruit really is and whether or not we should feel guilty for eating smashed avocado on toast? Learn more about your ad choices. Visit podcastchoices.com/adchoices

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Need a hiring hero? This is a job for Indeed sponsored jobs. Some follow the noise. Bloomberg follows the money, whether it's the funds fueling AI or crypto's trillion dollar swings. There's a money side to every story. Get the money side of the story. Subscribe now at Bloomberg.com. This podcast is sponsored by name, audio, and focal. Streaming has made music more accessible than ever, but true listening is about more than ease. It's about quality. British audio experts name audio, alongside French, you can't. acoustic specialist focal, combine handcrafted tradition with cutting-edge innovation and high-end materials, delivering digital precision with analogue warmth. So you can experience exceptional sound at home. Music just as the artist intended. Visit name audio.com to learn more. Hello and welcome to Instant Genius, a bite-sized masterclass in podcast form. Each week you'll hear world-leading scientists and experts talking about the most fascinating ideas

in science and technology today. I'm Jason Goodyear, commissioning editor at BBC Science Focus magazine. Since their first appearance on a supermarket shelves several decades ago, avocados have gone from being a mere exotic curiosity to a regular feature on many millennials' breakfast tables. But how has this happened? And what does it mean for our diets, the food industry and the environment? In this episode, we speak to Honoma Eldridge,

a food and farming expert, an author of the book The Avocardo Debate. She tells us all about the fascinating story of the avocados journey from everyday staple in traditional South and Central American cuisine to a Western superfood. She also answers the question many of us want answered. Should we feel guilty for eating smashed avocado on toast? So we're talking about avocados. Obviously, most people will be familiar with these,

but we're a science brand. So I guess first off, what are avocados? Are they a fruit? Are they, you know, what are they? They're fruit. and they're from the Perseus brand. And what I find quite interesting about them is that they're very temperamental. So they're very particular about where they grow and how they grow.

And so that's kind of an avocado belt sort of runs around the world. But they're very particular about temperature and they're also quite thirsty. So they're very susceptible to frost and to the cold. So anyone who's tried to nurture an avocado plant through a UK winter might know how difficult. cold that is. And so that's one of the big problems with growing them. And they also take up quite a lot of water. So as we're going into an era of climate change with more extreme weather events and sort of disruptions, flash flooding and drought, you know, it's getting more complicated to keep avocado production steady. So we'll dig into that in a little bit, but let's continue looking at the thing

itself. Do they grow on trees? Like what does the plant look like? Yep. Nice tall trees. They are quite compact. They have quite a good canopy. What they actually do is they grow really well with the sort of detritus that falls onto the ground. So they sort of have that natural process of sort of building up the soil fertility underneath them. They have beautiful flowers that require pollination. And then these little green fruits appear. There are lots of different types, but they're kind of separated into sort of two main varieties.

So you have the kind of darker skinned ones that we need. more readily see in supermarkets across the UK. And then you have the greener skin ones, which are more associated with sort of West Indian varieties. So you mentioned something called the avocado belt. So where do they originate from? Where do they grow sort of naturally? So the first example that we know of is in Puebla, Mexico, which is a region close to Mexico city. It's got some highlands, so it's got some forest areas. And that's where we first see them, but they kind of spread from Mexico slowly outwards, but predominantly through Central and South America and also into the Caribbean. So today we're talking about your book, The Avicado Debate. I think it's

a good question to ask. What is your background and what led you down this path to produce this book? So I'm not a scientist. I'm a food and farming expert. So I was just really fascinated that the avocado has become sort of ubiquitous with the millennial generation. And there are all of these questions, you know, around, oh, well, you know, if you stop buying avocado toast, will you be able to buy our house? Like, you know, if you're a vegan but you're eating avocados, then you're killing the planet just as if you have a steak. And I couldn't really, when I was sort of sitting back and looking at this social side of it,

I couldn't think of any other fruit in history that had had such a part of the zeitgeist, I guess. And so that kind of led me into looking more deeply into how it had risen to such prominence, where it had come from, and all of the sort of forces at play that had led it to sort of peak avocado. Yeah, all the things were going to speak about in a bit. But to be honest, you say you're not a scientist. That sounds like science to me. I guess I'm interested in science. I always have been. And I think it's really pertinent. But to me, it's all of those things in how they interplay, you know, the economics, the history, the social,

the environmental, the science. It all kind of comes into this one little fruit. Let's go back into the avocado then. So one of the sort of big selling points, as far as I can tell, other than they are delicious, is that they're often termed as a superfood, which is kind of a bit of a floaty, nebulous term. So what exactly is the avocado's nutritional value? What are we getting when we eat one? So avocardos are really healthy. They have really good mixtures of vitamins and minerals. They are really valuable in terms of good fats. That's been a bit of a bumpy ride for the avocado. So in the kind of late 80s, early 90s, there was this really big dietary fad of being anti-fat. and that sort of stemmed out of really good intentions.

You know, dietitians, nutritionists, doctors were seeing body weights, increasing non-communicable diseases rising, and they wanted to halt that. And so they started to encourage people to have no fat or low-fat diets. And the avocado was one of the products that got hard with that brush. And so there were actually sort of recommendations, you know, don't eat avocados. They're too fatty. obviously now as the science has developed and there's more nuance we kind of recognize that there are good fats and bad fats and avocados have good fat it's really healthy for you it's not saturated so it means that it can keep you heart healthy and that it is really valuable obviously i'm not recommending that anyone eats like 10 avocados a day and that is it but they are a really valuable source of vitamins and minerals and that good fat we all need in our diet. Let's go back in time a little bit. People of my age, I'm in my mid-40s, probably first encountered

avocados as guacamole or something in a Mexican restaurant. I thought, oh, that's, you know, tasty, that's exotic. But traditionally, how much of a part do they play in the native people's food culture? So they are really important. And there is a long history of Mesoamerican involvement in avocados. They've been trying to sort of preserve them for the winters in order to keep that nutritional value because they do have that richness to it that we can all sort of recognize from our own taste of avocados. There's a long kind of history about how revered they were within sort of native communities and indigenous communities, pre-colonialism, and really had a strong place in the culture. They were considered to be quite the Afrodisiac

and Meso-American women were not allowed out in one area during the avocado. harvest because they thought that the pheromones of the avocado ripening trees would drive them all into insatiable lust. I don't know if we all believe that anymore, but that certainly does sort of permeate through this idea that they're a rather sensual fruit. And actually the Mexican word for avocado is in translation testicles. You know, they do look quite comical hanging from the tree. And that is how they aren't their name. So going from there then, from being this revered fruit in Mexican traditional culture, now you can get them in every supermarket in the UK and probably over most parts of the world. So how did that happen?

When did it really start proliferating like this? So when the Europeans arrived in Central and South America, they were at first very curious about the avocado. And there's a lot of stories about how they tasted them, what they thought about them. They tried to sort of pickle them and thought that that might give them a sort of taste of olives, like from home. They sort of exported them back to Europe and they were one of those exotic luxuries that some people had. But the big sort of turning point was really when they realized what an effective food they could be for enslaved people.

So they discovered that obviously with that rich fat in the avocado, that it could be a very caloric food for enslaved people. It didn't compete with sugar crops. And as I said earlier, they've got quite a compact canopy, which meant they could grow them on marginal land within the plantation setting without taking up too much space or depriving the cash crop and you could feed them to enslaved people. So as slavery sort of spread around the world with colonialism, the avocado followed. So you see it arriving in Indonesia, you see it arriving in Africa as that spread happens. And for a while, that was what it was. It was still sat in that indigenous food or enslaved people's food for a long time.

And then it arrived in the U.S. So in the very early part of the 20th century, avocado is arrived in California. So they've been grown a little bit in Florida, but not extensively. But they arrive in Southern California. and the growers start growing them and realize that this has the potential to be a really successful crop for the region. But at the time, there was quite a lot of racism and xenophobia. And they felt that something that was considered to be a Latino food was not going to be successful with white Anglo-Saxon housewives across America in the 20s. And so they do this sort of hilarious but very

conscious rebranding of the avocado. So they change the name. They say right now on it is only the avocado and they start placing it in recipes in vogue and in the New York Times and the New Yorker avocado toast sort of turns up as, you know, an appetizer de jure and it sort of moves rapidly from this Latino traditional food to this very luxurious item that kind of start to embody Hollywood California cool. So what other names did they go by? I didn't know that. They were called the avocado pair.

They were called the alligator pair. The alligator pair was probably the most popular one in the US. And they kind of figured that no one would want to eat something that was scaly and repellian. And so they sort of decided to change it and make it the avocado. Ambition comes in all shapes and sizes. At First Citizens Bank, we roll with your goals. because we're built for what you're building.

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But actually you're seeing a huge growth in China. So previously China didn't really eat any avocados. It wasn't part of the diet. But with that rising income and that desire to emulate Western diets, you're seeing that increase development. So there's a huge demand in China now, mostly being met by some African producers and Australian producers, Indonesian, but they're looking to develop their own market now and grow avocados domestically. So if that takes off, the production is going to skyrocket. So let's drill into that a little bit then. You mentioned earlier, I think you touched on

you said they're thirsty plants. So a lot of issues perhaps people have with them is the amount of water that they take to grow. So can you tell me a bit about that, please? Yeah, so they're super thirsty crops, but so are lots of fruit and veg and you see that, you know, tomatoes, almonds, pistachios, they all take up a lot of water too. So it's not that the avocado is disproportionately water intensive than some of the other crops. It's just that for some reason, it's really got labeled as such. So it does take up a fair amount, but it also is very dependent on the topography of where you're growing it. So Peruvian avocados tend to have a higher water footprint than some of the other regions, and that's just by virtue of where they're being grown. And that has a kind of knock-on

effect to communities. So when we're talking about avocado production, a lot of the time we're actually really speaking about one region in Mexico that grows 90% of the world's avocados. So most avocados in the world are grown in Moshuakan, which is southwest of Mexico City. And water is being taken away from local communities in order to be diverted into the avocado plantations. And so, yes, they're thirsty, but it comes also with this tension around community values and the sort of justice aspect of the water being diverted away from people. So I might be being a bit trite in drawing this comparison, but when I was younger, people would often talk about beef production in the Americas, like logging environmentally vital

resources, such as the rainforests in Brazil, for example, for the local people to produce beef. I mean, is that comparable to the situation we have now with avocado farming? To a certain extent, yes. So you are seeing areas of native forest being cut down. You are seeing slashing burn, agriculture emerging. What tends to happen is it's actually a secondary step. So it's not that forest is being cut down for avocados. It's that the subsistence farmers, their land is being transferred into avocado orchards because it's more lucrative. And then those subsistence farmers and community growers are moving into the native forest. So it's difficult to see.

say avocado plantations result in native forest being chuffed town. But what it is is that incremental creep as people move out. So would you say they've developed a sort of monoculture? And if so, how does that affect biodiversity? So yes, it is monoculture now for avocado plantations, particularly in Mishoacan, other regions too. But Moshua Khan is one of the most biodiverse regions of the world, let alone in Mexico, and they actually have a biosphere sort of national park, which cohabitates the land with these very intensive avocado orchards. And on that biosphere, you've got jaguars, you've got incredible bird life, you've got amazing native pine forests, and you've also got the monarch butterfly. So one of the breeding grass, monogne, butterfly, is in

Meshawakhan adjacent to these plantations. And so that's really having a knock-on effect as that land use is changing. You've also got the added impact of pesticide and fertilised applicants. In some ways, avocados have less pesticide load than other products. It's one of the cleaner foods in terms of pesticide residue. And that's mainly because it's got that incredibly hard skin, you know, that is really resilient to pests. So you don't need to apply as much. But obviously, if you're growing it in a monoculture, there's not very much natural resistance and disease can spread really, really quickly. So you are seeing that kind of increasing level of pesticides as a sort of crop protection. Similarly, fertilise the usage. If you constantly are harvesting from the same region,

that soil fertility gets depleted really quickly. And so they're putting it back in. And so, through synthetic fertilizers. Again, not as much maybe as some other crops that we can think of like soy, but you are seeing it and that fertilizer can leach into the groundwater and pollute waterways, which when we've got communities that are already fairly water stressed, can really aggravate the situation. So I mentioned the logging there earlier and the beef and things. So this is something a lot of people are thinking about now, the environmental impact of the food that they consume. So what exactly is the environmental impact of avocados and how does it compare to other food sources? Well, the thing is, every food that you eat is going to have an environmental impact, good and bad.

And so you need to really consider all of them in the round and really understand the complexity of food production. And that's what I hope my book tries to do is unpick this really complicated situation just with one product, you know, and look at all of the impacts that avocado production can have. But I think, you know, we tend to end up in this sort of rather binary conversation around, well, are avocados good or bad? Well, they're both. You know, is beef good or bad? Well, it's both. It depends on how you grow it. If you grow avocados in a monoculture plantation style with a load of chemicals with very little community involvement and, you know, with some of these other risk factors, yeah, it's going to have a really detrimental impact on the environment, if you're trying to source your avocados from more sustainable producers,

small scale, mixed farming that's trying to farm in harmony with nature or at least not damage it, then it has a much smaller impact. You've kind of answered that already in a way, but as you say, your book is sort of talking about fundamental issues with the food production system seen through the lens of avocado agriculture. So having said that, what do you think, are the key problems that we're facing? The primary focus that we're facing at the moment is how to increase production to meet a growing population globally while still protecting our environment. We can ramp up production, we can ramp up yields, we can use all the technologies at our disposal,

but you risk in doing that, damaging the environment and so ultimately pushing that problem down the line and creating more of a knock-on impact where the soils, are degraded, the land is degraded, you've seen land use change and we lost those areas of spectacular natural beauty and natural biodiversity. So I think that that's kind of one of the big tensions. And obviously we're talking about that increase in population against the background of climate change. So you've got that issue where it's getting more difficult to farm. We're getting more extreme weather events and that's really challenging. So is there a more efficient way that we could be doing this. You know, you talk about GM food, for example.

I mean, people are talking about whether you could gene edit the avocado. So one of the high levels of food waste is when avocados go brown. I think anyone who's cut up an avocado and then not use the whole thing, then comes back to it an hour, two hours, three hours later, and it's kind of gross. You chuck it out. And so just like they attempted with the Arctic apple to make a kind of non-browning apple. People are exploring whether you could create a non-browning avocado and whether that would help address food waste and reduce the number that get chucked out. Similarly, you know, there are pests that are particularly detrimental to avocados, you know, there's a sort of blight that potentially could really disrupt production.

And so could you create a resistant avocado? The question then quickly becomes, though, around those technologies and the ownership of those technologies who would have the kind of means of production in that instance. As I said, you know, 90% of global apricadas come from Mexico. Mexico is currently trying to ban GMO inside of their borders. So while these technologies might be able to be developed, how they would be able to be used and what the legal ramifications would be for what is essentially a kind of global. trade, would you want to run that risk if you can't import them into China? If you can't import them into the European Union, is it worth it? Perhaps it's for some producers and it wouldn't be for

others. So this is kind of my closing question. It's a bit of a tufa. So having said all of this, say somebody listening is an avocado fiend and they didn't realize all of the complicated processes that happen before one comes on their shelf in the UK. One, should we still be buying avocados from the supermarket. And two, are there any alternatives that we can choose instead? So I think, yes, you can still buy avocados. I still buy avocados. I don't think anyone should be giving them up. If you're an avocado fiend, maybe think about when and how you're using them. Maybe they're a Sunday brunch thing and not a Tuesday throw it in the salad mindlessly option. So just being a bit more judicious with the usage. And as I said, starting to really understand that

impact and where it comes from. In terms of how you choose a more sustainable avocado, you know, there are options, there are certifications out there of avocados that have been produced to certain standards. To my mind, that really depends on what your personal concern is and what you take greatest concern in. So if it's the environmental side, you probably want to be trying to buy avocados that have organic certification. If it's the social side, then maybe you're opting for a fair trade one. If it's the footprint and the food miles that it's traveled, we've got some really great European avocados being produced not so far away now, and you can choose to get one from Spain or from Greece. So I think there are some steps that you can take,

but again, it's understanding what your concern is and what you prioritize in your food choices. Obviously, all of those certifications make the avocado more expensive, and so therefore it can become cost prohibitive for people. But I think that that's one of those ways in which you can start to really make a difference in your food choices. In terms of alternatives, lots of people have come up with some really interesting ones. So there are mainly it's peas, really. So in the UK, a really good option is sort of a glorified version of mushy peas instead of your guacamale looks the same in terms of the colour. And you can put in some really great flavours. And I Obviously, we grow peas and beans very well in this country,

and they are very good for soil health because they bring in natural nitrogen into the system. So I'm a big fan of doing that, but obviously you can't quite emulate the taste and the sort of butteriness of an avocado in quite the same way. So I really understand if people want to stick with avocado on toast instead of peas. Thank you for listening to this episode of Instant Genius. Brought to you from the team behind BBC Science Focus.

That was Food and Farming expert and author, Honam A Eldridge. The current issue of BBC Science Focus magazine is out now. Pick up a copy wherever you buy your favourite magazines or download us on your preferred app store. You can also find us online at sciencefocus.com. This podcast is sponsored by Name, Audio and Focal. The texture and emotional depth of music can be lost through digital sources or poor signal. Name Audio believes you can have digital. digital precision with analog warmth.

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