This is a transcript of the Gastropod episode Peanuts: Peril and Promise, first released on June 20, 2017. It is provided as a courtesy and may contain errors.

(PEANUT SONGS AND ADS)

CYNTHIA GRABER: This makes me feel like a kid again—I ate peanut butter all the time growing up, like most kids did in the 70s and 80s in America.

NICOLA TWILLEY: I had a year of kindergarten in the U.S., so I was familiar with the magic of a PB&J from lunchbox trades. But then I moved back to England, and I didn’t have peanut butter again till I was 16. I was babysitting the kid of American expats. They had Jif in their kitchen cupboard, and I ate a spoonful… and oh my God, there I was standing there in suburban Surrey, it was like Proust and his madeleines. I was basically five again. Peanut butter apparently goes deep.

GRABER: And, as usual, we are going to go deep this episode—all about the peanut. You’re listening to Gastropod, the podcast that looks at food through the lens of science and history. I’m Cynthia Graber.

TWILLEY: And I am Nicola Twilley. And this episode, we are going to find out where the peanut comes from, explore the controversy over who invented peanut butter…

GRABER: As well as investigate the mystery of why so many people are suffering from peanut allergies—and we’ll find out how peanuts are also helping save lives by tackling world hunger.

(PRE-ROLL)

(MUSIC)

JORI LEWIS: No, peanuts are not nuts. They are legumes. So they are more related to, like, soybeans or mung beans or something like that than they are to tree nuts—almonds or walnuts.

TWILLEY: So really today we’re talking about the pea bean.

GRABER: That doesn’t sound nearly as exciting.

TWILLEY: We can keep calling it the peanut if that sounds better, sure. But either way, the peanut is an exciting plant.

JON KRAMPNER: The peanut is about the only plant in the world where it flowers above ground and it fruits below ground.

GRABER: Jon Krampner wrote the book Creamy and Crunchy: An Informal History of Peanut Butter, an all-American food. And Jori Lewis—she was the first person you heard—she’s a freelance reporter based in Senegal, and she’s working on a book on peanuts and the slave trade.

TWILLEY: We don’t tend to think about peanut flowers, but, according to Jon and Jori, they’re beautiful. Jon described them as almost like orchids, with little orange and red streaks.

KRAMPNER: After about a day or so the flower dies and what’s left is what’s called a peg, which turns downward, burrows into the ground, and then produces a peanut underground.

TWILLEY: And that is just plain weird. Like Jon says, the peanut is almost the only plant in the world that does this whole flower-then-burrow routine.

GRABER: The peanut is native to northern South America. Scientists think people have been growing and harvesting peanuts there for about 10,000 years. Peanuts are used to make soap. They’ve also been used in all sorts of dishes. When peanuts are young, people eat them shell and all. They’re also used for peanut juice, a drink that also includes fermented quinoa water. I totally want to try that.

TWILLEY: You first. But, you know, if we’re talking about trying traditional peanut recipes from South America, Jon has a slightly better sounding option.

KRAMPNER: The ancient Incas ground peanuts and mixed it with chocolate. I guess it’s kind of like their prehistoric form of Nutella or something.

GRABER: Then peanuts spread into Central America as well. But today people all over the world eat peanuts, peanut butter, peanut oil, peanut sauce. So how did these tiny beans travel around the world? First, of course, the Conquistadors showed up in South America.

TWILLEY: And, unlike cacao beans, which, as you might remember from our chocolate episode, were not necessarily a hit with early European invaders, peanuts actually went over pretty well.

GRABER: One of the first recorded sightings was by a priest named Bartolome de las Casas who traveled to the island of Hispaniola—it’s now Haiti and the Dominican Republic—in 1502.

LEWIS: And he said that they grew this thing that grew underneath the ground that tasted like a hazelnut. And that’s kind of the perception that repeated quite often by many of the explorers. They kind of find this thing that Indians grow and that they eat, that tastes like a hazelnut.

TWILLEY: So, basically, peanuts were enough like something the Europeans already knew from back home that they embraced it with open mouths. And the peanut had some other important benefits to a sea-going people.

GRABER: When they’re dried and roasted, peanuts keep for a really long time. And they’re an amazing source of protein, and they’re delicious.

TWILLEY: Which makes them an amazing food to take on long sea voyages.

KRAMPNER: The Spanish took peanuts west to Asia on galleons that sailed between Acapulco and Manila between 1565 and 1815. The Portuguese took it to east to Africa and India from their colony in Brazil.

TWILLEY: Peanuts became popular basically wherever they went. But in Western Africa, they really caught on. Because pretty much the only other plant that grows like a peanut, with this weird flower-above-ground-fruit-below thing is an African plant called the bambara groundnut.

LEWIS: So Africans would have had experience already growing something similar.

GRABER: They grow the same, but they don’t taste exactly the same.

LEWIS: No, like, peanuts are kind of almost slightly sweet. The bambara groundnut doesn’t have that. It is kind of like eating like a pea or a bean or something like that. Although you do eat them in the same way, like, with boiled, with salt, or like roasted.

GRABER: Peanuts have other advantages, not just that they’re sweeter and more nut-like, less beany. They have a higher oil content and peanut plants produce more nuts than bambara groundnuts do.

TWILLEY: So peanuts became all the rage in West Africa, and, from there, they made their way back across the Atlantic to the U.S.. Most historians think they came on slave ships.

LEWIS: There have been some scientists who question this hypothesis, right? Like why wouldn’t the peanut have crossed like Rio Grande. You know, like, it was in Mexico, why not? But I guess the evidence doesn’t show much usage by Native Americans.

GRABER: The argument that peanuts came with the slave ships seems pretty convincing. We already know peanuts were used to provision ships, and the slaves themselves also likely brought the seeds with them. Because they were growing and eating peanuts in West Africa.

TWILLEY: You can even trace the West African origins in the different names people have for peanuts in the South.

LEWIS: In the South for a long time called the peanut the goober, and we know that goober is a derivation of a Congolese word called nguba probably for the bambara groundnut, right? For something that’s like the peanut.

GRABER: Peanuts really suited the South. The sandy soil there was a perfect home. And the plant, like other legumes, helped enrich the soil. So people grew them—but you wouldn’t find them on the dinner plates of the rich families in town.

KRAMPNER: Peanuts were more traditionally thought of as just something that you fed to the hogs, really. They, sort of gastronomically, you could say they were lower on the social scale.

GRABER: This is actually where the phrase ‘peanut gallery’ comes from. The cheapest and rowdiest seats.

TWILLEY: It took multiple wars for peanuts to turn their image around in the U.S.. The first was the Civil War

KRAMPNER: In the Civil War, when the Union blockaded the South, Southerners had to turn more to peanuts as a way of just surviving. And, in a sense, you could say an early form of peanut butter, they would put peanuts in a bag and shake them around and make what was called peanut porridge.

GRABER: And then as the Northern soldiers marched through the South, they got to know the peanut. For many, this was their very first encounter with our national bean.

TWILLEY: Just you wait, you will all be calling it the pea bean by the end of this show. Post-Civil War, peanuts got another huge boost when the super ugly, snouty boll weevil made its way up from Central America and ate all the Southern cotton crop.

KRAMPNER: And so southern farmers had to look for a replacement crop. They turned to peanuts and then they thought, well, we’re not going to really get much money selling all of this for hog food, how can we make a more lucrative crop out of them?

GRABER: But the farmers had a problem, because the peanuts had an image problem.

KRAMPNER: They also had to, in a sense, engage in a PR campaign of convincing Americans that peanuts were not just this hog food anymore. And so you get an article in the 20th century where you you see a peanut with a top hat and monocle and spats, and it’s like an early forerunner of Planters Mr. Peanut. But this is their way of saying that peanuts are now a high class food for people.

GRABER: That little top hat and monocle made all the difference.

TWILLEY: Not as much difference as grinding the peanuts into a gritty paste, which is what happened next. This new era in peanut history began in the Midwest in the 1890s.

KRAMPNER: And there are two different schools of thought as to who made the first peanut butter. One school says it was John Harvey Kellogg of the Kellogg’s cereal family.

GRABER: We’ve talked about John Harvey Kellogg before. He ran a sanitarium in Michigan, and it was filled with lots of weird and not particularly tasty foods. And he loved the peanut. It was an ingredient in his meat substitutes. And he turned it into a paste, kind of like what the Incas did.

TWILLEY: Unlike the Incas, Kellogg patented his paste. But the Inca chocolate version sounds way better than the healthy Kellogg version.

KRAMPNER: Originally they would kind of roast peanuts but then they decided that it made more sense to either steam or boil them because it was healthier. And it is healthier, but the taste isn’t as good. Which is why some other people think that really credit for starting peanut butter goes to George Bayle.

GRABER: George was a snack food manufacturer in St Louis. He made potato chips, called Saratoga chipped potatoes. He made horseradish sauce. And unlike John Harvey Kellogg, he roasted his peanuts before he turned them into a paste so they actually tasted good.

KRAMPNER: The flavor of peanut butter is the flavor of roasted peanuts. So that’s why I’m a George Bayle man.

TWILLEY: To be totally fair here, George’s first peanut paste sounds as disgusting as Kellogg’s boiled concoction: it was called Cheese-Nut, and, just like it sounds, it was a Cheese Whiz-substance flavored with peanut butter. According to an April 1920 article in the Peanut Promoter magazine, Cheese-Nut was quickly dropped. But peanut paste solo—that caught on.

GRABER: By 1914, there were already more than twenty peanut butter brands for sale in Kansas. It was a hit in sandwiches. The first peanut butter sandwich recipes in the late 1800s were often more savory. They had mayonnaise, Worcestershire sauce, cayenne pepper. Maybe some lettuce or even meat. Personally I think these sound kind of tasty.

(PEANUT BUTTER AND JELLY SONG)

TWILLEY: Peanuts didn’t first meet their life partner, jelly, until 1901. But it was love at first sight. And then when sliced bread was invented in the 1920s—well, there was no stopping the PB&J after that.

GRABER: The two World Wars gave peanuts a major boost. During the First World War, Americans were told to lay off the meat so that it could be sent to soldiers, and so they turned to peanut butter for protein. But in the Second World War, peanut butter was included in the soldiers’ rations. It’s high in protein and calories and all sorts of great nutrients.

KRAMPNER: And the soldiers really took a liking to it. Plus they came back and fed it to their baby boomer kids. And that’s when sales of peanut butter really started to skyrocket.

TWILLEY: Today, Americans eat a lot of peanuts. And roughly two thirds of the peanuts we eat are in the form of peanut butter.

GRABER: But—and this is somewhat shocking—there is another country that eats more peanut butter per capita than we do. Canada, you win on this one.

TWILLEY: In Europe, the Dutch are a bit of an anomaly in that they actually eat almost American levels of peanut butter. They call their peanut butter pindakaas, which is peanut cheese.

GRABER: But not George Bayle’s Cheez Whiz variety.

TWILLEY: No, thank god. Although the Dutch do have a soft spot for savory uses—PB and cucumber sandwiches are popular, apparently, as is peanut satay sauce. Maybe a legacy from when Indonesia was a Dutch colony.

GRABER: In India and China, peanuts are popular, but almost exclusively for peanut oil. It has a high temperature frying point and so it’s perfect for stir fries, even better than the oils that were being used before peanut oil, because they were smokier.

TWILLEY: But with the exception of our friends in The Netherlands and Canada, the U.S. really does have kind of a unique relationship with peanut butter.

KRAMPNER: Americans are, you know, we’re kind of impatient, we want things now. And peanut butter is a fast food: you open a jar, you eat it. It’s not like, you know, you don’t have to have a Japanese tea ceremony or anything.

GRABER: I personally will eat peanut butter on almost anything, no need for any type of ceremony. On apples, on carrots, whatever, it’s great. But the rest of the world thinks Americans are pretty weird.

KRAMPNER: As children we become accustomed to its sticky texture, whereas in other countries where they don’t grow up on it, people who were introduced to peanut butter as adults don’t like the sticky texture.

TWILLEY: Speaking of texture, that’s one of the ways that peanut butter has really evolved since George Bayle’s day. At first, grinding peanuts in the mechanical food mills of the time gave a sort of coarse, grainy texture. A little bit like the texture of grind-it-yourself peanut butter in grocery stores today.

GRABER: And then came hydrogenation. You’ve probably heard about hydrogenated vegetable oils—basically hydrogen gas is bubbled into a big tank of oil that has another substance in it, a catalyst to make the reaction work. Hydrogenation changes the bonds of the atoms in the oil so that it stays more tightly packed, more solid, and that also means it has a higher melting point. So it’s solid at room temperature.

KRAMPNER: And you get the first hydrogenated peanut butter, which is Heinz, by the way, in 1923.

GRABER: Adding some partially hydrogenated oil meant that the peanut oil didn’t separate and rise to the top of the jar. And so it didn’t go rancid. And you could keep peanut butter out of the fridge for longer.

KRAMPNER: Prior to that, most peanut butter brands were local and regional. But with hydrogenation you could you could ship the peanut butter around the country. It would last during shipping, it would last, you know, on the store shelves. And so that really helped to fuel the rise of national peanut butter brands.

TWILLEY: And it was the key to the rise of super creamy peanut butter—the kind most people grew up with, the kind that’s almost like frosting. Hydrogenation is what makes that texture possible. And we should say here, hydrogenation sounds a little scary, but only 1 to 2 percent of the final jar of peanut butter is this hydrogenated oil, and an even smaller percentage of that contains transfats.

GRABER: So that’s how our peanut butter got super smooth and creamy. But how did it get crunchy? It all goes back to a guy named Jerome Rosefield. His father created Skippy.

KRAMPNER: Jerome Rosefield would travel around the country a lot, he would ask people, “How do you like our peanut butter?” And if they didn’t like it, he would ask why. And the most common response he got was that, well, it’s too smooth. And this just appalled him because we’re trying to make our peanut butter as smooth as possible. And here are people complaining it’s too smooth. But he goes, all right, if that’s what they want.

GRABER: So in 1935, they made some crunchy peanut butter to test out in Salt Lake City. After making the smooth variety, they just threw in some partially ground peanuts as well. It was also a hit. Not as big a hit as smooth peanut butter, but it has its place. Seventeen percent of peanut butter buyers prefer the crunch.

TWILLEY: I am a crunchy girl myself, I must admit.

GRABER: This is how we ended up with the peanut butter textures on the shelf today. We have crunchy or creamy. The first peanut butter really wasn’t either one.

TWILLEY: And those first peanut butters—the taste would have been different too. Because it turns out there’s four main varieties of peanut, and they all taste different.

GRABER: Today nearly all peanut butter comes from one variety—it’s called the Runner peanut. But in the past, nobody made peanut butter out of Runners. It was made from Spanish or Virginia peanuts, which are two other varietals. And the fourth type of peanut is called the Valencia.

TWILLEY: The Spanish are the little red-skinned ones you see sometimes, they’re sweeter and smaller and today they’re mostly used in peanut candy. Virginia are the largest, they’re called the cocktail peanut—when you buy jumbo roasted salted peanuts, those are Virginias, and so are the ones you have to crack yourself at the ballpark.

KRAMPNER: There are differences in oil chemistry between the Spanish and Valencia on one hand and the Runners and Virginias on the other. That really is what accounts more for the difference in flavor.

KRAMPNER: The Valencias are really the sweetest, closely followed by the Spanish but the Valencias are the most the most trouble to grow, you could almost say the most temperamental.

GRABER: So as I said, for all of peanut butter’s early history, the manufacturers used mostly Spanish or Virginia, or both. Valencia was a pain to grow. And the Runner? That was just thought to be a kind of crappy peanut. Until 1970 and the Florunner.

KRAMPNER: Well, the Florunner was just a revolutionary kind of peanut. And the Florunner was developed by a peanut grower at the University of Florida. So its name comes from the state of Florida and the fact that it’s a Runner. Now, Runners traditionally have not been regarded as tasty as the other varieties of peanuts. But the Florunner was tastier than previous runner varieties. It also had the virtue from the point of view of peanut growers of being much more prolific, by about 25 percent.

TWILLEY: Farmers obviously loved that aspect of the Runner. And manufacturers loved that the nut was more uniform, so it roasted evenly. But they were nervous—would peanut butter eaters who were used to Virginia and Spanish nuts, would they like the taste of the Florunner?

GRABER: Jif tested the waters by adding just 15 percent Florunner into their peanut butter. Nobody noticed. So all the companies started adding more and more, until Runners became basically the winner in the peanut race. And they still are today.

TWILLEY: All the major peanut butters—Jif, Skippy, Peter Pan, the self-grind stuff in the store—it’s almost all Runner. That’s the taste we’re used to now. But the Florunner takeover in the 70s means that, if your grandad says peanut butter doesn’t taste like it used to, he might have a point.

KRAMPNER: Regardless of what the manufacturers say, I and partisans of other varieties of peanuts feel that it did change the flavor. It’s a little blander now.

GRABER: So we decided to test this out. We’d never even considered the fact that there might be variety in peanut butter other than, you know, added sugar or not. I mean, peanuts are just peanuts, right? But it turns out there are a few companies that still use peanuts other than Runners. They’re hard to find, but they’re out there.

TWILLEY: So we assembled four peanut butters and two quote unquote volunteer taste testers—Cynthia’s partner Tim, and my husband Geoff. Really, they have no choice, this is what you get for living with Gastropod. But they have qualifications in this area.

GEOFF MANAUGH: Sure, my name is Geoff Manaugh and my relationship to peanut butter… I guess you could call me peanut curious.

TWILLEY: But I mean you are peanut experienced too, at least as a youth right?

MANAUGH: That’s true. Yeah I’m peanut experienced. I grew up—if I remember correctly I ate Skippy. My mom would make me peanut butter sandwiches, not peanut butter and jelly. I’m not a big jelly fan. And then I honestly don’t eat peanut butter very often but I guess when I do I enjoy the experience.

GRABER: I would like you to describe for me your typical breakfast.

TIM: For as many years as I can remember, it’s a piece of toast and peanut butter with honey on top of it.

GRABER: Did anything in particular start this breakfast routine?

TIM: You know, I was trying to think about that in advance of this and I couldn’t remember. It’s just, it’s like the perfect breakfast. You don’t have to think about it. It’s easy to make. It’s really filling. It’s really yummy. It’s the best breakfast!

GRABER: And what did our intrepid peanut tasters think about these new horizons in peanut butter? We’ll find out—after we hear from a couple of our sponsors this episode.

(MIDROLL)

TWILLEY: Time for some peanut butter. Our first jar was one we had to order by mail—Krema Nut Company from Columbus, Ohio. They use only Spanish peanuts.

TiM: Totally tastes like Spanish peanut, right? So my dad used to get the bags of Spanish peanuts and it still had that outer skin on them. They were red.

GRABER: How do you know they were Spanish?

TIM: Because it said Spanish peanuts on the back. And this tastes just like that.

TWILLEY: Krema Nut has no added sugar. But Spanish peanuts are known for being naturally super sweet. And you could really taste that. I keep wanting to say like, floral, but, I mean, this is not a wine tasting, this is a peanut butter tasting.

MANAUGH: Are you having trouble talking?

TWILLEY: Glues your whole mouth together. That’s very sticky. It’s quite mild, nutty, quite sweet—it’s got a lot of—it’s honey, it’s honey that I’m thinking of. It’s kind of got a honey-ish note to it.

GRABER: The next one we tried was Valencia. Trader Joe’s has an organic Valencia peanut butter. And like the Spanish, it’s known to be sweeter. And it’s higher in oil.

MANAUGH: Alright, so I’m looking at it, it’s very, very liquidy. In fact it’s kind of it’s actually moving around quite actively inside the jar.

TWILLEY: When you shake it, it’s not like it’s alive.

MANAUGH: Well, I’ll be the judge of that.

TWILLEY: Geoff and I were not fans of this one. Geoff compared the taste to flat Coke.

GRABER: Tim and I actually loved it.

TIM: Yeah it’s sweeter and it has felt like almost like a—like a coffee flavor or something. It’s this smoother nuttiness or something.

GRABER: It’s a different flavor profile. I have to say I’ve always loved the Runner peanut. It tastes fine. But now that I’m tasting these other ones, it doesn’t taste as good. Am I getting spoiled?

TIM: That’s it. Now we’re going to have to get mail-away peanut butter every week. That’s terrible.

GRABER: Good thing that Trader Joe’s isn’t so far.

TWILLEY: You can keep your Valencia. In our house, it’s all about the Virginias. That was our third peanut butter: Koeze Cream Nut from Grand Rapids, Michigan.

MANAUGH: There’s definitely a strong peanut taste and yet it’s not sweet and yet it’s also kind of, I don’t know, it just tastes really good. I like it. So what kind of peanut is this again?

TWILLEY: This is the Virginia.

MANAUGH: Go America, man.

TWILLEY: Exactly. That’s exactly the moral of this story.

GRABER: This one wasn’t our favorite.

TIM: It doesn’t seem that different for me than the Runner.

GRABER: And actually they’re in the same, like, when they’re grouped together in the varietals, it’s the Runner and the Virginia and the Spanish and the Valencia.

TIM: Look at us we’re like sommeliers of peanut butter.

GRABER: It’s totally true.

TIM: I want that to be a thing. And I want to be the first master peanut sommelier. Now I can close my eyes, blindfolded. First I smell, then I taste, I can tell you this was a Valencia grown at 5000 feet above sea level.

GRABER: Oh my gosh, Valencias are grown higher above sea level in New Mexico! You’re not even kidding. That’s totally true!

TIM: I’m the peanut whisperer!

GRABER: Tim’s been eating peanut butter every morning for breakfast for like a decade—and he is clearly a peanut butter expert! Okay, so the Valencia bit was a good guess. But it is really grown at 4000 feet in the US.

TWILLEY: This whole thing, even though I felt ridiculous doing a peanut butter tasting—but it was one of the more surprising taste tests we’ve done for the show. I really was expecting peanut butter to just be peanut butter. But now I’ve sold my soul to Virginia peanuts, and I can only get my peanut butter in the mail from now on, which I am perfectly aware is about the bougie-est thing I’ve ever said.

GRABER: This is a fun one to test at home, and if you go to our website—gastropod.com—we’ll have the names of the peanut butters we used. But not all of you will be able to give it a try. Because I’m betting that some of you listeners either are or live with someone who’s allergic to peanuts.

MATTHEW SMITH: So the first medical case that I’ve come across of a peanut allergy fatality is in the Canadian Medical Association Journal in the late 80s. And a couple of months later there’s one in the Journal of the American Medical Association. And then there’s a few more reports. And it just escalates from there, and it escalates very quickly.

TWILLEY: Matthew Smith is a professor of health history at the University of Strathclyde and the author of a new book called Another Person’s Poison: The History of Food Allergy. And he told us that the number of people who are allergic to peanuts has basically doubled in the past 20 years.

SMITH: So we’re talking about something that starts in the late 1980s, and has continued to increase. Now that’s not to say that there weren’t cases of peanut allergy or even fatal reactions to peanut allergy before then. There are a few that you can come across, although hardly any, if any at all, in the medical literature. But what you do see is this this rapid increase during the late 1980s, and throughout the 1990s. So the question is, yeah, if people were eating peanut butter and peanut products, Snickers bars and all the rest of it, throughout the 20th century, which they were, what changes in the late 1980s and 1990s and onward to today to explain the increase in peanut allergy?

GRABER: Right. It’s weird. People have been reacting to food since, well, as long as we’ve been eating food. We haven’t always called it an allergy.

SMITH: The word allergy goes back to 1906. Prior to that we do get discussion of what are called idiosyncrasies, which basically means a strange reaction to something. And that, certainly, you can get cases of idiosyncrasies to food all the way going all the way back to Hippocrates—so you know, fifth century B.C.. He talks about cheese being something that gives some men great strength but others come off badly. And we can just imagine what come off badly means.

TWILLEY: But the thing about these idiosyncrasies or allergies as we know them today, it’s hard to get a handle on them. Some data says 60 percent of Americans suffer from a food allergy—other people think that number is wildly overblown. It comes down to a fuzziness in how you define an allergy. But an allergic response to peanuts—I mean, anaphylactic shock is not a particularly fuzzy thing.

SMITH: So what happens to many people when they have a peanut allergy reaction is that they go into anaphylaxis. Which is a way of the body in a way going into shock. So it sends the immune system into overdrive. So if you think of your body comes in contact with a cold virus, what the body does is it triggers all of these antibodies to try to attack those cold viruses and prevent them from entering the body. So you get, you know, phlegm-y, mucus-y, start sneezing, all those sorts of things. Those are all defense mechanisms. Well, what anaphylaxis does is it basically does that times a hundred. So you get swelling in the neck, for example, that’s one of the most dangerous symptoms. You also get drops in blood pressure. You tend to get cardiac problems. Your body is just going into overdrive trying to prevent this peanut protein from entering the bloodstream essentially.

GRABER: Basically your body thinks that the peanut protein might be something foreign that it has to get rid of. This is how most food allergies work—there’s a protein that your body freaks out over.

SMITH: In terms of what makes peanuts the reactions to peanut more potentially fatal than, say, to other proteins, that’s something that scientists are still trying to find out.

TWILLEY: And that’s not the only unanswered question here. The thing in your body that makes it freak out, that’s a chemical called immunoglobulin E, IGE for short.

SMITH: One of the mysteries is what was IGE for prior to allergy? In previous centuries when allergies weren’t such a common occurrence, what was this IGE for? And one of the hypotheses seems to be fairly well substantiated is that IGE was used to fight off parasitic infections.

GRABER: This actually leads to one of the hypotheses for why allergies in general might be on the rise. It’s called the hygiene hypothesis. Basically it’s that we live in such a clean environment and our bodies aren’t exposed to parasites and other types of infections that might toughen us up, and so that IGE has nothing to do and so it overreacts. To peanuts, and to other foods. You know, allergies.

TWILLEY: But the hygiene hypothesis doesn’t answer the question of why peanut allergies in particular are seeing such a stratospheric rise, more so than other allergies.

SMITH: If I was a scientist with the American Allergy Association, you know, the honest answer would be we don’t know. But there certainly have been a lot of hypotheses put forth.

GRABER: One of these hypotheses is that there are more peanut allergies in areas of the world where they—we—roast the peanuts. And that maybe roasting affects the peanuts in some way that boiling doesn’t and makes them more allergenic. So maybe John Harvey Kellogg was right? But I don’t want to eat boiled peanut butter.

TWILLEY: Matthew said there’s another, quite controversial hypothesis, that’s still very much speculation.

SMITH: And that is that the idea that pharmaceutical companies have been using peanut oil as an adjuvant in their vaccines for about well put the same number of years as peanut allergy has been a problem. That’s something that I think given all the fuss about MMR and autism, you know, if you’re a respectable scientist who wants to have a decent career you’re probably not going to go near that one.

GRABER: There’s another theory, and it kind of wraps up two ideas in one. It’s that there’s peanut protein in so many things—peanut butter, peanut flour, peanut oil. It can show up in deli meat, the additives in orange juice, chocolate, everything.

SMITH: What’s interesting or what I guess is alarming about peanuts is that they seem to enter the food stream in ways that certainly seafood and maybe not eggs but other products don’t.

TWILLEY: So Matthew’s point is peanut proteins are everywhere in tiny, tiny quantities. And, at the same time, the advice to parents has often been to not introduce peanut butter until kids are a little older. So they’re getting this low-level background exposure and then not encountering an actual peanut until much later.

GRABER: And the hypothesis is that means that your body never learns to deal with the peanut, it just always thinks that peanut protein is a that foreign substance that kicks IGE into high gear. Today, the guidelines for when to introduce peanuts has changed. Now, if kids don’t seem to be at high risk for food allergies, the recommendation is to feed them peanut butter at about six months. And there’s a funny story for one reason why this has been changing—a British scientist was giving a presentation in Israel about the rise of peanut allergies. He asked the hundreds of attendees how many had seen a peanut allergy in the last year? And only, like, three people raised their hands—while nearly all pediatricians and allergists in the U.S. or the U.K. would have raised their hands. This might be why:

(BAMBA ADVERTISEMENT)

GRABER: Dad, mom, Bamba. Kids’ earliest words in Israel. Bamba is an Israeli treat that’s peanut butter flavored. Everyone loves it. Pretty much all Israeli babies eat it.

TWILLEY: And so now that British scientist is in charge of a major study, looking at whether exposing babies to peanut butter really early, like Israeli-style early—whether that will help their bodies learn that peanut protein is not something to freak out about. And his first set of results, from just a couple of years ago, show that exposing kids who were considered to be at a high risk for peanut allergy to peanut butter did seem to prevent the kids from developing an allergy.

SMITH: I think it’s important to note that whereas some people are in favor of that approach, not everyone is. And I think it’s still it still begs the question of why some people appear to be more susceptible to these allergies than others.

GRABER: So while it does seem as if introducing peanut butter earlier will help prevent a lot of people from developing peanut allergies, Matthew isn’t convinced that this will stop the incredible and surprising rise of peanut allergies all together. There’s still way too much we don’t understand.

SMITH: I think my inclination is that it isn’t going to be just one thing.

TWILLEY: For now, there are still plenty of kids for whom peanuts are deadly. But there are also lots of kids for whom peanuts are a lifesaver.

GRABER: Because they’re eating Plumpy’Nut.

MARTIN BLOEM: In principle it’s like peanut butter. It’s not much different as peanut butter.

TWILLEY: Martin Bloem is a senior nutrition advisor in the World Food Program. And he is talking about a food he uses in his aid work all the time: Plumpy’Nut.

BLOEM: When Andre Briend, he thought a lot about it, you know, what do children actually consume relatively easily.

GRABER: Andre Briend is a pediatrician in France. And he was trying to solve the problem of getting nutrients into kids who desperately needed them. At the time they had to go to a hospital if they were suffering from the kind of malnutrition that could kill them.

TWILLEY: Before Plumpy’Nut, the best treatment to get enough nutrients and calories into these kids quickly, to save their lives, was a product called F100, a therapeutic milk. And while F100 worked well, treating kids with it had some problems.

BLOEM: Milk can spoil very easily, so it’s really difficult to to keep those products. You have to keep it cool. We have to use fridges and in many places where we work it’s very difficult to use those fridges.

GRABER: This just wasn’t a good solution, it couldn’t help all the kids who needed it. But the Andre noticed a jar of Nutella. Which is delicious, but he also thought—hey, it has a great combination of proteins, energy, and fat!

TWILLEY: This is back in 1996. And Andre figures, why don’t I use the idea of Nutella and make a therapeutic nut paste for starving kids. The result was Plumpy’Nut, which is just peanut paste, vegetable oil, milk powder, sugar, vitamins and minerals. Peanuts, as we know, have a high protein content, they have a high fat content, so they have lots of calories and they’re also a great vehicle for all these nutrients. Plus they taste good.

BLOEM: You open it and you just squeeze it out. So it is it’s an incredible practical way to use it under the most difficult circumstances.

GRABER: And it works.

BLOEM: You give it for a couple of weeks and then kids recover extremely quickly on peanut butter. They do really, really well. It was the beginning of a revolution how we were treating and preventing acute malnutrition in a way which was not possible for the last forty, fifty years. Like, it was an enormous progress.

TWILLEY: And because it is so much easier to get it into communities that need it, Plumpy’Nut has helped Martin save many many more children’s lives.

BLOEM: They are so skinny, they’re sick. They have quite often diarrhea, you know, pneumonia sometimes. And so they can hardly take any food in. This is why it’s so incredible product because they can actually consume this product. We are already doing this for 12 years. And, you know, we serve about 80 million people including like about 20 percent children or so and so we talk about a lot of, lot of, lot of children. And this is just WFP. So UNICEF also must have millions of kids and then you have all the NGOs like MSF and—so I think it’s, yeah that’s what I said, it’s a revolution. It is many, many, many children have been saved because of this product.

GRABER: And it’s been so successful that they’ve used the formula to make new products. One is called Plumpy’Doz, and it’s to help prevent stunting. Stunting affects even more kids, and it’s kind of the precursor to the worst kind of malnutrition.

BLOEM: And that’s of course from a severity perspective maybe not as a big problem as the severe acute malnutrition. But the number of children who have stunted are so large that if you look at mortality impact the stunting has even more impact than the severe acute malnutrition.

TWILLEY: And Plumpy’Doz has made a huge difference there, too—it’s something that kids can squeeze into their mouths, they like the taste, and it has a shelf-life of two years. So it’s just super practical.

GRABER: But it’s not all rainbows and life-saving peanut butter pastes. Plumpy’Nut has inspired some controversies, too. People say it’s expensive—but it’s cheaper than the old product and you don’t have to have a hospital nearby.

TWILLEY: Then there’s the fact that Nutriset, the company that Andre Briend partnered with to make Plumpy’Nut, it took out a patent on the paste. And Nutriset enforced that pretty rigorously at first, to stop others from making it. Several NGOs criticised them heavily for that. But Martin thinks it was maybe necessary, especially in the early days.

GRABER: To make a life-saving product, the quality had to be extremely high. Of course. And it was new and nobody was quite sure it would work, so Nutriset wanted to really control the process to make sure each dose contained what it was supposed to contain.

TWILLEY: But, even beyond that, there’s a business model issue. Because Plumpy’Nut might be a miracle product in terms of saving lives, but it’s not exactly a high-volume product.

BLOEM: The problem of sustainability when you create products like this doesn’t work because severe acute malnutrition is relatively a phenomenon which doesn’t happen a lot among children. Like, you know, normally it’s very high prevalence if you talk about 3 percent of the children. So to make a sustainable business model is not very easy.

GRABER: But Martin and his colleagues have worked to create some businesses in which a life-saving peanut paste is made locally. One of these successes was in Rwanda, in partnership with the Clinton Foundation.

BLOEM: Which is a really cool program because they work with you know companies as well as with local companies with the government. And it’s a business model where we buy 25 percent of their produce for East Africa and they try to sell this 75 percent for the local market so that in fact a lot of the children from Rwanda can benefit from a good, high-quality product. Which is in principle a product I can get to my own grandchildren or children as such. And they use as the staple products from smallholder farmers who actually get, you know, they buy produce of there so you help the farmers on top of that.

TWILLEY: So this tiny little bean—the pea bean, as I still kind of want to call it—it seems like the most pedestrian food. I mean, lunchboxes, airlines snacks, it’s everywhere. But it turns out to be quite the super bean.

GRABER: It’s traveled all around the world and back. It’s been key in agriculture in the South in the U.S.. It’s helped save lives, and it’s also triggered medical mysteries. But I really wanted to leave you with perhaps the weirdest sandwich that it stars in, in Jon’s book-length ode to peanut butter.

TWILLEY: A sandwich that he is proud to say he created himself.

GRABER: Jon calls it the Simon and Garfunkel, because, of course, it contains parsley, sage, rosemary, and thyme. It’s a whole wheat bagel spread with peanut butter. Jon adds mozzarella cheese, a slice of tomato, sauteed spinach and mushrooms with a clove of garlic, a bunch of spices, and then he squeezes a slice of lemon on top.

(MUSIC)

TWILLEY: And that’s it for today’s show! Are you creamy or crunchy? Will you try Jon’s insane sandwich? Let us know, we love to hear from you. We have a couple of sponsors to thank this episode but first we want to thank Metcalfe’s Markets, a Wisconsin-based grocery store that kindly donated some of its fabulous cheese selection for our live show in Madison the other week.

(POST ROLL)

GRABER: Thanks this episode to Jori Lewis, Jon Krampner, Matthew Smith, Martin Bloem, and a special shout out to Owen Guo for helping us with our Mandarin pronunciation. And, of course, thanks to our long-suffering partners Geoff and Tim. Okay, I don’t think this one was much of a hardship assignment.

TWILLEY: There have been worse. We are back on August 1st, after a teeny tiny little break where we’ll be out reporting lots of new stories. Stay tuned, and stay in touch. All our deets are at gastropod dot com, along with links to all our guests’ books.