Pollen, peanuts, dust mites. These things aren’t poisonous – so why do some people’s bodies act like they are? In this episode, we’ll find out what happens during an allergic reaction and hear about new treatments.
This episode first appeared on July 28, 2016. Listen to the original here!
Allergy attack: How our bodies can overreact
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PRESENTER: You're listening to Brains On!, where we're serious about being curious.
PRESENTER: Brains On! Is supported in part by a grant from the National Science Foundation.
MOLLY BLOOM: Some of us are allergic to one thing.
PRESENTER: Like cats.
MOLLY BLOOM: Some of us are allergic to lots of things.
PRESENTER: Like cats and ragweed and dust mites and mold and peanuts and dogs and wheat and bees.
MOLLY BLOOM: Some of us aren't allergic to anything.
PRESENTER: What's that like?
MOLLY BLOOM: I wouldn't know. Anyway, today we're going to find out what causes allergic reactions and why only some people get them. And we'll find out how doctors treat allergies, and what new methods might be on the horizon. Keep listening.
You're listening to Brains On! from American Public Media. I'm Molly Bloom. And here with me today is 11-year-old Lily Backhouse from Lakewood, Colorado. Hi, Lily.
LILY BACKHOUSE: Hello, Molly.
MOLLY BLOOM: This episode was sparked by an email that Lily sent to us describing how her allergies were going crazy thanks to all the pollen in the air. So Lily, what does it feel like when you have those allergies? Is it in the spring or is it all the time?
LILY BACKHOUSE: It's usually just in the spring. My eyes get watery. And my nose gets stuffy.
MOLLY BLOOM: You sneeze a lot?
LILY BACKHOUSE: Well, not a lot, but I sneeze, sneeze occasionally.
MOLLY BLOOM: And do you have other allergies too?
LILY BACKHOUSE: I'm allergic to peanuts and tree nuts, and I grew out of a milk allergy.
MOLLY BLOOM: And what's the one thing you wish people without allergies understood about what it's like for you when you have allergies?
LILY BACKHOUSE: It's actually hard.
MOLLY BLOOM: Yeah, that's a hard question.
LILY BACKHOUSE: Well, I know it's kind of difficult not to be able to eat--
MOLLY BLOOM: Peanuts and nuts.
LILY BACKHOUSE: And if I do, I die.
MOLLY BLOOM: We don't want that to happen.
LILY BACKHOUSE: Without the risk of death while you're eating cake.
MOLLY BLOOM: So you have to be really careful about what you eat.
LILY BACKHOUSE: Yeah.
MOLLY BLOOM: So if someone is eating peanuts near you, it's not a problem, but you just can't eat it yourself.
LILY BACKHOUSE: Yeah. Or I can't rub my face on it.
MOLLY BLOOM: We don't want to do that. But later in the show, we're going to talk to an allergist who's going to tell us about some of the new treatments they're developing for peanut allergies. And I'm also allergic to a bunch of things. I'm allergic to dust mites and cats and mold and pollen and ragweed and a bunch of other things.
So I was also very curious to find out how and why we get allergies and it turns out that our listeners are also very interested. A lot of people sent in questions about allergies like Zachary.
ZACHARY: I'm wondering what causes allergies.
MOLLY BLOOM: Now, like a lot of topics we discuss on brains on some of the questions surrounding allergies are still a little bit of a mystery. We'll get to those in a minute. But first, we're going to start with something that scientists understand pretty well.
PRESENTER: What happens in your body when you have an allergic reaction?
MOLLY BLOOM: It all starts the very first time you encounter whatever it is you're going to be allergic to. Like, say, you breathe in some pollen.
PRESENTER: To your body, this pollen is a foreign substance and your body could react in different ways.
MOLLY BLOOM: Let's see what we have here, it could accept or tolerate the allergen invader. Sometimes using antibodies called immunoglobulin G or IgG for short to handle things.
PRESENTER: IgG is just ignore the allergen.
PRESENTER: OK. I'm here. Let's see. It's like plant dust or whatever who cares.
MOLLY BLOOM: Sometimes though, instead we will produce antibodies called immunoglobulin E or IgE.
PRESENTER: OK. I'm here. Let's see. Oh, no, it's pollen. Run! Oh!
PRESENTER: As you might have guessed, IgEs are the antibodies responsible for your allergy attacks.
PRESENTER: What are you doing just standing here it's pollen. Pollen!
MOLLY BLOOM: Of course, the first time your body encounters this pollen or any allergen really, you don't have much of a reaction. Instead, those IgEs will roam around the body until they come to rest on cells known as mast cells.
PRESENTER: OK. Calm down. I'll just take a seat here and--
ALLERGEN: Oh, hello there. You're kind of sitting on me.
LILY BECKHOUSE: Mast cells have special receptors that are a perfect fit for IgEs. That's why they love to pair up.
ALLERGEN: Do you mind if I just stay here? You're like really comfy. You know, it doesn't bother me. Be my guest.
LILY BECKHOUSE: Over time lots of these IgEs from that initial allergen end up on a mast cells, basically, just hanging out there causing no trouble.
ALLERGEN: So mast, do you watch that show, Game of Bones? It's about a skeletal kingdom, and it's the best. I love the characters. Except Lord Femur. He's so evil. Wanna here my theory?
LILY BECKHOUSE: Sure.
ALLERGEN: I think the meta carpels are going to team up with tibia and fibula to take on femur.
LILY BECKHOUSE: All is calm until the next time your body encounters the allergen.
ALLERGEN: Wait, is that? Oh, no. It's pollen.
LILY BECKHOUSE: Whoa, is that bad?
ALLERGEN: Yes, it's a worst thing ever. Ah!
LILY BECKHOUSE: OK, well then, ah! This time, the IgE is sitting on a mast cell with other IgEs, and when the allergen interacts with them, their reaction begins.
ALLERGEN: It's coming this way. It's touching me. Ah! Ah, what was that?
LILY BECKHOUSE: I kind of released some chemicals, but it's what they do.
MOLLY BLOOM: Mast cells are full of things like cytokines, proteases, and histamines. When the allergen, in this case pollen, connects with the IgE, it triggers a reaction in the mast cell that releases these things into your body.
ALLERGEN: I'm sure it's fine, right?
LILY BECKHOUSE: Well, these are pretty powerful chemicals.
ALLERGEN: Whatever. You did the right thing.
LILY BECKHOUSE: OK.
ALLERGEN: I mean, it was pollen. I'm on your--
LILY BECKHOUSE: So histamines from the mast cells that cause your body to feel out of whack.
MOLLY BLOOM: Histamines can make you itch, make your nose run, all that annoying stuff. In some cases, this reaction can even cause swelling of the throat.
ALLERGEN: I say we do this every time we see pollen.
LILY BECKHOUSE: Sure.
ALLERGEN: Show that stuff who's boss. I mean, it shouldn't be coming around here anyway.
LILY BECKHOUSE: Now, whether you're allergic to pollen or peanuts or mold or anything else, this is the way allergic reactions work.
MOLLY BLOOM: The reaction you get is different, depending on where and how the allergen got into your body.
LILY BECKHOUSE: Like through your nose--
MOLLY BLOOM: --or your digestive tract. We're going to talk more about these reactions and how to fight them in a little bit. But first, we want to answer another question.
HENRY: Hi. My name is Henry, and I'm from Denver, Colorado. My question is, why are some people allergic to things and some other people aren't?
MOLLY BLOOM: That's an excellent question, Henry. Now, Lily this is something you were also interested in too.
LILY BECKHOUSE: Right. So I spoke with Dr. Sarah Sheikh.
SARAH SHEIKH: I'm an allergist, immunologist, and rheumatologist. I work at the University of North Carolina.
LILY BECKHOUSE: Why aren't all people allergic to nuts or dogs or pollen and other allergens?
SARAH SHEIKH: So scientists and doctors are working really hard to figure out the answer to that question, as to why some people develop allergies and others don't. We don't have all the answers yet, but a good way to think about it is that even though each of us has two eyes, a nose, and a mouth, we all look different. Some of us have black hair, and others have blonde hair. Some people have blue eyes, and others have brown eyes in the same way everybody's body and immune system is different.
Your genes are what carry the information that's passed on to you from your parents and your family. We know that children that are born into families where allergies exist have a higher chance of developing allergies themselves. But in humans, if there were changes in genes that occur, these would take hundreds of years to translate into disease. So our genes alone can't really explain why there's an increase in allergy that we're seeing over the past few decades.
So that brings us to thinking about our environment. We know that many of our genes can be turned on and off by environmental factors. For example, if you get a viral infection, it can change the response of our immune system by turning some genes on and off, and this can increase the risk of allergies. And one theory about our changing environment is called the hygiene hypothesis. And this is interesting because it suggests that the immune system needs to come into contact with the germs and bacteria when we're babies in order for it to respond appropriately later in life.
We know also, that children who come into regular contact with farm animals have a lower incidence of allergy. And so the idea is that because we've now developed a cleaner, healthier lifestyle, which is more hygienic than ever, our bodies no longer need to fight germs as much as they did in the past. So perhaps, because of this, the immune system has shifted away from fighting infection to developing more allergies. But this is only one theory. The truth is, we still don't know the exact cause.
LILY BECKHOUSE: I was hearing a lot about genetics, and I know that genetics are usually something you can inherit from somebody, like your parents or grandparents, but I don't know anybody I am related to who has an allergy to any of the things I'm allergic to.
SARAH SHEIKH: That's an excellent observation, and that's exactly why genes may be a part of it, but it may be, essentially, how your environment plays into or interacts with those genes that actually determines at the end who develops an allergy or not. And by environment, I don't just mean the environment around us, it also speaks to the environment that you are exposed to. For example, as a child, did you get any infections, or what specific things happened in your environment that could be different than other people. So that's a really good observation, and that's why genes can't explain the entire picture.
We're going to hear more from Lily's conversation with Dr. Sheikh in just a bit. Right now, I'm sensing you're all itching to hear a mystery sound. Mystery sound. Here it is.
SUBJECT 1: One Mississippi, two Mississippi, three Mississippi.
MOLLY BLOOM: Any guesses?
LILY BECKHOUSE: Ah, somebody counting?
MOLLY BLOOM: Yes. And there was a little sound at the beginning of the mystery sound. Let's just hear that little sound one more time. Did you hear that?
LILY BECKHOUSE: Yeah.
MOLLY BLOOM: OK. Well, we're going to be back with the answer right after this. Do you have a mystery sound you'd like to share with us? A drawing of pollen? A question you want to hear answered on the show? You can send it to us at hello@brainson.org. And if you share your ideas with us, you'll get added to the Brain's Honor Roll. That's what Simon did when he sent us this question.
SIMON: My question is, what makes the colors of the sunset?
MOLLY BLOOM: Listen for an answer to that question during our Moment of Um and the latest group to join the Brain's Honor Roll, all at the end of the show. Keep listening.
You're listening to Brains On! from American Public Media.
LILY BECKHOUSE: I'm Lily Beckhouse.
MOLLY BLOOM: And I'm Molly Bloom.
LILY BECKHOUSE: You know, it's kind of ironic about your name.
MOLLY BLOOM: What do you mean?
LILY BECKHOUSE: You know, Molly Bloom, like a blooming flower giving off pollen, one of the things you are allergic to.
MOLLY BLOOM: I never thought about that. I'm glad I am not allergic to my name though. That would be kind of tough and awkward. I would sneeze every time I introduce myself. I'm Molly-- chew.
LILY BECKHOUSE: Well, those of us who have allergies know a thing or two about sneezing.
MOLLY BLOOM: But have you ever stopped to think about all the different kind of sneezes out there?
SUBJECT 2: A typical park on a sunny day. A light breeze, flowers in bloom, families, dogs, Frisbees, a beautiful scene. But for people with allergies, the scene is slightly uglier. It is a perfect storm of sneeze-inducing allergens. We're here today to catalog, capture, and commend the marvelous diversity of sneezes.
Now, we wait. Here comes a potential sneezer, handkerchief in hand. This signifies sneeze proximity.
SNEEZER 1: Chew-ah.
SUBJECT 2: Ah, the classic red-nosed exploder in its natural habitat. What else is in store?
SNEEZER 2: Ah-chew!
SUBJECT 2: Ah, The ever elusive squeaker. What's that over there?
SNEEZER 3: Ah, ah, ah-chew.
SUBJECT 2: And there goes the false starter. What a marvelous call it has. Ah, here comes a group, a family. Allergies run in families, so this could be a veritable cornucopia of sneezes.
SNEEZER 4: Ah, ah, ah, ah, chew!
SUBJECT 2: A super wind up.
SNEEZER 5: Ah chew-whew.
SUBJECT 2: Followed by a melody maker.
SNEEZER 6: Ah-chat.
SUBJECT 2: It capped off with a stealthy stinger. Oh, magnificent. What a show. Oh, wait a minute. Sh. Did you hear that? Me either. That was an elusive, silent sneezer. Very rare. And behind him, could it be--
SNEEZER 7: Choo. Choo. Choo. Choo. Choo.
SUBJECT 2: The chapter book, a personal favorite. Oh, the excitement and exhilaration of a sneeze in the wild. Happy, little explosions created by the noble nose. Thank you, you proud preposcus. We salute and cherish you. Goodbye, God bless, and Gesundheit.
MOLLY BLOOM: So Lily, how would you classify your own sneeze?
LILY BECKHOUSE: Ah, short and straight to the point. Ah-chew.
MOLLY BLOOM: I like it. I'm definitely, I think, the exploder. Do you have a favorite kind of sneeze?
LILY BECKHOUSE: Kitten sneezes.
MOLLY BLOOM: What's a kitten sneeze?
LILY BECKHOUSE: Like, kee.
MOLLY BLOOM: That is the cutest thing I ever heard. Well, if any of our listeners can think of other sneezes, we would love to hear those too. You could send us a recording of the sneeze and what you would name it at hello@brainson.org.
LILY BECKHOUSE: Sneezes are one way your body can react to an allergen.
MOLLY BLOOM: When you breathe in pollen, you're only getting a tiny bit of the protein you're allergic to, so the reaction isn't necessarily that severe.
LILY BECKHOUSE: But if you're allergic and you eat a peanut or get a bee sting,
MOLLY BLOOM: --you're getting a larger dose of that protein, and the effects can be more severe.
LILY BECKHOUSE: These severe reactions are called anaphylaxis.
MOLLY BLOOM: Dr. Joseph Hernandez, from Stanford, explained that anaphylaxis is when you have a reaction in more than one organ system at once.
JOSEPH HERNANDEZ: So it usually means that you have symptoms on your skin, so that's probably the most common thing that's involved. So breaking out in hives, itching; then also, respiratory symptoms, so coughing, shortness of breath, wheezing, an asthma attack; or problems with your gastrointestinal systems, so developing abdominal pain, vomiting, et cetera; or having changes in your circulatory system, low blood pressure, an increased heart rate, something like that.
MOLLY BLOOM: I know all of that sounds bad, and it is, but before you totally freak out, there's something I want you to hear. Let's get back to that mystery sound.
SUBJECT 1: One Mississippi, two Mississippi, three Mississippi.
MOLLY BLOOM: So any other guesses?
LILY BECKHOUSE: Ah, I think it's an EpiPen.
MOLLY BLOOM: Yes, it is an EpiPen. You got it. People who have serious allergies usually carry around an EpiPen with them in case they find themselves having an anaphylactic reaction. It looks like a big, fat pen, but inside, is a needle that delivers a shot of epinephrine.
JOSEPH HERNANDEZ: Basically, adrenaline. So the important things that it does during the anaphylaxis is that it can decrease some of the dilation of your blood vessels that happens. And so that will help people that have low blood pressure, as a result of anaphylaxis. It can help reopen your airways, and it decreases the leakiness of blood vessels that happens in anaphylaxis too, which can decrease a lot of the swelling and the hives, and even some of the swelling that may happen in your mouth and throat and things.
MOLLY BLOOM: This helps your body deal with the reaction until your body works the proteins out of your system. Lilly, do you have an EpiPen?
LILY BECKHOUSE: Yes.
MOLLY BLOOM: Have you ever had to use it?
LILY BECKHOUSE: No. That is my life goal to never have to use an EpiPen.
MOLLY BLOOM: That is an excellent goal, and you are not alone when it comes to having these severe allergies, like peanut allergies. In fact, they've become increasingly common in the United States. About 3 million people in the US have allergies to peanuts and tree nuts.
LILY BECKHOUSE: We've asked Dr. Sarah Sheikh why so many people are allergic to peanuts.
SARAH SHEIKH: So peanuts are among the eight food types that are referred to as the big eight. These are foods that cause over 90% of all food-related allergic reactions in the United States. The list of these foods are peanuts, tree nuts, milk, egg, wheat, soy, fish, and shellfish. All of these foods contain special proteins, specifically peanuts too, and the structure of these proteins is what stimulates a strong reaction by the immune system.
Now, these proteins are very stable, and they're resistant to heat, to enzymes, and also, resistant to food preparation and digestion. An important thing to remember is that if you have a peanut allergy, peanut in any and every form must be avoided because it can cause an allergic reaction. But the allergenicity of the peanut protein can be changed by various cooking methods.
For example, dry roasting peanuts at high temperatures can change the shape of the peanut protein, and this causes chemical changes in the protein, which makes it more allergenic compared to peanuts in the raw form. In Western countries, like the United States, where the way that peanuts are prepared is by dry roasting, the rate of peanut allergies on the rise, and if you look at countries like China, where predominantly, peanuts are either fried or boiled, they don't have that same increase in the rate of peanut allergies.
And there is thought as to maybe that could be one of the reasons why here, in Western countries, we're seeing that rise in peanut allergy. The truth is, nobody really knows for sure, but that's certainly, an observation that scientists and doctors have made. But again, if you have a peanut allergy, peanut in any form is to be avoided.
LILY BECKHOUSE: I can see what you mean because I've had things that are roasted in peanut oil and actually, without knowing it and had no reaction, even though I am allergic to peanuts.
SARAH SHEIKH: So that's also a really interesting observation about peanut oil. There are people who are allergic to peanuts who can safely consume foods that are made with highly-refined peanut oil because that peanut oil has been purified and then refined and then bleached and deodorize. And all of this removes the peanut protein from the oil, and that's why you may observe that even though you're allergic, you can tolerate that.
However, the unrefined peanut oil, which is also sometimes referred to as cold-pressed peanut oil or gourmet peanut oil still contains the peanut protein, and that needs to be avoided.
LILY BECKHOUSE: But treatments are being developed for peanut and food allergies?
SARAH SHEIKH: So the current treatments that are being developed are types of what we call immunotherapy. The idea with allergy shots is to take wheat or dust mite or whatever you may be allergic to, but to take tiny, microscopic amounts of that and prepare what we call immunotherapy for you. And this immunotherapy is unique to the person that's receiving it, and it involves building up tiny amounts of that into your body over time so that eventually your immune system is able to tolerate it. But this is only for symptoms of hay fever and for environmental allergies at this time.
The good news is that the first peanut powder treatments are currently now in big, clinical trials, or clinical studies, and it's not the same as taking a tiny bite out of a peanut, because one whole peanut contains a significant amount of peanut protein. So this is microscopic amounts that really, you wouldn't be able to do or even see with your eyes.
So this is something that has to be done in a very, very specialized experimental research setting with trained doctors, nurses, research staff available, because there's a really, really high risk of allergic reaction occurring. We are anticipating that in the next few years, depending on how these studies go and what results come from them, we might have something available, but that's probably still a few years from now. But again, it's a lot of progress from where we've come.
LILY BECKHOUSE: Thanks, Dr. Sheikh for talking with me today.
SARAH SHEIKH: Oh, of course. You're welcome.
MOLLY BLOOM: Allergic reactions happen when your body develops certain antibodies to proteins found in things like pollen or peanuts.
LILY BECKHOUSE: Scientists aren't 100% sure why allergies are so common, but they think it might be a combination of different factors, your genes and your environment.
MOLLY BLOOM: Many of our genes can be turned on or off by environmental factors, which change the response of our immune system and may increase the risk of developing allergies.
LILY BECKHOUSE: Scientists are working on developing immunotherapies to help fight these allergies, which can help make allergic reactions less severe or get rid of them altogether.
MOLLY BLOOM: That's it for this episode of Brains On!
LILY BECKHOUSE: Brains On! is produced by Marc Sanchez, Sanden Totten, and Molly Bloom.
MOLLY BLOOM: And we had production help from Emily Bright. Brains On! is supported in part by a grant from the National Science Foundation. Many thanks to Rachel Dunn, Dr. Mark Lachey, Dr. Amal Asad, Rob Holliday, John Zucco, Dave Fender, Maria Garcia Jorrit, Tony Pang, Nancy Col Martinez, Tracy Mumford, Nancy Yang, Eric Wrangham, and a big, fat Brains On! thanks to Jonathan Karl Martinez and Sophie Pang for doing the voices and bringing cells to life. High five, guys.
LILY BECKHOUSE: If you're a fan of Brains On! consider leaving a review in iTunes. It really helps other kids and parents find out about the show.
MOLLY BLOOM: And you can always keep up with us on Twitter and Instagram brains_on, and we're on Facebook too. Now, before we go, it's time for our moment of um-- um, um, um. um.
SIMON: Hi. My name is Simon. I'm from Montreal, Canada. My question is, what makes the colors of the sunset?
DEREK VELEZ: The sunsets have to do with both the light that's coming from the sun and the fact that it's passing through our atmosphere. So my name is Derek Velez, and I teach physics and astronomy at the high school level, at St. Paul's School in New Hampshire.
When we look up at the sky and we see the sun, we're seeing white light coming to us from the sun. And white light is really a combination of all the colors of light coming to us at the same time. But as the light passes through our atmosphere, the blue side of the light spectrum, the smaller wavelengths, bounce and get scattered by our atmosphere, so they get sent in all random directions.
So when we look off to the side, away from the sun, some of that blue light is getting scattered to us from that side. So that's why the sky looks blue during the day. However, as the sun is getting closer to setting, it starts to pass through more of our atmosphere, because it's at a lower angle. So because it's passing through more of our atmosphere, it has more time for that blue light to get deflected and scattered in all of the other directions.
So the only light that makes it to us, or most of the light that makes it to us, is red or orange or yellow or all the other colors other than blue. And so now, that part of the sky, closer to the sun at sunset and at sunrise, is going to look a lot more colorful, a lot redder.
MOLLY BLOOM: The sun is about to set on this episode, but not before I read the latest group of names to be added to the Brains Honor Roll. These are the kids who inspire each and every episode with the questions they send us. We consider all of you part of the Brains On! team.
Emma, from Jacksonville, Florida; Collette, from Costa Rica; Averie, from Glen Rock, New Jersey; Violet, from Portland, Oregon; Bodie, from Ventura, California; Naomi, from Santa Ana, California; Margot, from Lafayette, Colorado; Ainslie Annika and Kian, from Winchester, England; Zora Piper, from Berlin, Germany; Brock, from Boise, Idaho; Simone, from Syracuse, New York; Clover, from Oregon; Lucy, from Adelaide, Australia; Henry, from Brookline, Massachusetts; Cohen, from Bloomington, Minnesota; Oliver and Kara, from Minnetonka, Minnesota; Solomon, from Nevada; Edry, from Charlottesville, Virginia; Acacia, from Silver Spring, Maryland; Liam, from Ontario; Winston, Elliot, and Piper, from South Portland, Maine; Elias, from Durham, North Carolina; Julianna, from Woodbridge, New Jersey; Cooper and Mason, from Austin, Texas; Vesper, from Chandler, Arizona; Amel, from Portland, Oregon; Abigail, from Nashville; Caleb, Jack, and Lou, from North Branch, Minnesota; Mason, from Bartow, Florida; Ethan and Zoe, from Middlesex, New Jersey; Alexander, Miles, Julia, and Benjamin, from Lafayette, Colorado; Violet, from Saint Petersburg, Florida; Troy, from Charlotte, North Carolina; Felix, from Buffalo, New York; Jackson, from Fresno, California; Xander, from Amherst, New Hampshire; June, from Saint Paul; Molly and Sam from Newbury, Massachusetts; Ari, from Australia; George, from London; William, from Florida; Elizabeth, from Columbia, Maryland; and Petra, from Portland, Oregon.
We'll be back soon with more answers to your questions.
LILY BECKHOUSE: Thanks for listening.
[MUSIC PLAYING]
Ba, Ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On!
PRESENTER: Brains On! Is supported in part by a grant from the National Science Foundation.
MOLLY BLOOM: Some of us are allergic to one thing.
PRESENTER: Like cats.
MOLLY BLOOM: Some of us are allergic to lots of things.
PRESENTER: Like cats and ragweed and dust mites and mold and peanuts and dogs and wheat and bees.
MOLLY BLOOM: Some of us aren't allergic to anything.
PRESENTER: What's that like?
MOLLY BLOOM: I wouldn't know. Anyway, today we're going to find out what causes allergic reactions and why only some people get them. And we'll find out how doctors treat allergies, and what new methods might be on the horizon. Keep listening.
You're listening to Brains On! from American Public Media. I'm Molly Bloom. And here with me today is 11-year-old Lily Backhouse from Lakewood, Colorado. Hi, Lily.
LILY BACKHOUSE: Hello, Molly.
MOLLY BLOOM: This episode was sparked by an email that Lily sent to us describing how her allergies were going crazy thanks to all the pollen in the air. So Lily, what does it feel like when you have those allergies? Is it in the spring or is it all the time?
LILY BACKHOUSE: It's usually just in the spring. My eyes get watery. And my nose gets stuffy.
MOLLY BLOOM: You sneeze a lot?
LILY BACKHOUSE: Well, not a lot, but I sneeze, sneeze occasionally.
MOLLY BLOOM: And do you have other allergies too?
LILY BACKHOUSE: I'm allergic to peanuts and tree nuts, and I grew out of a milk allergy.
MOLLY BLOOM: And what's the one thing you wish people without allergies understood about what it's like for you when you have allergies?
LILY BACKHOUSE: It's actually hard.
MOLLY BLOOM: Yeah, that's a hard question.
LILY BACKHOUSE: Well, I know it's kind of difficult not to be able to eat--
MOLLY BLOOM: Peanuts and nuts.
LILY BACKHOUSE: And if I do, I die.
MOLLY BLOOM: We don't want that to happen.
LILY BACKHOUSE: Without the risk of death while you're eating cake.
MOLLY BLOOM: So you have to be really careful about what you eat.
LILY BACKHOUSE: Yeah.
MOLLY BLOOM: So if someone is eating peanuts near you, it's not a problem, but you just can't eat it yourself.
LILY BACKHOUSE: Yeah. Or I can't rub my face on it.
MOLLY BLOOM: We don't want to do that. But later in the show, we're going to talk to an allergist who's going to tell us about some of the new treatments they're developing for peanut allergies. And I'm also allergic to a bunch of things. I'm allergic to dust mites and cats and mold and pollen and ragweed and a bunch of other things.
So I was also very curious to find out how and why we get allergies and it turns out that our listeners are also very interested. A lot of people sent in questions about allergies like Zachary.
ZACHARY: I'm wondering what causes allergies.
MOLLY BLOOM: Now, like a lot of topics we discuss on brains on some of the questions surrounding allergies are still a little bit of a mystery. We'll get to those in a minute. But first, we're going to start with something that scientists understand pretty well.
PRESENTER: What happens in your body when you have an allergic reaction?
MOLLY BLOOM: It all starts the very first time you encounter whatever it is you're going to be allergic to. Like, say, you breathe in some pollen.
PRESENTER: To your body, this pollen is a foreign substance and your body could react in different ways.
MOLLY BLOOM: Let's see what we have here, it could accept or tolerate the allergen invader. Sometimes using antibodies called immunoglobulin G or IgG for short to handle things.
PRESENTER: IgG is just ignore the allergen.
PRESENTER: OK. I'm here. Let's see. It's like plant dust or whatever who cares.
MOLLY BLOOM: Sometimes though, instead we will produce antibodies called immunoglobulin E or IgE.
PRESENTER: OK. I'm here. Let's see. Oh, no, it's pollen. Run! Oh!
PRESENTER: As you might have guessed, IgEs are the antibodies responsible for your allergy attacks.
PRESENTER: What are you doing just standing here it's pollen. Pollen!
MOLLY BLOOM: Of course, the first time your body encounters this pollen or any allergen really, you don't have much of a reaction. Instead, those IgEs will roam around the body until they come to rest on cells known as mast cells.
PRESENTER: OK. Calm down. I'll just take a seat here and--
ALLERGEN: Oh, hello there. You're kind of sitting on me.
LILY BECKHOUSE: Mast cells have special receptors that are a perfect fit for IgEs. That's why they love to pair up.
ALLERGEN: Do you mind if I just stay here? You're like really comfy. You know, it doesn't bother me. Be my guest.
LILY BECKHOUSE: Over time lots of these IgEs from that initial allergen end up on a mast cells, basically, just hanging out there causing no trouble.
ALLERGEN: So mast, do you watch that show, Game of Bones? It's about a skeletal kingdom, and it's the best. I love the characters. Except Lord Femur. He's so evil. Wanna here my theory?
LILY BECKHOUSE: Sure.
ALLERGEN: I think the meta carpels are going to team up with tibia and fibula to take on femur.
LILY BECKHOUSE: All is calm until the next time your body encounters the allergen.
ALLERGEN: Wait, is that? Oh, no. It's pollen.
LILY BECKHOUSE: Whoa, is that bad?
ALLERGEN: Yes, it's a worst thing ever. Ah!
LILY BECKHOUSE: OK, well then, ah! This time, the IgE is sitting on a mast cell with other IgEs, and when the allergen interacts with them, their reaction begins.
ALLERGEN: It's coming this way. It's touching me. Ah! Ah, what was that?
LILY BECKHOUSE: I kind of released some chemicals, but it's what they do.
MOLLY BLOOM: Mast cells are full of things like cytokines, proteases, and histamines. When the allergen, in this case pollen, connects with the IgE, it triggers a reaction in the mast cell that releases these things into your body.
ALLERGEN: I'm sure it's fine, right?
LILY BECKHOUSE: Well, these are pretty powerful chemicals.
ALLERGEN: Whatever. You did the right thing.
LILY BECKHOUSE: OK.
ALLERGEN: I mean, it was pollen. I'm on your--
LILY BECKHOUSE: So histamines from the mast cells that cause your body to feel out of whack.
MOLLY BLOOM: Histamines can make you itch, make your nose run, all that annoying stuff. In some cases, this reaction can even cause swelling of the throat.
ALLERGEN: I say we do this every time we see pollen.
LILY BECKHOUSE: Sure.
ALLERGEN: Show that stuff who's boss. I mean, it shouldn't be coming around here anyway.
LILY BECKHOUSE: Now, whether you're allergic to pollen or peanuts or mold or anything else, this is the way allergic reactions work.
MOLLY BLOOM: The reaction you get is different, depending on where and how the allergen got into your body.
LILY BECKHOUSE: Like through your nose--
MOLLY BLOOM: --or your digestive tract. We're going to talk more about these reactions and how to fight them in a little bit. But first, we want to answer another question.
HENRY: Hi. My name is Henry, and I'm from Denver, Colorado. My question is, why are some people allergic to things and some other people aren't?
MOLLY BLOOM: That's an excellent question, Henry. Now, Lily this is something you were also interested in too.
LILY BECKHOUSE: Right. So I spoke with Dr. Sarah Sheikh.
SARAH SHEIKH: I'm an allergist, immunologist, and rheumatologist. I work at the University of North Carolina.
LILY BECKHOUSE: Why aren't all people allergic to nuts or dogs or pollen and other allergens?
SARAH SHEIKH: So scientists and doctors are working really hard to figure out the answer to that question, as to why some people develop allergies and others don't. We don't have all the answers yet, but a good way to think about it is that even though each of us has two eyes, a nose, and a mouth, we all look different. Some of us have black hair, and others have blonde hair. Some people have blue eyes, and others have brown eyes in the same way everybody's body and immune system is different.
Your genes are what carry the information that's passed on to you from your parents and your family. We know that children that are born into families where allergies exist have a higher chance of developing allergies themselves. But in humans, if there were changes in genes that occur, these would take hundreds of years to translate into disease. So our genes alone can't really explain why there's an increase in allergy that we're seeing over the past few decades.
So that brings us to thinking about our environment. We know that many of our genes can be turned on and off by environmental factors. For example, if you get a viral infection, it can change the response of our immune system by turning some genes on and off, and this can increase the risk of allergies. And one theory about our changing environment is called the hygiene hypothesis. And this is interesting because it suggests that the immune system needs to come into contact with the germs and bacteria when we're babies in order for it to respond appropriately later in life.
We know also, that children who come into regular contact with farm animals have a lower incidence of allergy. And so the idea is that because we've now developed a cleaner, healthier lifestyle, which is more hygienic than ever, our bodies no longer need to fight germs as much as they did in the past. So perhaps, because of this, the immune system has shifted away from fighting infection to developing more allergies. But this is only one theory. The truth is, we still don't know the exact cause.
LILY BECKHOUSE: I was hearing a lot about genetics, and I know that genetics are usually something you can inherit from somebody, like your parents or grandparents, but I don't know anybody I am related to who has an allergy to any of the things I'm allergic to.
SARAH SHEIKH: That's an excellent observation, and that's exactly why genes may be a part of it, but it may be, essentially, how your environment plays into or interacts with those genes that actually determines at the end who develops an allergy or not. And by environment, I don't just mean the environment around us, it also speaks to the environment that you are exposed to. For example, as a child, did you get any infections, or what specific things happened in your environment that could be different than other people. So that's a really good observation, and that's why genes can't explain the entire picture.
We're going to hear more from Lily's conversation with Dr. Sheikh in just a bit. Right now, I'm sensing you're all itching to hear a mystery sound. Mystery sound. Here it is.
SUBJECT 1: One Mississippi, two Mississippi, three Mississippi.
MOLLY BLOOM: Any guesses?
LILY BECKHOUSE: Ah, somebody counting?
MOLLY BLOOM: Yes. And there was a little sound at the beginning of the mystery sound. Let's just hear that little sound one more time. Did you hear that?
LILY BECKHOUSE: Yeah.
MOLLY BLOOM: OK. Well, we're going to be back with the answer right after this. Do you have a mystery sound you'd like to share with us? A drawing of pollen? A question you want to hear answered on the show? You can send it to us at hello@brainson.org. And if you share your ideas with us, you'll get added to the Brain's Honor Roll. That's what Simon did when he sent us this question.
SIMON: My question is, what makes the colors of the sunset?
MOLLY BLOOM: Listen for an answer to that question during our Moment of Um and the latest group to join the Brain's Honor Roll, all at the end of the show. Keep listening.
You're listening to Brains On! from American Public Media.
LILY BECKHOUSE: I'm Lily Beckhouse.
MOLLY BLOOM: And I'm Molly Bloom.
LILY BECKHOUSE: You know, it's kind of ironic about your name.
MOLLY BLOOM: What do you mean?
LILY BECKHOUSE: You know, Molly Bloom, like a blooming flower giving off pollen, one of the things you are allergic to.
MOLLY BLOOM: I never thought about that. I'm glad I am not allergic to my name though. That would be kind of tough and awkward. I would sneeze every time I introduce myself. I'm Molly-- chew.
LILY BECKHOUSE: Well, those of us who have allergies know a thing or two about sneezing.
MOLLY BLOOM: But have you ever stopped to think about all the different kind of sneezes out there?
SUBJECT 2: A typical park on a sunny day. A light breeze, flowers in bloom, families, dogs, Frisbees, a beautiful scene. But for people with allergies, the scene is slightly uglier. It is a perfect storm of sneeze-inducing allergens. We're here today to catalog, capture, and commend the marvelous diversity of sneezes.
Now, we wait. Here comes a potential sneezer, handkerchief in hand. This signifies sneeze proximity.
SNEEZER 1: Chew-ah.
SUBJECT 2: Ah, the classic red-nosed exploder in its natural habitat. What else is in store?
SNEEZER 2: Ah-chew!
SUBJECT 2: Ah, The ever elusive squeaker. What's that over there?
SNEEZER 3: Ah, ah, ah-chew.
SUBJECT 2: And there goes the false starter. What a marvelous call it has. Ah, here comes a group, a family. Allergies run in families, so this could be a veritable cornucopia of sneezes.
SNEEZER 4: Ah, ah, ah, ah, chew!
SUBJECT 2: A super wind up.
SNEEZER 5: Ah chew-whew.
SUBJECT 2: Followed by a melody maker.
SNEEZER 6: Ah-chat.
SUBJECT 2: It capped off with a stealthy stinger. Oh, magnificent. What a show. Oh, wait a minute. Sh. Did you hear that? Me either. That was an elusive, silent sneezer. Very rare. And behind him, could it be--
SNEEZER 7: Choo. Choo. Choo. Choo. Choo.
SUBJECT 2: The chapter book, a personal favorite. Oh, the excitement and exhilaration of a sneeze in the wild. Happy, little explosions created by the noble nose. Thank you, you proud preposcus. We salute and cherish you. Goodbye, God bless, and Gesundheit.
MOLLY BLOOM: So Lily, how would you classify your own sneeze?
LILY BECKHOUSE: Ah, short and straight to the point. Ah-chew.
MOLLY BLOOM: I like it. I'm definitely, I think, the exploder. Do you have a favorite kind of sneeze?
LILY BECKHOUSE: Kitten sneezes.
MOLLY BLOOM: What's a kitten sneeze?
LILY BECKHOUSE: Like, kee.
MOLLY BLOOM: That is the cutest thing I ever heard. Well, if any of our listeners can think of other sneezes, we would love to hear those too. You could send us a recording of the sneeze and what you would name it at hello@brainson.org.
LILY BECKHOUSE: Sneezes are one way your body can react to an allergen.
MOLLY BLOOM: When you breathe in pollen, you're only getting a tiny bit of the protein you're allergic to, so the reaction isn't necessarily that severe.
LILY BECKHOUSE: But if you're allergic and you eat a peanut or get a bee sting,
MOLLY BLOOM: --you're getting a larger dose of that protein, and the effects can be more severe.
LILY BECKHOUSE: These severe reactions are called anaphylaxis.
MOLLY BLOOM: Dr. Joseph Hernandez, from Stanford, explained that anaphylaxis is when you have a reaction in more than one organ system at once.
JOSEPH HERNANDEZ: So it usually means that you have symptoms on your skin, so that's probably the most common thing that's involved. So breaking out in hives, itching; then also, respiratory symptoms, so coughing, shortness of breath, wheezing, an asthma attack; or problems with your gastrointestinal systems, so developing abdominal pain, vomiting, et cetera; or having changes in your circulatory system, low blood pressure, an increased heart rate, something like that.
MOLLY BLOOM: I know all of that sounds bad, and it is, but before you totally freak out, there's something I want you to hear. Let's get back to that mystery sound.
SUBJECT 1: One Mississippi, two Mississippi, three Mississippi.
MOLLY BLOOM: So any other guesses?
LILY BECKHOUSE: Ah, I think it's an EpiPen.
MOLLY BLOOM: Yes, it is an EpiPen. You got it. People who have serious allergies usually carry around an EpiPen with them in case they find themselves having an anaphylactic reaction. It looks like a big, fat pen, but inside, is a needle that delivers a shot of epinephrine.
JOSEPH HERNANDEZ: Basically, adrenaline. So the important things that it does during the anaphylaxis is that it can decrease some of the dilation of your blood vessels that happens. And so that will help people that have low blood pressure, as a result of anaphylaxis. It can help reopen your airways, and it decreases the leakiness of blood vessels that happens in anaphylaxis too, which can decrease a lot of the swelling and the hives, and even some of the swelling that may happen in your mouth and throat and things.
MOLLY BLOOM: This helps your body deal with the reaction until your body works the proteins out of your system. Lilly, do you have an EpiPen?
LILY BECKHOUSE: Yes.
MOLLY BLOOM: Have you ever had to use it?
LILY BECKHOUSE: No. That is my life goal to never have to use an EpiPen.
MOLLY BLOOM: That is an excellent goal, and you are not alone when it comes to having these severe allergies, like peanut allergies. In fact, they've become increasingly common in the United States. About 3 million people in the US have allergies to peanuts and tree nuts.
LILY BECKHOUSE: We've asked Dr. Sarah Sheikh why so many people are allergic to peanuts.
SARAH SHEIKH: So peanuts are among the eight food types that are referred to as the big eight. These are foods that cause over 90% of all food-related allergic reactions in the United States. The list of these foods are peanuts, tree nuts, milk, egg, wheat, soy, fish, and shellfish. All of these foods contain special proteins, specifically peanuts too, and the structure of these proteins is what stimulates a strong reaction by the immune system.
Now, these proteins are very stable, and they're resistant to heat, to enzymes, and also, resistant to food preparation and digestion. An important thing to remember is that if you have a peanut allergy, peanut in any and every form must be avoided because it can cause an allergic reaction. But the allergenicity of the peanut protein can be changed by various cooking methods.
For example, dry roasting peanuts at high temperatures can change the shape of the peanut protein, and this causes chemical changes in the protein, which makes it more allergenic compared to peanuts in the raw form. In Western countries, like the United States, where the way that peanuts are prepared is by dry roasting, the rate of peanut allergies on the rise, and if you look at countries like China, where predominantly, peanuts are either fried or boiled, they don't have that same increase in the rate of peanut allergies.
And there is thought as to maybe that could be one of the reasons why here, in Western countries, we're seeing that rise in peanut allergy. The truth is, nobody really knows for sure, but that's certainly, an observation that scientists and doctors have made. But again, if you have a peanut allergy, peanut in any form is to be avoided.
LILY BECKHOUSE: I can see what you mean because I've had things that are roasted in peanut oil and actually, without knowing it and had no reaction, even though I am allergic to peanuts.
SARAH SHEIKH: So that's also a really interesting observation about peanut oil. There are people who are allergic to peanuts who can safely consume foods that are made with highly-refined peanut oil because that peanut oil has been purified and then refined and then bleached and deodorize. And all of this removes the peanut protein from the oil, and that's why you may observe that even though you're allergic, you can tolerate that.
However, the unrefined peanut oil, which is also sometimes referred to as cold-pressed peanut oil or gourmet peanut oil still contains the peanut protein, and that needs to be avoided.
LILY BECKHOUSE: But treatments are being developed for peanut and food allergies?
SARAH SHEIKH: So the current treatments that are being developed are types of what we call immunotherapy. The idea with allergy shots is to take wheat or dust mite or whatever you may be allergic to, but to take tiny, microscopic amounts of that and prepare what we call immunotherapy for you. And this immunotherapy is unique to the person that's receiving it, and it involves building up tiny amounts of that into your body over time so that eventually your immune system is able to tolerate it. But this is only for symptoms of hay fever and for environmental allergies at this time.
The good news is that the first peanut powder treatments are currently now in big, clinical trials, or clinical studies, and it's not the same as taking a tiny bite out of a peanut, because one whole peanut contains a significant amount of peanut protein. So this is microscopic amounts that really, you wouldn't be able to do or even see with your eyes.
So this is something that has to be done in a very, very specialized experimental research setting with trained doctors, nurses, research staff available, because there's a really, really high risk of allergic reaction occurring. We are anticipating that in the next few years, depending on how these studies go and what results come from them, we might have something available, but that's probably still a few years from now. But again, it's a lot of progress from where we've come.
LILY BECKHOUSE: Thanks, Dr. Sheikh for talking with me today.
SARAH SHEIKH: Oh, of course. You're welcome.
MOLLY BLOOM: Allergic reactions happen when your body develops certain antibodies to proteins found in things like pollen or peanuts.
LILY BECKHOUSE: Scientists aren't 100% sure why allergies are so common, but they think it might be a combination of different factors, your genes and your environment.
MOLLY BLOOM: Many of our genes can be turned on or off by environmental factors, which change the response of our immune system and may increase the risk of developing allergies.
LILY BECKHOUSE: Scientists are working on developing immunotherapies to help fight these allergies, which can help make allergic reactions less severe or get rid of them altogether.
MOLLY BLOOM: That's it for this episode of Brains On!
LILY BECKHOUSE: Brains On! is produced by Marc Sanchez, Sanden Totten, and Molly Bloom.
MOLLY BLOOM: And we had production help from Emily Bright. Brains On! is supported in part by a grant from the National Science Foundation. Many thanks to Rachel Dunn, Dr. Mark Lachey, Dr. Amal Asad, Rob Holliday, John Zucco, Dave Fender, Maria Garcia Jorrit, Tony Pang, Nancy Col Martinez, Tracy Mumford, Nancy Yang, Eric Wrangham, and a big, fat Brains On! thanks to Jonathan Karl Martinez and Sophie Pang for doing the voices and bringing cells to life. High five, guys.
LILY BECKHOUSE: If you're a fan of Brains On! consider leaving a review in iTunes. It really helps other kids and parents find out about the show.
MOLLY BLOOM: And you can always keep up with us on Twitter and Instagram brains_on, and we're on Facebook too. Now, before we go, it's time for our moment of um-- um, um, um. um.
SIMON: Hi. My name is Simon. I'm from Montreal, Canada. My question is, what makes the colors of the sunset?
DEREK VELEZ: The sunsets have to do with both the light that's coming from the sun and the fact that it's passing through our atmosphere. So my name is Derek Velez, and I teach physics and astronomy at the high school level, at St. Paul's School in New Hampshire.
When we look up at the sky and we see the sun, we're seeing white light coming to us from the sun. And white light is really a combination of all the colors of light coming to us at the same time. But as the light passes through our atmosphere, the blue side of the light spectrum, the smaller wavelengths, bounce and get scattered by our atmosphere, so they get sent in all random directions.
So when we look off to the side, away from the sun, some of that blue light is getting scattered to us from that side. So that's why the sky looks blue during the day. However, as the sun is getting closer to setting, it starts to pass through more of our atmosphere, because it's at a lower angle. So because it's passing through more of our atmosphere, it has more time for that blue light to get deflected and scattered in all of the other directions.
So the only light that makes it to us, or most of the light that makes it to us, is red or orange or yellow or all the other colors other than blue. And so now, that part of the sky, closer to the sun at sunset and at sunrise, is going to look a lot more colorful, a lot redder.
MOLLY BLOOM: The sun is about to set on this episode, but not before I read the latest group of names to be added to the Brains Honor Roll. These are the kids who inspire each and every episode with the questions they send us. We consider all of you part of the Brains On! team.
Emma, from Jacksonville, Florida; Collette, from Costa Rica; Averie, from Glen Rock, New Jersey; Violet, from Portland, Oregon; Bodie, from Ventura, California; Naomi, from Santa Ana, California; Margot, from Lafayette, Colorado; Ainslie Annika and Kian, from Winchester, England; Zora Piper, from Berlin, Germany; Brock, from Boise, Idaho; Simone, from Syracuse, New York; Clover, from Oregon; Lucy, from Adelaide, Australia; Henry, from Brookline, Massachusetts; Cohen, from Bloomington, Minnesota; Oliver and Kara, from Minnetonka, Minnesota; Solomon, from Nevada; Edry, from Charlottesville, Virginia; Acacia, from Silver Spring, Maryland; Liam, from Ontario; Winston, Elliot, and Piper, from South Portland, Maine; Elias, from Durham, North Carolina; Julianna, from Woodbridge, New Jersey; Cooper and Mason, from Austin, Texas; Vesper, from Chandler, Arizona; Amel, from Portland, Oregon; Abigail, from Nashville; Caleb, Jack, and Lou, from North Branch, Minnesota; Mason, from Bartow, Florida; Ethan and Zoe, from Middlesex, New Jersey; Alexander, Miles, Julia, and Benjamin, from Lafayette, Colorado; Violet, from Saint Petersburg, Florida; Troy, from Charlotte, North Carolina; Felix, from Buffalo, New York; Jackson, from Fresno, California; Xander, from Amherst, New Hampshire; June, from Saint Paul; Molly and Sam from Newbury, Massachusetts; Ari, from Australia; George, from London; William, from Florida; Elizabeth, from Columbia, Maryland; and Petra, from Portland, Oregon.
We'll be back soon with more answers to your questions.
LILY BECKHOUSE: Thanks for listening.
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Ba, Ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On!
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