Do I really have a food allergy? (Transcript)

Body Stuff with Dr. Jen Gunter

Wednesday, June 15, 2022

Dr. Jen Gunter:
When we decided to make an episode about food allergies, one of the producers for Body Stuff, Camille, told me about a story from her childhood. She was 4 years old, and she LOVED going to the grocery store.

[00:00:15] Camille Petersen:
Well, first there's the fruit and vegetable section, where there are a lot of colors and different shapes and smells, and there's just kind of a lot going on. And then you have like the misting of the vegetables. Which is obviously really cool. It feels like you're in a rainforest or jungle.

[00:00:35] Dr. Jen Gunter:
And she’d always point out new foods to try… she was an adventurous eater. But one day, her parents took her to the doctor for eczema, a skin condition. And the doctor gave her an allergy test.

[00:00:51] Camille Petersen:
We came out of that appointment with like a long list of things I was allergic to.

[00:00:57] Dr. Jen Gunter:
All these foods that Camille couldn’t have any more… But it wasn’t until she went back to the grocery store that she realized what that list really meant.

[00:01:08] Camille Petersen:
So like we're in the fruit and vegetables section, and I remember pointing to grapes and being like “can we get those?” And she's like, no. And I'm like, why not? She's like, you're allergic to grapes. And then the next thing was apples. She was like, you're allergic to those too. And then oranges. She told me I was allergic to those.

[00:01:33] Dr. Jen Gunter:
The grocery store got way less fun. A few months go by and poor little Camille isn’t eating oranges. Or grapes. Or apples. And she thinks – that’s it, I’ll never have any of these delicious foods again.

[00:01:49] Camille Petersen:
So my grandma was a pediatrician and, she probably offered me grapes or like an apple. And I was like, oh, I can't have those things anymore because I'm allergic. And she was suspicious of that. So she had a bunch of epi pens and like, obviously as a doctor. And so she kind of just like started giving me the things I was allegedly allergic to. Like when I was with her. And I didn't react to anything and I didn't have any allergic reactions. And eventually she just reported back to my parents that like, Camille does not have allergies to these things.

[00:02:34] Dr. Jen Gunter:
Almost all of the food allergies that Camille thought she had…She actually didn’t have! So she went back to eating all the fruits she loved.

[00:02:44] Camille Petersen:
I remember feeling like really excited that I could drink orange juice again.

[00:02:50] Dr. Jen Gunter:
So.. what happened? Camille’s experience of mistaken food allergies is actually more common than you might think. There’s so much confusion about food allergies, and these days, social media can make it seem like they’re silently lurking everywhere, causing a whole host of health problems…

I’m Dr. Jen Gunter and From the TED Audio Collective – this is Body Stuff.

This episode, we’ll explain how food allergies actually work, the difference between an allergy and an intolerance, and why knowing the difference really matters when it comes to our health.

Plus… what went wrong with Camille’s allergy test, and how you can avoid making the same mistake.

All this, after the break.


[00:04:06] Dr. Jen Gunter:
Dr. Ruchi Gupta is a pediatrician and an allergist. But it wasn’t until she had kids that she experienced food allergy in her personal life. It happened on a normal afternoon - her son and daughter were playing together.

Dr. Ruchi Gupta:
He was eating a peanut butter and jelly sandwich and he had these sticky fingers and, you know, kids they're slapping each other. And he must have touched her mouth. And then all I remember is them yelling and him yelling for me. And I ran over and she was covered in hives. And it started spreading down her neck and body. And then you're thinking, okay, what do I do now? I didn't have an epinephrine auto injector cause I studied food allergy, but I didn't have it in my family. Um, I have Benadryl, so you know, I grabbed the Benadryl, I gave her some Benadryl and being a pediatrician, it's always do I go to the emergency room? Is she getting better? Or can I manage her at home? you know? So, these are all like questions that I then realized as I'd been talking to so many parents trying to understand the experience of having a child with food allergy that every parent goes through.

[00:05:04] Dr. Jen Gunter:
Can you just give us a general explanation about what an allergy actually is?

[00:05:10] Dr. Ruchi Gupta:
It's an immune mediated reaction. Your immune system is rejecting this food, your immune system saying, okay, we got an invader and we got to get it out.

[00:05:20] Dr. Jen Gunter:
Food allergies are an IMMUNE response. The immune system is designed to protect us from dangerous invaders. Like viruses, bacteria, and parasites. But with food allergies, there is a glitch in the immune system, and it mistakes a PROTEIN in food for one of these invaders. So when one of those proteins enters the body of someone who’s allergic, the immune system mounts a response. The food protein isn’t harmful per se, but your body treats it like it is. It sends out a flood of antibodies… the same kind of defenders the immune system uses to fight off other biological threats.

[00:06:00] Dr. Ruchi Gupta:
And so it, leads to this cascade, um, in your body immediately with tons of, you know, chemicals being released

[00:06:09] Dr. Jen Gunter:
The antibodies bind to a special type of white blood cell called mast cells, and tell them to release chemical messengers called histamines. They do all kinds of important things for us, but with an allergic reaction, there’s an abnormal release of histamines. And they cause most allergy symptoms.

[00:06:30] Dr. Ruchi Gupta:
And that reaction for food allergy can be anything from skin, which we talked about, hives, itching, redness, swelling, uh, to tightening of the throat, to trouble breathing your respiratory tract, GI, vomiting, um, and even cardiovascular, a drop in blood pressure and fainting, and it can rapidly happen and it can be life-threatening and it has been, and those are the stories you hear about, and that's why it causes so much fear.

[00:06:58] Dr. Jen Gunter:
In the US, allergic reactions to food land about 200,000 people in the emergency room each year. And almost all of these severe allergy attacks are caused by a pretty small list of foods.

[00:07:12] Dr. Ruchi Gupta:
So peanuts, tree nuts, milk, egg, soy, wheat, shellfish, finfish, and Sesame.

[00:07:20] Dr. Jen Gunter:
So our immune systems are obviously designed to protect us a threat detection, repair. So how does an, a food allergy happen?

[00:07:28] Dr. Ruchi Gupta:
That is such a good question. Um, and this is actually an area of a lot of research right now. There's one theory where, uh, in babies, you know, with severe eczema, they tend to be highest risk of developing a food allergy. And the theory behind that is, uh, if you have broken skin, uh, and food proteins get in through your skin, your immune system views it as an invader. Now, if your body sees that food for the first time through the gut, so if you eat it first and it goes into your gut, it's safe.

[00:08:03] Dr. Jen Gunter:
So, if you're thinking about a food protein, we are built to basically explore it with our guts first. And so if we start exploring it in other ways then our immune systems, like, wait a minute, what the heck is this?

[00:08:19] Dr. Ruchi Gupta:
That is one of the leading theories. Exactly.

[00:08:23] Dr. Jen Gunter:
Studies have shown that kids can develop peanut allergies through broken skin, and this might be true for other foods as well. But food allergies can also show up in adults. Dr. Gupta says there are a few things that can trigger them, like moving to a new place…

[00:08:40] Dr. Ruchi Gupta:
A lot of adults move locations, uh, and something around the environment triggers the turn on, switch for them, their, a food allergy to get started.

[00:08:50] Dr. Jen Gunter:
Another possible trigger could be developing an illness.

[00:08:54] Dr. Ruchi Gupta:
So they developed some kind of a bacterial or viral infection, which was the turn on switch for their allergy.

[00:09:00] Dr. Jen Gunter:
And hormonal changes can bring them on, too.

[00:09:03] Dr. Ruchi Gupta:
So puberty and then pregnancy, and then menopause. You know, we do see more food allergies developing. Um, at those different time points.

[00:09:14] Dr. Ruchi Gupta:
One of my favorite comics is an adult talking to a kid saying when I was your age, there were no food allergies, because we all think that, you know, when we were kids, there were no bans and you'd take peanut butter and jelly to school every day. Right? And so there's this generational confusion and divide where they're like, this can't be real. This didn't exist.

[00:09:31] Dr. Jen Gunter:
Food allergies have always been around. But it’s true that in the last few decades, there’s been a big increase. So.. what happened? Well, no one really knows, but scientists are doing a lot of research to try to figure it out.

[00:09:49] Dr. Ruchi Gupta:
Like, how have our diets changed in a couple of generations, we used to eat locally grown foods from our area and how it's changed and expanded to foods coming from all over the world.

[00:10:00] Dr. Jen Gunter:
We sort of co-evolved with our food you know, we did an episode last year and we talked about the dramatically different diets, you know, regionally around the world and, you know, so that takes you know, generations and generations and millennia, and you've sort of developed this relationship with this food, but now I can fly to another country and be exposed to a food that I could never have been exposed to, you know, 400 years ago.

Dr. Ruchi Gupta:

[00:10:31] Dr. Jen Gunter:
Another common explanation is known as the hygiene hypothesis. Our lives are a lot cleaner these days. We come into contact with fewer germs, and parasites, than we used to. So our immune system doesn’t get educated on pathogens and it isn’t as preoccupied with these threats. Basically, it's bored and looking for something to do. There’s a lot we still don’t know about food allergies. Dr. Gupta says that the science is still evolving, and it's confusing... and this can lead people to think they have an allergy when they actually have something else… A food intolerance. What's the difference? Well, a different thing is happening in the body. Allergic reactions are caused by the immune system, while intolerances are all about the digestive system. But since food allergies and intolerances are both related to food and some of the symptoms can overlap, it can sometimes be hard to tell the difference. Milk is a great example. Some people are allergic to milk. Other people are intolerant of it, which means…

[00:11:39] Dr. Ruchi Gupta:
You're missing the enzyme to convert the lactose. So, um, because you're missing that enzyme, you're going to get, you know, discomfort and bloating and diarrhea potentially. And um, those type of symptoms, as opposed to a milk allergy where you would get, you know, the symptoms we discussed.

[00:11:57] Dr. Jen Gunter:
So with a milk allergy, it would be an allergy to the protein in the milk. And then with obviously lactose intolerance, it's an inability to digest one of the sugars.

[00:12:06] Dr. Ruchi Gupta:
You got it. Exactly.

[00:12:10] Dr. Jen Gunter:
Food intolerances can be caused by a lot of different things. So with lactose intolerance, it’s not having enough of a particular enzyme in your small intestine. Other intolerances can be caused by irritable bowel syndrome. And sometimes your body just doesn’t like a specific food.

Dr. Gupta says that the best way to tell the difference is just to pay attention to your symptoms.

If you have a food allergy, you’ll probably get symptoms like: hives, itching, or swelling. If you have a food intolerance, you’ll likely have digestive issues. An upset stomach, bloating. Or even diarrhea. And the biggest difference… is time. Allergic reactions almost always happen really quickly.

[00:12:56] Dr. Ruchi Gupta:
Most of the time it happens immediately. You'll start feeling symptoms and it'll it'll start going right away in the first 30 minutes.

[00:13:03] Dr. Jen Gunter:
I think that's a really important point because I see people all the time and they're all worried about what they had yesterday and sort of what it's made them feel today.

[00:13:13] Dr. Ruchi Gupta:
That's right. That's right. Absolutely.

[00:13:15] Dr. Jen Gunter:
I see a lot of people who spend a lot of money on expensive allergy testing. And they show up with this big list of foods that they're supposedly allergic to. And this workup was usually done because of, you know, non-specific symptoms or symptoms that to my ear, anyway, don't sound like an allergy. They're not talking about hives or rash or oral swelling. They're talking about maybe fatigue or bloating, which are real symptoms and due to real medical conditions.

So what would you say to someone thinking about, you know, embarking on this testing?

[00:13:47] Dr. Ruchi Gupta:
I would say, go see an allergist, you know, go see your primary care doctor, you know, your pediatrician, your internist, your family medicine doctor first who will take your symptoms and then decide where you should go, right.

[00:14:02] Dr. Jen Gunter:
We hear so much about food allergies these days, that it’s easy to wonder: do I have one too? And a lot of people take allergy tests to find out… but on their own, these tests aren’t that helpful; if a blood test comes back positive, that doesn’t necessarily mean you will have an allergic reaction to that food.

[00:14:23] Dr. Ruchi Gupta:
That's why you don't do testing unless you have symptoms. So if somebody comes in, you listen to the symptoms that they have with a specific food, and then you test, right? To that specific food. And then if the symptoms and the tests are both matching, you confirm that it's a food allergy

[00:14:46] Dr. Jen Gunter:
Remember Camille’s false allergy tests? That’s where her doctor went wrong – by ordering tests, even though Camille wasn’t demonstrating any reactions to specific foods. But there’s one, surefire test that food allergists still use all the time.

[00:15:04] Dr. Ruchi Gupta:
So the gold standard for testing for food allergies is pretty simple. It's called an oral food challenge. And all that means is you sit in a room and eat the food. And if you have a reaction, you have a positive food allergy.

[00:15:16] Dr. Jen Gunter:
You might have noticed ads for at-home tests for food allergies and sensitivities. And Dr Gupta says these tests are way less accurate than the tests a doctor will use… she says to never EVER rely on one of those at-home tests for a diagnosis. I’ve even seen predatory marketing suggesting that any illness could actually just be a food allergy… and that misconception can end up doing a lot of harm… people might not get the care they need for real illnesses, or they might be severely restricting their diets.

[00:15:50] Dr. Ruchi Gupta:
I've heard a lot of people say, oh, I took five foods out and I feel better, but you know, again, there's a placebo effect and then there's, you know, which one was it. And maybe we can narrow that down. So you're not taking five, 10 foods out of your diet. So many people are taking foods out of their diet unnecessarily, And it's not easy to live life without certain foods in your diet.

[00:16:14] Dr. Jen Gunter:
Before you eliminate a food, it’s important to ask: WHY? Taste, religion, culture, environmental concerns… these are all valid reasons why someone might avoid certain foods. But for undiagnosed, chronic health problems, complex food removal can sometimes lead to unhealthy food restrictions, and create unnecessary anxiety! If you do have uncomfortable reactions to a food, it’s important to know whether it’s caused by an intolerance or an allergy or celiac disease…. Because the treatments and the health implications can be very different!

So, skip instagram and TikTok, see a real health care provider if you’re having symptoms, so you can get an actual diagnosis and get on the right path to feeling better.

After the break… What can Richard III, Sigmund Freud, and AC/DC teach us about the history of food allergies?

Plus, some exciting new developments in how we prevent and treat them.


[00:17:23] Dr. Matthew Smith:
King Richard, the third, um, was allergic to strawberries. Or, had a reaction to strawberries. And so he used it to his political advantage. He, there is a, a rival that he wanted to get rid of. And so he, uh, surreptitiously ate some strawberries. Uh, when I think this guy was feeding him a meal or something like that, and then he accused him of witchcraft and had him executed.

[00:17:48] Dr. Jen Gunter:
King Richard the third. He's the one who locked the boys in the tower, right?

[00:17:53] Dr. Matthew Smith:
Yes, yeah. I'm pretty sure that's the one.

[00:17:56] Dr. Jen Gunter:
Dr. Matthew Smith is a food allergy historian.

[00:18:01] Dr. Matthew Smith:
So historians often dislike doing so-called retrospective diagnosis. So we don't like calling something an allergy before there was the word allergy. There are discussions of, uh, what sounds like food allergy going all the way back to, uh, the ancient Greeks, so someone eating cheese, for example, and, uh, it being described as being very, very healthy for some people. And then other people come off badly and we interpret that come off badly as having some kind of reaction to it.

[00:18:36] Dr. Jen Gunter:
Reactions that might have been food allergies are mentioned as far back as the time of Hippocrates. But it wasn’t until 1906 that we even had the term allergy.

[00:18:48] Dr. Matthew Smith:
So “allergy” is coined by a Viennese pediatrician, Clemons Von Pirquet in 1906. And, um, what he found, uh, inoculating children against the various, uh, infectious diseases at the time is that a certain number of children would react badly.

[00:19:07] Dr. Jen Gunter:
Von Pirquet noticed that some children would have side effects that looked similar to the kinds of bad reactions to food. Remember, allergies are an immune response. So, what Von Pirquet was really noticing was the immune system in action. But his definition wasn’t very specific – he considered basically ANY reaction an allergy.

And those early allergists were even less clear about treatments.

[00:19:07] Dr. Matthew Smith:
And so around about the 1930s and forties, um, which is really the heyday of Freudian psychoanalysis, there was increasing interest in the relationship between psyche and soma, the mind and the body. Rather than saying that something outside the body is causing these symptoms, they said it's all in the mind. And so something in your social or emotional environment is problematic. And often this was family situations, so you get this very, very strange term emerging, the parent-ectomy, meaning that the only way you're going to heal your child is get the child out of the home. It was very influential and it's really indicative of how, how powerful psycho psychoanalytical ideas were during the mid 20th century. Now, what's interesting about this before we totally dismiss a lot of this. There is clearly a connection between what's going on in terms of stress, um, including mental stress, to the severity of those sorts of reactions.

[00:20:45] Dr. Jen Gunter:
Yeah. I mean, I, I mean, I think it also speaks to sort of our complete, obviously lack of understanding of the mind body connection. I mean, as somebody who has Eczema, and only developed it later in life. Yeah. I can absolutely tell you that, you know, stress clearly makes it worse. But it is fascinating to sort of, you know, whenever I start getting itchy, I'm like, okay, I must be stressed, what’s going on, you know? So.. how do we get from food allergies being treated as a purely psychological problem, to where we are now? From food allergies as a bizarre oddity to a pressing public health issue? Dr. Smith says the turning point happened in the 1980s. And it was all… because… of the peanut.

[00:21:27] Dr. Matthew Smith:
What happens is that starting in the late 1980s, early 1990s, there's an increasing number of people, primarily children and young adults who, uh, have serious peanut allergies and, and an increasing number of fatalities.
You can't mess about with peanut allergy. Like there's no, there's no BS with peanut allergy, a serious peanut allergy, you know what causes it, you know, it's serious and you know what you need to do to avoid it.

[00:21:59] Dr. Jen Gunter:
We don’t really know why there was an increase in peanut allergies. But we do know that it became a very serious health issue, very quickly. Dr. Smith says he’s combed through years of scientific literature and hasn’t been able to find cases of deadly peanut allergies before the 1980s…

[00:22:16] Dr. Matthew Smith:
I've combed through allergy literature very carefully. And I have not come across a case of fatal peanut allergy in the medical literature prior to I think around 1987. Before then there are other cases of fatal food allergies to egg, to seafood, to other things. But peanuts are just not mentioned.

[00:22:42] Dr. Jen Gunter:
Again, there are a few theories about why food allergies have increased… like our rapidly changing diets, and our reduced exposure to bacteria and parasites.

But the shift seemed to happen almost overnight. Peanuts went from a staple in every school, to something that could be deadly… A lot of people had trouble adjusting.

Dr. Smith remembers going to the big stadium where he grew up, in Edmonton, Alberta.

[00:23:09] Dr. Matthew Smith:
I remember going to these games and they would sell bags of peanuts, like one pound bags of peanuts in the shell. And you would just go through the whole bag during the course of the game and just chuck the shells onto the floor. Right. And so literally when you would leave the stadium, you'd just be shuffling through peanut shells and they kind of create this bit of a dust, uh, at your feet.

[00:23:34] Dr. Jen Gunter:
These days, we know that just being around peanut shells in that environment is really unlikely to cause a serious allergic reaction.

But back then, we didn’t. And there was one kid with a peanut allergy who just really wanted to be able to go to the football games… so his mom wrote a letter to the stadium management.

[00:23:52] Dr. Matthew Smith:
And said. you know, Could you do something about this? And, they, they, they banned the peanuts.

For the first few years there wasn't really any reaction to the ban. Uh, the football fans didn't seem to mind. Um, but then ACDC, the big rock band came.

On the list of prohibited items, so you had: no guns, no drugs, no knives, no booze, uh, no fireworks, no peanuts.

[00:24:22] Dr. Jen Gunter:
But the new peanut ban started a big controversy in Edmonton, and a whole lot of ACDC fans wrote passionate letters to the local paper.

[00:24:32] Dr. Matthew Smith:
So some people, were saying, you know, this is absolutely necessary. I don't want, to, I don't want to die because someone's eating peanuts. and, then other people are saying, this is a complete bogus, and you're ruining my concert. So yeah, you had this real schism within the ACDC fans on the issue of whether peanuts should be brought in or not. Cause I mean, who eats peanuts at an ACDC concert anyways, I guess,

[00:25:00] Dr. Jen Gunter:
Things eventually settled down. And the Edmonton stadium still doesn’t sell peanuts, but no one’s writing angry letters about it anymore. And there’s some good news on the peanut allergy front! For decades, parents were told not to feed peanuts to their babies. The idea was to wait until the immune system was more mature before introducing them.

[00:25:21] Dr. Ruchi Gupta:
In the year 2000, the American academy of pediatrics said, oh, no, I don't know what's going on. We should not be feeding peanuts to babies.

[00:25:28] Dr. Jen Gunter:
But now the guidelines are changing…

[00:25:31] Dr. Ruchi Gupta:
And we found that actually introducing early, prevents. And then it flipped again. And now the recommendation is to introduce peanut products early to babies.

[00:25:40] Dr. Jen Gunter:
And it’s not just allergy prevention that has improved. If your child has a peanut allergy, there’s even a possible treatment!

[00:25:48] Dr. Ruchi Gupta:
Now, um, there is the first approved oral immunotherapy, uh, treatmentfor peanut allergy. Uh, it is, it's pretty much, you know, peanut protein powder and you slowly increase it over time. And then you develop tolerance, not complete tolerance, but kind of desensitization. Um, and you can tolerate up to a certain amount.

[00:26:11] Dr. Jen Gunter:
If you’ve been scared that a peanut could kill you, being able to tolerate exposure is a big deal! And there’s good news, too, for people with egg or milk allergies.

[00:26:22] Dr. Ruchi Gupta:
If you bake egg and milk, what we found is that at least half of people with an egg or milk allergy can tolerate baked egg and milk because it denatures the protein when you bake it for a certain amount of time and a certain temperature. And so what's exciting about that is if you do have a milk or egg allergy, you should do a bake challenge or talk to your allergist about a bake challenge, because if you can eat it baked, two things happen. One, you get to enjoy all that good food and two, you, uh, have a higher chance of growing out of it completely. So if you have a food allergy, it doesn't have to be, for life.

[00:27:00] Dr. Jen Gunter:
So what, uh, what advice do you give your patients on how to live with a food allergy and still have a healthy relationship with eating?

[00:27:06] Dr. Ruchi Gupta:
Yeah, that's so important. So many people have this fear and stress, um, as did I, and my daughter, and we still do, um, it's, it's challenging, really challenging to avoid a food. I think what we have learned and what we try to do is help families, you know, live as normal of a life as they can, right? That is the take home: know what's happening in your body, know what you have, know how to manage it and know if there's treatments for it. Cause a lot of these things have treatments. Don't live your life, avoiding foods. You don't have to, you know? And if you have to know what you need to do in case you eat it, right?

[00:27:49] Dr. Jen Gunter:
So, if you feel unwell, and someone tells you it’s a food allergy?

[00:27:53] Dr. Ruchi Gupta:
Get it diagnosed, know what you have and then work to manage and treat it, you know, in the best way possible.

[00:27:59] Dr. Jen Gunter:
And see a board certified allergist.

Dr. Ruchi Gupta:
(laughter) The end.

[00:28:14] Dr. Jen Gunter:
Next time, on Body Stuff: we’re tackling vaccine misinformation.

So you’re kind of tracking two outbreaks, right? The actual pathogen and the way in which it's presented either in media or in, uh, even in journals.

Dr. Jen Gunter:
We’re gonna talk about vaccine development, vaccine testing…and getting better at communicating about all of it.

Body Stuff is brought to you by the TED Audio Collective. It’s hosted and developed by me, Dr. Jen Gunter. The show is produced by TED with Transmitter Media. Our team includes Camille Petersen, Poncie Rutsch, Gretta Cohn, Michelle Quint, Banban Cheng, Sammy Case and Roxanne Hai Lash. Phoebe Wang is our sound designer and mix engineer. This episode was written and produced by Mitchell Johnson and edited by Sara Nics. Fact checking by the TED fact checking team.

We’re back next week with more Body Stuff. Make sure you’re following Body Stuff in your favorite podcast app so you get every episode delivered straight to your device. And leave us a review! We love hearing from our listeners.

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