Science Friday
Hosted by Flora Lichtman and Ira Flatow
Food allergies are on the rise. For kids with less severe peanut allergies, one potential treatment could be found in the grocery aisle.
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This is Science Friday. I'm Flora Lichtman, here with Ira Flatow. Today in the podcast, why is the peanut the bad seed of allergens? And more on the science of food allergies. If you are sending kids to school with a lunch every day, like I am, you probably have noticed that food allergies seem to be more common today than they used to be. Lots of foods are banned from schools for safety. Certain iconic sandwiches are peanut butter non grata. I thought for sure you'd laugh at that, Ira.
It's a good one.
You probably also know parents navigating food allergies with their kids, sort of anxiously giving their babies teeny tiny tastes of eggs and nut butters, standing by with a bottle of Benadryl in hand. But what does the science say? Are food allergies more common than they were a few decades ago? And if so, why? And how well do we actually understand why certain foods trigger certain reactions in certain people? We want to hear from you. What questions are you itching to Get answered about food allergies. Are you curious why the humble peanut is such a bad seed when it comes to allergies? Give us a call. Our number is 877-925-9174. Now to answer your questions and ours is Dr.
Scott Citra, Director of the Jaffe Food Allergy Institute at Mount Sinai Hospital in New York. Welcome back to Science Friday.
Thank you. Great to be here.
So are food allergies on the rise?
So I think that's a definite yes. We did a study back in 1997 when we looked across the United States to see the rate of peanut allergy in children. It was 1 in 250. We repeated that study five years later. It doubled to 1 in 125. And a few years after that, in 2011, it was up to 1 in 70. I couldn't believe it myself. And I was like, there must be something wrong with our study. But just around that same time, there were studies coming out of the US and other locations, in Canada, in Australia, all with this greater than 1% with peanut allergy.
Why?
Well, that's the, I don't know, billion-dollar question. But there are a lot of different hypotheses. And the biggest one is really about what we say is the hygiene hypothesis, or the microbiome, the communities of germs that live in and on us. And the reason that that is part of it is, why do allergies happen? It's our immune system, the part of our body that fights infection for us, or watches against cancer developing. So that's the same part that ends up making an attack on the foods, or for that matter, pollen, or cat dander, and things like that, and allergy. And that part of the immune system had a job. But as we now live in a place where we're not living on farms, the food that we eat
is kind of clean, like what I have for breakfast could sit in the cupboard for like a year without going bad because there's no bacteria. Our dishwashers clean our dishes. It's been seen that as industrialization happens in locations, the rates of allergy increase because our immune system's looking to be in balance and ends up getting out of balance and fighting things it doesn't need to fight.
Are you saying that food allergies are my immune system having a hobby?
Maybe if you were living in a parasitized jungle, you would be someone who's prone to allergy, might have been someone who did great in that environment. But now, living in the clean environment, you may be more prone to mount an attack on otherwise innocent things that you're eating or exposed to.
What is the difference between an intolerance? You know, we hear a lot about gluten. How is that different from what we're talking about with allergies?
So the word allergy is applied to the immune system having a response against the food in this case, whereas an intolerance is more of a metabolic issue. And by that, the most common example is lactose intolerance. Actually, most of the world's population doesn't have much of an enzyme that breaks down the sugar in milk. And if you don't have that enzyme, or you lose it with age, you have trouble digesting milk, you end up with bloating and gas and loose stools and such. But it's not a life-threatening thing. The word, sometimes people will say gluten intolerance for celiac disease, but that's a very different illness.
I want to geek out a little bit with you. And to get into this question, I want to invoke one of my favorite all-time episodes of television. It's really an ode to the food allergy. It's the finale of Broad City's first season where Alana, who has a shellfish allergy, is pushing her limits at a fancy seafood restaurant.
Abby, I am a veteran of this game. I got three to three and a half servings of shellfish left in me. I feel it. And then my throat's gonna start to close up, and you'll just stab me with an EpiPen. It's not a big deal.
Okay, Scott, here's my question. What is it about fish with a shell that sets off so many people's immune system that causes this allergy?
So there's a much deeper scenario in this because I could rephrase this issue as what kinds of allergies do we see in adults? And the more serious allergies that we see in adults may be for shellfish, for example. And the potential reason why are probably two. One is that foods that you don't eat as frequently might be ones that in between eating them, your immune system might get ready like, well, where is this? I'm ready to attack it, instead of having a continuous exposure to it. So nuts and seafood, shellfish like that, fall into that category. There is also the possibility that there are proteins in the environment that are similar. So for example, dust mites, cockroach, these actually have proteins that are similar
to the shellfish proteins. And it may be that not eating it, being exposed to these in the environment, might also hype up something that can lead to more of a reaction to it. And that might be why shellfish is one of the more common allergens in adults.
My jaw is dropping because it's related to a cockroach? A shellfish?
Well, some people say cockroach of the sea, but I didn't say that.
Let's go to the phones. Taffy in St. Paul, Minnesota. Are you with us?
Hi.
Hi. Go ahead.
Hi. I have always had allergies and I noticed before I went through menopause that my allergies would flare up when I was premenstrual or during, you know, during that part of my cycle. And so I'm wondering if hormones have anything to do with allergies?
Yeah, so if, again, we're talking about food allergies, there are a lot of things that could happen to our body in a moment in time that could make you more sensitive. So one possibility can be that menstruation cycle could be part of what would make you more reactive at some times rather than others. The other things that can do that for some people are exercise. So maybe you could eat something like wheat. Without exercise, you're fine, but with exercise, you end up with a reaction to it, probably because it gets into the bloodstream differently. Alcohol makes food go into the bloodstream more quickly, so that could make a reaction worse. A viral illness could make a reaction worse. And actually, even aspirin medications could make it worse because probably it also makes the protein go into the bloodstream more quickly without being digested. So these are all little variations that affect either the immune system
or digestion that could make reactions more prominent.
Is microdosing peanuts a way to stave off a food allergy?
So you've changed topics to one that I was hoping that we could talk about at least some.
You're welcome.
So thank you for that. So the very exciting thing is that both prevention strategies and treatment strategies have emerged in the last few years that have really changed the landscape of food allergy. And it's extremely exciting. And so with regard to what you were speaking of, that microdosing word is what we refer to as oral immunotherapy.
You don't use the word microdosing?
Well, we do with patients, yes. But the idea there is that you're allergic to it, but maybe we could start with giving a very small amount and then gradually get the immune system to look at it. This is not something to try at home, obviously, and it has risks and benefits. But it can, for many people, alter the immune response. They can at least be what we would call bite safe, meaning that maybe you could get someone up to some amount of, in the example you gave peanut, but we could look at other foods. So there's actually an FDA-approved version for peanut allergy, and physicians, allergists, will use other foods in that realm as well. And then, another really big change has been that, for the first time, there's a medication, a biologic medication, called omelizumab or the brand Imazolar, which is an injected
medication that can raise threshold, making people bite safe as well. And so that really is quite new, and something to ask your allergist about if you haven't spoken about therapeutics before.
And is it just that you're teaching the immune system to kind of get used to this?
In the case of the treatment that you mentioned, the microdosing of the food, yes, you're trying to make the immune system gradually accept it more as something that is okay for you. But you do, for most people, become dependent on using that food like a medicine, and staying on that food at some rate to stay in balance, not to be allergic to it. And in the prevention side of the story, these types of discoveries also said, well, gee, babies are getting these higher rates of food allergy. What if you could get the food to them earlier? And it used to be like, don't give peanut until you're three years old, but many years ago, it was noticed that was probably not the right advice. And now, the recommendations are, especially for babies who are prone to allergy, for
having eczema or similar, that they should get introduced to infant safe forms of peanut early, and other food, and other allergens as well. And that could reduce the risk by 80% for some children.
Yes, I lived this, where we were like, you know, just dedicated to giving peanut butter, you know, on the regular. Let's try James in Winchester.
Hello?
Go ahead, James, go ahead with your question.
Oh, hello. Yes, I'm in Winchester, Kentucky, and I'm about to open a health science museum relating to hydrogen gas as a multifaceted therapy. And among the research papers, it seems to indicate that hydrogen gas inhalation is good for allergies, and I'm wondering, is there any science on that for food allergies?
I am not aware of any science on that, sorry.
Let's stay with the phones. Let's go to Diane in Portland, Oregon. Diane?
Hi, go ahead.
Hi, I have become allergic to things in the pea family. I have eaten them all my life and now at 57 I have to have an EpiPen. And, and you know how they put pea protein in things now. So I've always, I have other allergies. So I've been careful about them, but I, I'm just wondering about becoming allergic to something that you've eaten all your life. You know, when you're talking about the microdosing.
No, so, um, again, don't try that at home. Talk to an allergist in terms of microdosing. But you bring up a really interesting thing, which is that, um, people can be allergic to almost anything and legumes, I mean peanut is a bean. Uh, and yet, most people with a peanut allergy don't react to other beans. But if you are allergic to beans, there are ones that are more potent, like green pea, chickpea, lentil, and then ones that are less potent, like black beans, white beans. And you see these kinds of variations for people. And then the fancy food industry has put pea protein, um, concentrated pea protein in a lot of foods, which has resulted in people realizing that suddenly they're having an allergic reaction to some, uh, meat substitute hamburger or to some yogurt that's, uh, been enriched with pea protein.
And they were okay eating peas and carrots. They hadn't maybe had pea soup for a while, but this higher concentration of pea in these foods set them off and they realized, wait, I have an allergy. And there are people who have severe reactions to those more concentrated forms, including soy, they might be able to eat edamame, but soy protein isolate, which is concentrated, they react to. So it's a fascinating, I mean, that's why I love what I do. It's really fascinating how you can dissect this and it's like a Sherlock Holmes thing. But yeah, you, you should definitely talk to your allergist about the different nuances related to this more uncommon allergy that you have.
Don't go away more on this when we come back.
That's sort of the holy grail of food allergies, trying to get rid of it completely.
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I have a question because when I was a teenager, I was allergic to everything just about. I had a skin test where they put like 100 different things on my arm. And so which one blew up? Are they still doing that now?
Well, I mean, for better or worse, yes, we still do that, but not 100 things.
I mean, that was bananas, peanuts. If I, I wouldn't have eaten anything.
So advice, advice to your listeners is that a good allergist wouldn't just do like 100 tests randomly. You really need to talk to, you know, talk to the doctor about what's bothered you or not, and have them select exactly what should be tested. But yes, the skin test, the blood tests are still done. The blood tests have become more advanced. And so they are more helpful than they were years ago. They're, we're able to define the allergy better now than we were before. But sometimes all of those tests, they're not like a yes, no pregnancy test. And sometimes we have to do a test called a feeding test to see if a person's really allergic to it, under supervision with an allergist.
Scott, what are the unsolved mysteries? Like the great mysteries of food allergies?
Oh my, well, we would love to have a cure. Can you completely stop this from happening? And the, you know, all of the therapies that most people are aware of still depend on some kind of ongoing treatment. It's not very common to just say, okay, I could stop doing anything. And now I'm just never allergic to that food again. We're doing a study now that's an interesting one where we're looking at two medications. One that's been approved for eczema, otherwise known as atopic dermatitis, itchy skin rash, which quells allergic response, and adding a second medicine that essentially knocks out the cells that are making the antibodies in your body that make these allergies happen, hoping that if we could use them together, maybe we could get closer to a cure.
But that's sort of the holy grail of, of food allergies, trying to get rid of it completely.
You know, we've, we've seen so many amazing advances with immunotherapy for illnesses, like for cancer, teaching the immune system to recognize something. Can you teach the immune system not to recognize something?
Well, in this case, that's a fantastic question. Most of the therapies that we're looking at are trying to teach the immune system to look Look at it in a different way, so to still see it. And actually, when you, when anyone with that food allergy eats the food, their immune system does see it, and you do get antibodies to the food that are not a problem. The IgE antibodies is the name of the ones that cause a problem. The IgG ones, G for good, E for evil, are the ones that are helpful. And we're trying to usually get the immune system to treat the food in a more helpful kind of way, not completely ignore it.
Not ignore it, yeah. I mean, you've been in this, in this field for decades. Aside from introducing foods early, are there other ways in which the way that we think about allergies has changed over time?
Yeah, I mean, aside from calling me out as elderly, I would say that-
I did not.
So I would say that, oh, my gosh, like, when I started, we were telling people, you're allergic, don't eat the food, there's nothing else we could do, here's your epinephrine, and you're on your way. And now I'm having, you know, very long conversations with each family, which is fantastic, about ways of trying to get the food into the diet, about ways to prevent another allergy from happening, about, you know, safe ways to use therapies to really make things safer in general for the person who has the food allergy, so that they don't have to worry about each bite, and living in a landmine where anything that could be a problem.
What is the biggest misconception we have about food allergies?
I think it really is about the food allergy versus intolerance. You know, someone might say, oh, I'm allergic to that because it gives me gas, or something along those lines, whereas someone with a, with a real allergy may have a life-threatening problem, or at least it's keeping them from eating the food. There are mild allergies. Some people have just an itchy mouth from various fruits and vegetables that are raw. But the ones who have these potentially life-threatening ones really have to be careful and carry medications, and that's another important message. Talk to your doctor about having self-injectable or administrable epinephrine. There's now a nasal spray version of epinephrine, which is just new on the market. So if you haven't heard about that, and if you're concerned about using epinephrine, it's safe. It's the same medicine that was used before.
They had asthma medicines that we have today, like, hey, doc, my asthma, here's your injection of epinephrine. Thanks, doc, you're the best. It's a very safe and effective medicine, and it saves lives.
Thank you, Scott.
Thank you.
Thanks for being with us. Scott Citra is the Director of the Jaffe Food Allergy Institute at Mount Sinai Hospital in New York.
And that is about all we have time for. Lots of folks helped make this show happen, including... Kory Zoguchi.
Sandy Roberts. Robin Casmer.
Jordan Smudjic. I'm Flora Lichtman. Thanks for listening.
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