What Causes Food Allergies in Kids ? | Dr. Amna Husain

Food allergies have been on the rise, but what causes these allergies in kids? In this video, board certified pediatrician and food allergy mom Dr. Amna Husain discusses what causes food allergies in kids .

Transcription

Dr. Amna Husain:
Is it just me, or are more kids coming down with food allergies? It's not just you. Food allergies are increasing in prevalence. And today, that's exactly what we're going to talk about. It's Food Allergy Awareness Week.

Dr. Amna Husain:
I'm Dr. Amna Husain, Board-Certified Pediatrician, Board-Certified Lactation Consultant, and mom; in fact, food allergy mom. My daughter has food allergies. And not just food allergies, she has tons of seasonal allergies as well; which is a whole nother headache altogether. I've seen her be miserable, I've seen her rub her eyes, I've seen her with the whole allergic salute and everything. However, food allergies, that takes really that whole misery of allergies to another level because it adds in a whole nother component of parental anxiety.

Dr. Amna Husain:
So today we're going to talk about food allergies, why they happen, and what we can possibly do to prevent them. Because, as you know, I am pregnant with baby number two. I want to do what I can to possibly prevent this baby having food allergies. All right. So stay tuned and find out how.

Dr. Amna Husain:
So, as I mentioned earlier, food allergies are definitely increasing in prevalence. In fact, they doubled over the last generation. About two children in every classroom are affected by food allergies. That's a lot of kids. And don't forget, food allergies can develop at any time, even adulthood, which is really important to think about. So we have to consider: why do food allergies happen?

Dr. Amna Husain:
Well, there's a couple of different aspects here. Allergies are complex and they're multifactorial, including food allergies. There's a genetic component, for sure. So if you have a family history of an allergic disease, like eczema, allergic rhinitis, asthma, you're in a higher likelihood of likely developing food allergies. It can also increase your baby's risk of developing food allergies.

Dr. Amna Husain:
So, for example, I have eczema and a little bit of allergic rhinitis, or hay fever, and probably have begun to develop some asthma as I've gotten older. My husband, while he doesn't have many seasonal allergies, does have quite a few drug allergies, or allergies to medications. And sometimes lifestyle and environment plays a factor too.

Dr. Amna Husain:
Research shows that 66%, or two out of three children who have a food allergy, have a parent who don't have any. My daughter would fall within that. So, for example, my parents are immigrants. And they came to this country in 1980. They have no allergic symptoms, no family history of allergies or atopy. And then, out of all my siblings... we're four girls, total... two of us have eczema and two of us have asthma. As I've mentioned, I've gone on to develop hay fever and some degree of asthma myself. And now, the next generation, my daughter has food allergies. So as you can see, there's a genetic, environmental and lifestyle component factor here.

Dr. Amna Husain:
So then how does an allergy to a food actually develop? I think we're all familiar with allergies to pollen or ragweed, maybe even some drug allergies, but we're not exactly sure how the food allergy develops. It's kind of the same concept, in many ways. Food allergies develop when your body mistakenly identifies a food, or a substance, as a threat or harmful. The immune system releases an antibody known as IgE, which then goes on to trigger a cascade of symptoms, and different cells and cell signaling factors, which basically give you all those symptoms.

Dr. Amna Husain:
Now, if it's an environmental allergen, perhaps it's just watery eyes, runny nose, itchy throat. And when I say just, trust me, as I mentioned, my daughter has really terrible allergies so I know it can be very miserable. I'm on allergy shots because they're so miserable for me. So I completely understand that this is not a small component.

Dr. Amna Husain:
However, with a food allergy, the risk is anaphylaxis, which is much serious and much more life threatening. So anaphylaxis is actually going to be a bigger system involvement. Typically, there's at least two systems involved. It could be the skin, it could be the cardiovascular system, your respiratory system, your GI system. So there's multiple systems that could be involved.

Dr. Amna Husain:
And that's what makes it so scary, your throat potentially closing, hives, vomiting, blood pressure dropping. Those are the scary symptoms that we often hear about when we're concerned about potentially anaphylaxis. And that's why it's so important to educate families on how food allergies can develop and what we can do to prevent them. And if they do develop, how we can treat potentially a life threatening emergency, like anaphylaxis, in the moment.

Dr. Amna Husain:
Now, this video isn't just about anaphylaxis. We were talking about why food allergies develop. We mentioned they're complex and multifactorial: lifestyle, environment, the immune system, it all plays a role. But diet diversity from the very beginning, when your child's first beginning solids, can have a tremendous impact.

Dr. Amna Husain:
Now, I've mentioned this briefly before on my video on starting solids for baby. And if you haven't seen that, I highly recommend checking it out. I'll link it right here. But diet diversity is so important, not only just to let your child explore new tastes, flavors, nutrients, textures, but really getting that gut used to different types of potentially allergenic foods.

Dr. Amna Husain:
So about 60% to 70% of the immune system can live within the child's gut. And we want to really prime that immune system so it sees the food early on before potentially seeing it later and considering it a threat. And if you wait too long to introduce the food, you run the risk of the immune system basically seeing that potential food, or that food source or food substance, as harmful.

Dr. Amna Husain:
So, let me explain. The lymphatic tissue that breaks down and recognizes food antigens in the body can see the food early on and recognize it as a friend. But if you see it a little later, you've given that immune system time to mature, it might actually start to recognize it as a harmful substance. That, again, can depend on genetics, lifestyle, environment. So you want to potentially try to introduce these allergenic foods really early on so that your child's body can start to really see these foods as not harmful, but again, friends.

Dr. Amna Husain:
Not only is it important, what we put in our bodies, but what we don't expose our bodies to. And I'm talking about the hygiene hypothesis here. I'm a firm believer in the hygiene hypothesis. And if you're not familiar with it, it supports the concept that we need exposure to the right type of bacteria to really support a healthy immune system.

Dr. Amna Husain:
Now, COVID has been terrible for this. But basically think of urbanized living, indoor living, hand sanitizing, lots of exposure to antibiotics, for example, that we have seen in the past couple of years and decades. That all of that, over time, has really decreased our exposure to good bacteria. And potentially, that good bacteria can help support an immune function so that we're not necessarily attacking other substances, like potential food allergens, as harmful.

Dr. Amna Husain:
So what does that mean? Get outside, try to get your child outdoors, let them play, let them play in the dirt, let them play in the mud. Of course, all these things in moderation. And yes, I 100% understand that COVID has been terrible for this. But it's really an important concept to think about and be aware of.

Dr. Amna Husain:
Another really important thing to think about is vitamin D. So, actually, studies have shown that individuals who live closer to the equator and have good exposure to sunlight are actually at a lower risk of developing food allergies. And those who live further away from the equator are at higher likelihood of developing food allergies.

Dr. Amna Husain:
Now, of course, everything in moderation. This does not mean you go outside and sunbathe or have your child sunbathe, that's not what I'm talking about at all. But data has shown that having healthy, good vitamin D levels, can potentially decrease the likelihood of developing food allergies later on.

Dr. Amna Husain:
So one thing you have to remember, are peanuts are not the only allergens out there, there's so many other allergenic foods. Just to name a few, tree nuts, shellfish, fish, soy, sesame, wheat, dairy, eggs, the list goes on and on. But that's about most of the foods that make up about 90% of the food allergies that we see.

Dr. Amna Husain:
Now, some of the allergies, your child might actually be able to outgrow. For example, cows milk, wheat and eggs are allergies that we often see fade or improve as a child grows in age. However, peanuts, tree nuts, even shellfish, those are allergies that typically stay with you even into adulthood. And amongst children who have food allergies, about 40% have allergies to more than one type of food. My daughter falls within that category. And children with food allergies are about two to four times more likely to have other allergic diseases, like asthma or hay fever. Again, these are things that we do see.

Dr. Amna Husain:
So then what can we do to potentially prevent food allergies from developing? Well, we've already mentioned diet diversity and introducing these foods very early on, hopefully within the four to six month timeframe. This is all data backed up, by not only the NIH, but the USDA and the American Academy of Pediatrics. Introducing highly allergen food early on can definitely decrease the likelihood of your child developing food allergies. And there's so many products out on the market that can help you do that, as a parent. Because I know it can be really overwhelming to try to introduce peanuts, cashews, almonds, shrimp, eggs, all of these things, when you have a little baby just starting solids.

Dr. Amna Husain:
So there's tons of products out on the market. I highly encourage you to talk to your pediatrician about your child's personal atopic profile, their health history, and how to go about introducing these highly allergenic foods for them.

Dr. Amna Husain:
So if we know that early introduction is good for us, and we know that diet diversity is good for us, and we see that food allergies are rising, then why do these myths continue to persist? Well, some of them begin in pregnancy. So I'm pregnant right now with baby number two. And even when I was pregnant with my first, I ate everything, all the nuts, I ate seafood. Of course, high mercury fish, we tried to be careful around. But that wasn't the time that I basically cut out nuts from my diet, or peanut butter from my diet, or eggs from my diet. No, instead you should actually try to make sure you're getting diet diversity as a pregnant woman as well.

Dr. Amna Husain:
When we start solids for baby, I think there's been a lot of other concepts too out there. Always start with maybe rice cereal, or maybe trying not to feed your baby X, Y, Z, until they reach a certain age. Well, you don't really have to worry about cutting out certain foods or not feeding your baby certain foods, unless it's honey. And we typically wait to introduce honey until 12 months of age for the botulinum risk. But otherwise, the other foods, you can absolutely start introducing them at four to six months of age.

Dr. Amna Husain:
Of course, you have to think about your child's developmental readiness, safety profiles, gagging, choking, becoming comfortable, with whichever method you choose to start introducing solids. But then you absolutely should be thinking, each step of the way, about introducing these potentially highly allergenic foods early on. Because studies do show that if a parent delays introduction, after even 12 months of age, the risks of sensitizing and developing a food allergy do increase.

Dr. Amna Husain:
So, again, I've already mentioned that, for example, my daughter has food allergies, we do have the genetic profile there. We did do early introduction with my daughter, but there's a few things I would definitely do different. And in this pregnancy I'm continuing to do diet diversity. I'm going to talk to our allergist as well, about the best ways that I can continue to decrease the potential likelihood of baby number two developing a food allergy. And I'll keep you guys updated.

Dr. Amna Husain:
I could talk about this topic forever. I find food allergies fascinating. So if you have any questions below, make sure you drop them in the comments. Share this with a parent who is confused or concerned about food allergies, perhaps. And make sure you subscribe, there are new videos every Monday.