Transcription
Welcome to Genetics Decoded. I'm Sharon Palmer, your host. Please note that the information presented in this podcast is not medical advice. It is just general information.
Today, we're going to look at the genetics around food intolerances and allergies. I hope you enjoy.
Welcome. Today, we're going to be looking at the genetics around food intolerances and allergies. Now, when I say that to you, did your little ears pick up and you thought, "Oh, I'm really interested in that"? Or did you do a little bit of an eye roll and a groan and think, "Oh my goodness, all these people with all of these food intolerances, just a load of rubbish"? What that really shows us is there's an enormous amount of confusion in the marketplace. And a big part of that is because we've got some real limitations around our current ability to identify our food intolerances.
So, what we're going to look at today is how we've got some real limitations around the current methods in which we identify our food intolerances. We're going to see how genetic research is giving us much better insight into identifying them, kind of really cutting through all of the confusion and making it so much easier. We're going to look at how you become sensitized. It's always really interesting. I talk to a lot of practitioners, I talk to a lot of patients, and I go, "Well, why are you gluten intolerant or why are you lactose intolerant?" And sometimes I just get this absolutely blank look, like, "Well, I just am." Or I hear all of these weird and wonderful explanations as to why somebody would have that intolerance. And what genetics is doing is giving us a real understanding of why we have those food intolerances.
If you think that your sensitization to a food starts when you first put it in your mouth, well, then that's not true. It can start so much earlier. And this is where, too, knowing early what we're dealing with here is of a huge advantage. And we're also going to examine how these food intolerances are impacting on our health. A lot of people think, "Well, it's just going to equate into me having some stomach pains, no big deal, I can just live with it." But for some people, those gut issues are more than just a little bit of a niggle. They're leading to, you know, big sections of their bowels being cut out. But we also know that food intolerances are impacting on our health in so many different ways. The impact is significant and it's extensive. And genetics is going to really show how it is impacting. And then you'll get a much better understanding of why it's so important to really identify food intolerances and get those foods out of your diet if they're an issue.
In clinic, probably I see more people who have got gut and immune issues. People come in, and 20 to 30 years they're trying to find solutions to their indigestion, their gut pain, their diarrhea, their constipation. They are incredibly frustrated. They have often tried everything. They are confused. They've tried, they've seen multiple practitioners. There's often quite contradictory advice between these practitioners. They have spent a lot of money. They've tried a lot of supplements. They get to the point where they don't know what to do, but they feel that they can't stop because it's impacting quite significantly on their health.
I recently saw a young boy, six years of age, who literally threw up after every meal. And, you know, you can imagine as a parent trying to manage that. We've got women who have been on liquid-only diets, and that's because again, every time they eat, they're throwing up. I remember a patient of mine came in once after we'd done a program for her, and she said, "I've booked a, I've booked a flight to Sydney." And she was incredibly excited about that. And the reason that she hadn't flown for over, you know, 10, 20 years, is because she said, "There is no way that I'm hopping on a plane with one to two little toilets and all of those people," because things are just so unpredictable. And so people's lives can be really impacted when they're reacting to foods. And so they don't want to give up. They want to keep trying to find a solution. And what I know is genetics can really give us, you know, give people a lot of insight and a lot of help here.
You may think that there's just a few people that suffer from gut issues from indigestion, thinking that they're reacting to food, but it is much more extensive than that. It is now recognized as a global health burden. Places like the US, sometimes, you know, some of the research is showing it's costing the US healthcare billion dollars a year, not millions, but billions of dollars. So people are out there trying all of these different solutions. They're engaging with the healthcare system to try and find solutions.
We also see that the rates of food intolerances and allergies are increasing. Now, that's not because we're ending up with more genetic risk factors. Our genes change much more slowly than that, but our genes are interacting with our environment. So what we're seeing as our food choices are changing, as we're moving into more manufactured foods, is our exposure to certain food ingredients is changing. And so we're seeing that the rates of celiac disease are going up. And so we've got to look and understand the real importance of going in and identifying these food intolerances before they really have an enormous impact on our health.
There are enormous limitations with the current model of trying to identify food intolerances and allergies. What we usually see is people start to do these food challenges. They start by eliminating the food. So someone says, "Remove it all." And that's kind of a little bit of what the current FODMAPs diet is. It's like, "Well, we don't know what you're reacting to, remove everything, have a very limited diet, and then when things have settled down, begin to introduce one food at a time and see if you react." And, you know, the research is really clear, it doesn't work. There's no correlation. And you have to look that when we put a food in, you know, when you eat a food, it's quite likely got some gluten in it, or it might have some cow's milk, or it might have some histamine. If you do react, how do you figure out what it is that you're reacting to? So there's enormous challenges with these elimination diets and then the reintroduction of food.
We also assume that if if you're reacting to a food, that you're going to end up with these obvious gut symptoms. But many people who have even quite significant food intolerances don't show up with any obvious gut issues. Symptoms can be very broad across a whole range of symptoms. And, you know, they've done research where they've gotten people to try and identify what they're reacting to. Sometimes people can have key symptoms and they get it completely wrong. They think, "Oh, it's lactose that I'm reacting to," and maybe it's actually gluten. So, you know, it's very, very difficult to kind of pinpoint what that is. We know that symptoms, so a lot of the things that could be associated with food intolerances could be impacted by other risk factors as well. So the whole thing, we know, is that trying to identify your food intolerances by just removing and adding foods, it doesn't work. And most people we see at a clinic level have gone through that process and they just go, "I'm just confused." Or sometimes, "I eat a food and it causes a problem. The next day I eat it and it's not such a big issue. Like, where do I go from here?"
So, what we're going to do is really look at how genetic research is kind of cutting through all of this confusion and giving us much, much better insight. Researchers have identified what the genetic risk factors are, the variances around a whole range of different foods, and particularly the ones that we know that if they're going to be a problem, most people are going to fall into these categories. So we understand the genetics around gluten intolerance, around who reacts to oats, around lactose. Now, what I see at a clinic level, if people think that they're reacting to dairy, they make the assumption that they're lactose intolerant. But dairy is confusing. You could be lactose intolerant, you could have a cow's milk allergy, you could be reacting to casein. You can have all of those three operating at the same time, or any combination of those. And so again, you want to know exactly what part of dairy you are reacting to, because that's going to really determine what you can and can't keep in your diet.
We know that peanuts, and there's there's there's, you know, people are very aware of peanut allergy. We often assume that it's just this anaphylactic response. So unless your throat swells up, everyone thinks, "I don't have a problem with peanuts." But there's a lot of different genetic risk factors around peanut allergy. Your immune system can be reacting in ways that you may not even really be aware of. We know the genetics around eggs, and we also know the genetics around histamine intolerance. So if we look at what are the main problems, that group of foods are the majority of our food intolerances. And your genetics can go in and identify all of them. And you don't need to do a food challenge. You don't need to remove those foods. You simply go in, you get your genetic data, and you look at the genetic risk factors. You will either have those risk factors or you won't. And therefore, we can then go, "This food stays, this food goes." And, you know, the problem is, is that until you get a big picture of all the foods that you need to be addressing, trying to do one at a time is very ineffective.
If we have a look at why we have these food intolerances, when we look at your genetic data, it's a huge amount of data. But there's a key part of your genome called the Human Leukocyte Antigen system. It's called the HLA system for short. It's also often referred to in the research as the MHC system, that's the Major Histocompatibility System. They're exactly the same. But it's a key part of your human genome. And what researchers are finding is that a lot of our food intolerances are located in this part of the genome. And what's also really interesting is that, you know, genetic variance, mutation show up at different rates. Is that this HLA system is one of the most mutated parts of the human genome. And so what that means is that our reaction to food is very individual. What you may react to may be very different to someone else. There's no food that is inherently allergic or or that everyone's intolerant to. It is really our genetics that is determining whether we're reacting to that food. And so there is just simply no way from guessing or as I said, through all of these food challenges that you can do that.
So, this is what your genetics is doing. It's allowing us to go in and pull out the genetic data in that part of the genome and simply reporting on it. It becomes really simple, really easy, and incredibly accurate. You know, I've been using genetics at a clinic level for over 13 years now, and it's so easy once you've got your genetic data to show people what their food intolerances and allergies are. And I kind of forget how difficult it can be. But when people come in and they're like, "I just don't know what to do. I think I'm actually intolerant and allergic to food. I seem to be reacting to to everything." So, you know, you can really go in and look.
The HLA system is really, it's a big system in which the immune system becomes very strongly involved. But we also know that there's a range of food intolerances that are directly related back to our skin barrier. They're actually called skin barrier defects. Now, we have this compound, this protein in our skin called filaggrin. We know that your skin is a semi-permeable membrane, so it lets things in. And you've actually got a lot of your immune cells sitting in the dermal layer. And so, you know, these skin barrier defects are a really big player around food intolerances. And so again, we can go in to see if people have these filaggrin mutations. And that also means, depending on which or where your mutations are, it's going to really make a big difference as to what your interventions are.
If it's an HLA mutation in which the immune system is reacting, you're going to need to be really careful of the foods that you're eating because when those foods come in, you'll have an immune reaction. But if you've got a skin barrier defect, well, then you want to really pay attention to your environmental factors, like, you know, what are you putting on your skin? What are you exposing yourself to? And knowing that your skin barrier defects can lead to sensitization around these foods long before you put them into your mouth.
If we have a look around the HLA system, the food allergies that are really HLA based are things like our gluten, our oats, our peanuts, our egg, and our cow's milk. All of those, we need to be really careful about whether they're coming into the diet if you're intolerant to. When we look at skin barrier defects, what we see is peanuts, eggs, and milk. That should very clearly show you that there can be multiple ways in which we begin to react to foods, not just through eating foods, but through skin barrier. And so for some of these food allergies, you need to be doing more than just removing these foods from the diet. You need to be looking at environmental factors as well.
We also know that there are a number of food intolerances and allergies that are related back to enzyme activity. So, one of the things that people are often very aware of is lactose intolerance. In fact, lactose intolerance is the most common genetic variant in the world. And we know that it's all based around the activity of an enzyme called lactase. We know that there's something called hereditary fructose intolerance. It's lack of an enzyme, or that the enzyme is just not working very well, and people can't metabolize their fructose properly. And it builds this toxic metabolite, builds up in the liver, and can do an enormous amount of damage to the liver. And, you know, that's one of the things that I always screen for is hereditary fructose intolerance. What I know is that it doesn't occur very frequently. Of all the people that we've identified at a clinic level who had hereditary fructose intolerance, not one of them knew it. What they knew is that they had long-term issues around their health that when they ate certain foods, particularly fruit that had a lot of sugars in it, sometimes they started to vomit and get really sick, and often started to have an aversion to things that were very sweet. But nobody knew that they had this hereditary fructose intolerance.
We also know people are just starting to hear. I'm seeing a few podcasts where people are talking about histamine intolerance. And again, it's all related back to an enzyme activity. In some people, the enzyme that breaks down your histamine is working too slowly, and therefore you start to react. But, you know, histamine is in so many foods. Trying to say, "Well, I'm just going to remove all my histamine foods," is almost impossible. The thing that I want to really kind of show you here is that there are multiple ways in which the body can react to these different foods. Your genetics is very good at clearly showing you what they are. And then once you've got that information, you then begin to act upon it, and it can make an enormous difference.
Let's look at how we become sensitized to these foods. A lot of people think, "Well, when I start to eat foods, I'm going to very quickly find out whether I've got any reaction or not." But the research is showing that we can be sensitized across the placenta. We can be sensitized through breast milk. We can be sensitized through a skin barrier defect. And then finally, when we put food in our mouth, we can also have that reaction. But what we're finding is, if we've actually been sensitized in utero, or through breast milk, or through skin barrier defects, when we finally put that food in our mouth, this is when we can have quite a massive reaction. And so again, you want to kind of use your genetics to find out where that exposure is coming from, where that risk is coming from.
And this is why I always recommend, you know, like people go, "Well, when should I screen for my food intolerances?" And I go, "The sooner the better." So for women who are planning on a pregnancy, go in and screen your food intolerances before you get pregnant. Therefore, if you're having these food intolerances, they're not some of these immunoglobulins that are being triggered. Won't be triggered because they actually have the capacity to cross the placenta. There's not a lot of things that can cross the placenta, but some of these immunoglobulins triggered from food sensitivities have that capacity. And then also knowing so that once your baby is born and you're breastfeeding, again, this sensitization is not occurring.
If it's a skin barrier defect, and you think, "Well, as long as you don't put," let's say you've got a skin barrier defect and it's a risk factor for peanut allergy, and you think, "Well, I'll just not feed my children peanuts." But what's quite surprising is researchers can isolate peanut protein in your household dust. So again, you know, your children are crawling around on the floor, they're picking up and eating things. And so skin barrier defects can lead to this early sensitization. By having this information, you can control a lot of those factors. And then I always go, "Before you introduce foods into your child's diet, go and look at your food intolerances."
What we're clearly seeing is that if we get in early and we simply don't put these foods in in the first place, we can change a whole lot of risk factors. Certain pathways don't get triggered. Inflammatory pathways don't even kind of begin the process of leading down to autoimmune risk. So go in and look early. But, you know, it's never too late. Like, if you're 50 or 60 right now and you think, "It's all over," think again. You know, the oldest person we've done was a woman in her 80s. She was living in an age care facility and she started to have all of these problems around reacting to food. So we went in, we looked at all of her food intolerances from a genetic point of view, and things really settled down. Age is no barrier here. The earlier you look, the better, but it's not too late.
And I think one of the most important things you can do with your genetic data is go in and identify these food intolerances. The thing is, food is coming into our bodies multiple times a day. If you are reacting to it, it's triggering a lot of things in the background. And so it really is playing a major role on your health. It's not just, as I said, just whether you get a little bit of gut pain or a little bit of diarrhea after eating.
So, let's have a look at what some of these reactions can be. How can these food intolerances be impacting on our health? Well, first of all, it can be fatal. So that's not a good thing. So people who have got these anaphylactic reactions, so that's where the throat is swelling. We know that around peanut, but again, it can happen across a number of foods. There is a big call from researchers to start to genetically screen babies who have just been born so that we can go in. They have highlighted that we should be doing it around hereditary fructose intolerance, looking at some of the gluten mutations that are very strongly associated with celiac disease. So knowing that if we go in early, we can avoid some of this.
There's the obvious around gut and digestion, and that can be pain, bloating, diarrhea, cramping, indigestion. But two out of three people who have food intolerances and allergies don't get any obvious gut symptoms. So it really can be showing up in unexpected ways. We can see skin issues. So this is where we get redness or itchy skin, where we could have eczema or psoriasis. Your food intolerances and allergies are playing a big risk. If you know that you have these, if you're suffering from these, what you should be looking at is, "I should go in and look to see what these food intolerances are."
We can see around asthma and allergies and hay fever. So again, go in and remove the foods that you're intolerant to. It can make a really big difference to the risk and also the degree, the severity of your symptoms. And then we're looking at how it's impacting on the immune system. And this is where most people have really no idea of the extent upon the immune system. We can get your immune system impacted in many, many different ways.
There is something called an IgE response. So IgE is that allergic part of the immune system. And you'll often know that, you know, people who have an IgE response, they eat a food, and this is again where you can get that anaphylactic response. It's where suddenly your lips swell, or you get this rash, or something happens, you go, "Oh my God, what happened there?" That's an IgE response. And you can also go in and check your IgE levels in your blood.
We can have an IgG response. That's an immunoglobulin G. And this is one of the very few immunoglobulins that can start to go in lots of different parts of the body. And so again, as you start to trigger these immunoglobulins, it can start to impact in other parts of the body, which most people have no idea of that connection. We can have something called a STAT6 response. And again, it's all around how the immune system is working, our allergic response. We can see a triggering of a whole range of what we call these interleukins, these inflammatory cytokines. These food intolerances can trigger a lot of systemic inflammation. And we see a triggering of a lot of these T helper cells. And so this is again where we start to open up the door to a lot of autoimmune risk.
Now, autoimmune, there's a lot of people out there who have an autoimmune condition. If you do one of the first things you want to look at is your food intolerances and allergies because they are a direct risk factor for the development of autoimmune condition. And the big one of the big reasons is because of all of this immune activation that's happening in the background. We can get, you have these things called T helper cells, and they can be activated. And once you activate a T helper cell, it goes into the rest of the immune system and says, "Okay, let's go, we got to do something here." And, you know, this is one of the primary ways in which gluten begins to trigger the autoimmune disease called celiac disease. It starts by all of this autoimmune signaling happening in the background.
We can see that your IgG, this immunoglobulin G, can lead to the triggering of B cells, and then this is where you get these antibodies produced, and it opens up the door to all of this autoimmune disease. So it's not kind of all hocus pocus. If you really understand the mechanisms, you start to see why it's so important to find out how your body is reacting to these foods, especially if you're suffering from any of these conditions.
We also see the triggering of something called Th17. And that pretty much underpins almost all autoimmune diseases. So when you're eating foods that you're reacting to, if you're getting this Th17 response, you're getting this risk around autoimmune. And this is the thing that we want to do with autoimmune disease, with anything that we're suffering from. We don't want to be working on trying to just control the symptoms. "Oh, I've got a rash, let me put it, let me put a cream on it." What we want to do is go and look at what the drivers are. And your genetics is really effective at identifying these drivers.
We can also see there's a very strong neurological response to the foods that we're intolerant to. And again, it comes back to this IgE. Our brain is protected by our blood-brain barrier. You don't want a lot of stuff getting across the blood-brain barrier. Your body is very selective at what it lets through. IgE is one of the few things that can cross your blood-brain barrier. And we can also see that the inflammation that is triggered by your food intolerances through this IgG response can actually start to impact on the integrity of the blood-brain barrier. So as you break down the integrity, then things that shouldn't cross can begin to cross. And that's when you start to get into a lot of issues.
But we can also see that this breaking down of the blood-brain barrier, the triggering of inflammation within the brain, can then lead to neurodegeneration. And so again, as the blood-brain barrier becomes more permeable, this is where we see the risk of food intolerances around some neurological issues, issues around Alzheimer's, Parkinson's, schizophrenia, autism spectrum disorder. And so again, you know, we see a lot of information around this in the market. But knowing that your food intolerances should be screened here.
And then, of course, we've got all of this inflammation being generated. And, you know, if the body is inflamed, the brain is inflamed. If the body is inflamed, it's going to impact your health on lots and lots of different ways. One of the things I really see from a clinic level, people come in and they're so sore, they've got all these aches and pains, sometimes so severely that even trying to exercise is just too difficult. Everything hurts. And as we address their food intolerances, what people really begin to notice is those aches and pains begin to come down. And that's a real sign that inflammation is coming down as well.
In conclusion, let's have a look at how our genetic metrics can really help us around our food intolerances and allergies. First of all, your food intolerances and allergies have significant impact on your health. You want to know whether you have them or not. One of the best ways to identify your food intolerances and allergies is through genetic screening. It is very simple, it is very accurate, and doesn't require any elimination diets, any food challenges.
If you're going to use your genetic data to identify your food intolerances, make sure you're getting the information that you need. We will be covering in future podcasts, really going in and looking at some key food intolerances, looking at the genetics that underpin that, so that you get the information that you need so you can make the decisions that you need around your diet.
Thank you so much for listening to Genetics Decoded. If you enjoyed the episode, please remember to subscribe, like, and share. Tell your friends all about what we're doing because we truly are individuals. Your genetic data can be used for you to make much better decisions around your diet, supplements, and lifestyle. Join me each week to find out how.