Aidan:

Hello and welcome to episode 71 of the Ideal Nutrition podcast. My name is Aidan Muir and I’m here with my co-host Leah Higl. And today we’re going to be talking about food chemicals and intolerances, specifically talking about the IPAH elimination diet. This is a diet we’ve both had a little bit of experience with, working with clients and everything like that. It is a complex diet and it is also a complex topic.

I think it’s a complex topic because it probably affects most people in some way, shape or form. It’s just how much it affects people, whether we should really worry about it and how much we should do about it.

Leah:

Yeah. And I mean, for the people that really should worry about it, we’re talking about people that actually get symptoms that are affecting your life in some kind of significant way. So we’ll go into like what these symptoms might look like. But it can be IBS-related or it can be non-gut-related as well. But at the end of the day, if you don’t have any symptoms, you shouldn’t be following this kind of like food chemical elimination diet, because it’s really for a very specific purpose.

You could make the argument that limiting like certain food chemicals like in heavily processed food is probably beneficial for most people. But this kind of food chemical diet also does include just naturally occurring plant chemicals. So you know, it’s not just things like additives and preservatives that we’re trying to limit in regards to like quote unquote food chemicals. But yeah, if you don’t have symptoms, it’s not something you have to worry about usually.

Aidan:

Yeah, for sure. If you feel good…

Leah:

if you feel good, don’t don’t mess with it.

Aidan:

Yeah, exactly. So in terms of what symptoms we’re talking about, it’s very broad, like going through a list, we’ve got like IBS symptoms, headaches, hives, rashes, sinus issues, eczema, hyperactivity, fatigue and bunch of other stuff. And part of the reason this topic is so difficult is because almost everybody can identify having at least one of those symptoms. Like what percentage of population is fatigued? Like what percentage has rashes? What percentage gets headaches regulated? And what percentage gets IBS symptoms?

Like it suddenly becomes a large percentage of population having some form of these symptoms. So I typically only go down the route of like the full RPIAH elimination style diet or really looking at food chemicals deeply for people with relatively severe symptoms and more so if there’s some form of linkage like if they say my symptoms get worse when I do X thing that lines up with the RPAH elimination style approach.

Leah:

Yeah. There has to be some kind of link there. It’s not like someone’s going to walk in and say, I’m feeling really fatigued and I’m going to go, let’s do a food chemical intolerance, like elimination diet. So yeah, that’s a big one. What chemicals are we actually referring to? So there are three main food chemicals that are part of this process and that’s salicylates, amines and glutamates. In addition to that, there’s a pretty long list of different kinds of like food additives, including like food colours, preservatives, flavour enhancers. But generally it’s important to acknowledge that a lot of these are like food chemicals like salicylates, amines, glutamates are just found also naturally occurring in foods. So this food chemical elimination diet can get pretty restrictive because they’re in just so many foods.

Aidan:

Yeah, that’s what makes it so complex as well because if it was just additives, this would be a simpler topic, which I guess like going through like what what foods these are found in like a little bit more deeply. Additives are the easy ones. Like if you get packaged food that has a long list of ingredients, like there’s a relatively high chance that there’ll be additives. One place I’d want to start before going through that as well is that we do have a food chemical elimination guide on our website and that has a list of all of these foods. So if you wanted to look at that, that is there. And you can find that in the show notes, which is not something that we have talked about much. Have we spoken about this?

Leah:

I don’t think we’ve ever mentioned our show notes, but we do them for every episode.

Aidan:

Yeah, so Hannah, who’s part of our team, she puts a lot of work into doing our show notes. So you can find show notes for every episode. But yeah, for something like this, you can go to the show notes and you can find this list of these foods. So if you want to look at this, you can find it. So there is a bunch of additives and you can look for those additives specifically on food labels. Going through the other ones, so we’ve got salicylates and salicylates are natural chemicals produced by plants as a bit of a defence mechanism against insects, pests, microbial attacks, those kind of things.

I find saliculates the most interesting one because of like, you know, the carnivore community, how they’re always like, plants have these chemicals in them to defend themselves. Like it does come from a grain of truth, like that doesn’t make a carnivore diet, the approach to go down. But there is a grain of truth to that aspect of it. And salicylates are found in lot of fruits, vegetables, herbs, spices, tea, coffee, beer, wine, a lot of plant-based foods have these. Amines are a little bit more complex and are found in a lot of foods such as fish, cheeses, sauces, chocolate, nuts, seeds, and some alcohol as well. And glutamates are often found in like fermented and extensively cooked foods as well. MSG is probably the most common example that most people know of this.

And then it’s also about the kind of amounts that they have as well in terms of like these things will be in a lot of foods, but some foods will just contain more of them than others. So like salicylates are probably in almost every plant-based food, just in different amounts basically. And as an annoying but simple guide, typically the stronger the flavour of the food, the higher the food chemical content as well.

Leah:

Which also makes the process hard because a lot of the food is very bland.

Aidan:

That’s why it’s annoying.

Leah:

So annoying for many reasons. But in terms of the process that you go down when you’re following this food chemical elimination diet. If you’ve heard of like the FODMAP elimination diet, it’s a very similar concept or process. So the gold standard to the RPAH elimination diet is to follow a low-food chemical diet for two to six weeks or until symptoms have gone away. Obviously symptoms are only going to go away if it is your symptoms are related to these food chemicals. But that is quite restrictive, like we said, so we’re cutting out a lot of different foods, we’re doing it for a decent amount of time. But then you systematically reintroduce these different groups of food chemicals and additives to see which ones are actually triggering your symptoms.

Now, whilst I say that like for most people like the FODMAP, low FODMAP diet, you might be able to do it without a dietitian, maybe. This one, I would say it’s very unlikely that someone could do it without some kind of help from a professional. It’s quite a complex one to do, so I would always recommend that. But we do have a full guide on our website that we’ll link in the show notes as well so that is available if it’s something you’re kind of looking at. But once you do this kind of following the strict diet reintroduction testing and you know what triggers your symptoms you can then find out what your threshold is for those different things that trigger your symptoms and then develop this individualised approach for you that is that is less restrictive overall.

Aidan:

And as another note, like tolerance also changes over time as well. So even if you go through this process, it can change. That’s another thing that makes this complex as well. And it’s another thing that it leads into that kind of carnivore discussion as well because if somebody goes carnivore, they also go low food chemical at the same time. But tolerance changes. And one of the things that a lot of literature on this topic talks about is if you take away food chemicals, this sounds weird, but your tolerance to them also drops, likely. And when you reintroduce them, your symptoms can be higher as well that creates another kind of, it’s almost like a self-fulfilling kind of prophecy if somebody goes completely low food chemical that when that..

Leah:

And then you reintroduce it. Yeah.

Aidan:

Yeah. So that adds a layer of complexity into this as well. In terms of the next topic, we really want to talk about like, what is the success rate of this kind of approach and what does the research on the topic show? Basically, this appears to be the best method we’ve got. It’s the closest thing to an evidence-based approach we’ve got for identifying which food chemicals are causing symptoms and how to manage it as well.

But just because it’s the closest does not mean it is a perfect approach. I think there’s still a lot of room for improvement, a lot of room for more evidence to come out in this space. There is a ton of anecdotal evidence as well. Like if you Google, you can find it everywhere. And there’s a bit of research. Mostly coming from the Royal Prince Alfred hospitals, the RPAH. And a bit of this research has positive outcomes, but it is still mixed.

One of the biggest areas I always highlight when talking about this is I talked about MSG, right? And if you look at research on MSG by itself, it has never been linked to headaches in comparison to placebo. There is a ton of anecdotal evidence that it causes headaches. A lot of people will talk about it. But in the research, it has never been found when compared to a placebo. But it is incredibly common for people to report symptoms when they add it back in following the elimination diet.

I don’t have an explanation, but that’s not in comparison to placebo. And we kind of see in a lot of areas where symptoms like headaches or IBS and stuff like that, that symptoms can be caused for a variety of reasons as well. I’m going to use an example about creatine supplementation. If you compare creatine to placebo and you look at GI symptoms, creatine rarely increases GI symptoms. It does, but it’s incredibly rare. Like we’re talking a very small percentage of people noticing symptoms.

If I give a client anecdotally, like 30-something percent of people notice symptoms. And like that’s where it gets really wild and that’s where I look at it, that kind of perspective for like headaches and MSG and stuff like that. Being like we can also get a bit of a misrepresentation if we’re not comparing to placebo.

But on other topics, some of the research also looks particularly promising. One of the biggest examples of this I can think of is eczema. So it seems based on small sample size research, not large sample sizes, but around 75% of people with eczema show significant improvement when following a low salicylate diet. That’s…

Leah:

It’s pretty huge.

Aidan:

Huge. Like an eczema is something that like no single dietary approach seems to have like that large of an impact. So like in terms of helping 75% of people. So that’s quite huge. Obviously, I’d love to see larger sample sizes and stuff like that. And it also still comes alongside the challenge of.

Is it worth it for some people? Personally, I have a client who already has a history of disordered eating who has been referred to me for eczema. And I’ve got the challenge of being like, do I get them to go low salicylate when they already have issues with food flexibility? Do I make it more restrictive? And then it’s weighing up the pros and cons and stuff like that. Fun fact, in that case, I’ve chosen not to, but it is a challenge, obviously.

Leah:

For sure. And I think there’s like, there are many downsides of this type of approach. Firstly, generally, it’s hard for anyone who’s going to be following it. It’s a hard restrictive thing. But then bringing in like disordered eating or a not great relationship with food, it’s probably then also just not advised to pop over the top of that. Even like this study on salicylate restriction that you found. like,

It was a study that looked at salicylate restriction in children and they found that adverse effects occurred in 31 out of 66 children in that like it was like nutrient deficiencies food aversions that started to develop. But also for children were reported to develop disordered eating. So even just like maybe even if you don’t have issues with food and then you’re following this very restrictive approach you make develop some anyway, like that’s always a risk, I suppose. And then if you already have issues with food on top of it, probably more of a risk for you. So that is a potential downside. And that’s just to list late. So that’s not even taking into account that the food chemical elimination diet as a whole is way more restrictive than just that.

So yeah, there are a lot of people that I won’t use this approach with for a multitude of reasons. I’ve also tried to and have had some success using it with people who are vegan and who have had these kinds of symptoms, but that in itself is tough. So, you know, if you already have other restrictions that you’re working with and then you add this on top, again, that is that’s a huge downside to this approach.

Aidan:

Yeah, I think that the children aspect is really difficult as well. Like it’s tough enough to understand nutrition as it is. And I also think like people who are very black and white thinker struggle with this. Even with FODMAPS, I’ve run into issues working with certain people where I’ve talked about high FODMAP foods and they’ve been like, I thought this was good for you. Like it could be like garlic or onion. And like, I thought garlic and onion were good for you. And I’m like, that’s not what this is about. It’s about symptoms. This can still be good for you for all these other reasons, but cause symptoms. And in this case, yeah. And it’s so tough going through that explanation.

Leah:

It can warp your, I guess your thoughts around different foods in a way that’s not super helpful.

Aidan:

Yeah. So I guess we also want to be talking about, there easier ways to do this so I have quite a few thoughts on this. The first one is you can do a modified version of this so the strict low-food chemical diet is obviously very very restrictive. As an example of how restrictive it is when we’re looking at fruits there is one fruit that is fitting the criteria of low food chemical, or one common fruit that is fitting the criteria, and that’s pears.

Leah:

It’s not even a good fruit.

Aidan:

It’s not even like, yeah. And it’s like, if you change it to a medium food chemical approach, you’re looking at it in terms of being pears, bananas, and apples. So you’ve got three types of fruit. it’s not overly exciting. But you could do a modified version of that, or alternatively, you could pinpoint one group that you think might be super relevant for you, like for example that salicylates thing we talked about with that eczema thing, like well maybe we just do like one of these aspects or maybe we look at first limiting those other like additives and stuff like that and going for more and more of these like unprocessed foods and stuff like that.

That’s another starting point and an interesting topic that I think about a lot with a lot of people is potentially reducing fruit and vegetable intake because that’s going to carry over to reducing salicylates and some people that can improve symptoms with like IBS symptoms in the low FODMAP diet, this is one explanation that some people have that’s like you go low FODMAP, you likely reduce food chemicals, firstly by eating less packaged food, but secondly you probably reduce your fruit and vegetable intake because you have less that you can have.

And that’s where it becomes a really complex topic in the grand scheme because we know more fruits, more vegetables very clearly leads to improved health outcomes on average in an almost linear fashion. But then we’re just balancing with symptoms being as like, well, ideally, you go as high as you can with those things without having symptoms that seriously affect your quality of life or anything like that.

Leah:

Totally. So like overall, like the RPAH elimination diet is an incredibly useful tool. It does a good job at identifying and managing food, chemical intolerances when you have symptoms from those things, but it’s absolutely not without its downsides. It’s really hard. It’s very restrictive. You have to follow it for a good portion of time. You probably need a professional to talk you through the process but it doesn’t mean that it’s definitely not worth using because it is useful. So if it’s something you’re considering, like I said, I would probably speak to a dietitian to see if it’s an avenue you should go down. But it’s good to be aware of because I feel like a lot of people are just not aware of food chemical intolerances generally.

So this has been episode 71 of the Ideal Nutrition Podcast. If you could leave a rating and review, that is always greatly appreciated. But otherwise, thanks for tuning in.