ELIMINATION DIETS: The Science and The Scepticism
There is a lot of scepticism about Functional Medicine and the ancestral/geneticallly-appropriate nutritional therapy it promotes - particularly from within the conventional model. If you want to listen to one of the best, most rational and complete discussions about the role of Functional Medicine in chronic illness then I would recommend listening to this podcast episode from MindPump Media with Chris Kresser.
Functional Medicine is essentially lifestyle medicine - it addresses disease states by analysing the inputs to the body and how well each individual deals with them (genetically, functionally and metabolically). When the human body is assessed from this perspective you will always end up concluding that the healthiest thing for the human body is a Goldilocks zone where stressors are kept minimal, though appropriately utilised at times to build strength. And you will always find that the 'optimal' diet will be variations on a theme of real, whole, unprocessed foods that are nutrient dense.
And you can play semantics with the words 'real', 'whole' and 'unprocessed' until you're blue in the face - and sceptics do. But you can't really argue with nutrient density - by which we mean that the best choice for most of our nutrition will be foods that, per calorie, contain a lot of the micronutrients which are essential for every physiological process.
Now of course, this isn't a rule and there are variations. There are times when the emotional and social contexts for eating certain foods becomes of bigger import than the nutritional profile of the foods consumed. But generally speaking, and most of the time, this is a good rule of thumb.
This nutritional recommendation suggests eliminating obviously less wholesome foods (sugar and confectionary, for example). But, when it comes to nutrient density and overall wellbeing, this way of eating would also recommend minimising or eliminating some of the foods that we know - proven in the scientific literature - can be inflammatory and/or aggravating to the digestive tract or immune system of many individuals.
It's this bit that really riles people, it seems. Particularly those who feel that nutritional regimens which advocate any form of food restrictions or avoidance are no better than licenses to justify an eating disorder.
In the coming weeks I hope to discuss, in some depth, the intersection between gut health and eating disorders - and how, whilst some people view the nutritional recommendations for intestinal wellbeing as triggering to the psychological components of eating disorders, I actually think it is a far more complex situation than that, requiring more intellectual awareness of the true intersection where digestive function and psychological wellbeing meet.
But as background, today I wanted to share the reasons WHY we would recommend any form of elimination in the first place. Instead of focusing on just the removal of a few foods, I want to discuss the extreme: Elimination Diets in the form of the Autoimmune Paleo Protocol. The why, the how and the science behind it's necessity and how it works.
The Science
Here I am going to précis the scientific information and explain why - eating disorders aside - the science behind Elimination AND REINTRODUCTION actually works.
When it comes to AIP we are intentionally removing foods based on their known capacity to aggravate an immune system which is already hyper-alert. Even in normal, functioning, healthy individuals the proteins, compounds and nutrients found in foods such as grains, dairy, legumes, refined sugars, eggs, nightshade fruits and vegetables and nuts and seeds are slightly inflammatory and they do cause a slight up-regulation of immune activity. In fact - this is literally what happens when we eat anything - our immune system is prepped and ready just in case because we are bringing something 'external' into the body, which can carry adverse consequences.
That said, most people are completely fine dealing with whatever foods they take in. In autoimmune conditions, however, the response from the immune system is like turning the volume up on a inflammatory cascade that is already quite loud. I am not going to go into all the mechanisms of activity and immune function here - that can be found on the AIP page linked above. Suffice to say, the justification for removal of any foods stems from a generalised, scientifically proven awareness that the compounds in those foods can, in some (and, let me be clear, not in all) cases be aggravating, inflammatory and immune activating.
We remove these foods not because there is an innate allergy to them, but because an immune system in distress is like a raging fire. Every small piece of kindling (the inflammatory foods) put into the body whilst in this state will increase the inferno. The removal of foods starts - slowly - to slow down the rate at which the immune fire burns.
This works because the immune system is based on so-called 'memory'. Our adaptive immune systems 'learn' to react and they adapt to the stressors by making and creating inflammatory responses and immune killer-cells to tackle the things that we are exposed to.
But the immune system isn't an unchecked fire of inflammatory and killer cells - because that would be energy intensive. Instead, the initial inflammatory, immune response at the presence of an antigen comes from one branch of the immune system. There there is a second, complementary branch of the immune system which brings down this reaction. It's like a seesaw of reactivity and calming the reactivity: where the calming actions are an effort to lower a hyper-inflammatory state.
The consequence of this can be that we really don't know what foods are affecting us, nor do we identify certain foods as particularly worse than others. The reactions are constantly being kept just about under control by the body. What must be understood is that both of these branches make highly specific T cells, and highly specific regulatory T cells - they match perfectly.
What happens when you eliminate antigens, or foods that are seen as 'enemies' by the immune system, is that the reaction immune cells eventually stop being produced. Your body doesn't make anything that is redundant, and after some time not 'seeing' foods that have previously been pegged as enemies, the immune system no longer creates a host of killer T cells. Simultaneously, the regulatory T cells stop being made as they too are no longer necessary.
It is this beauty of quelling and quenching the fires (and the regulation of the fires) that allows anyone facing an autoimmune condition to start to slow their immune reactivity down. By removing the need to react (and regulate) against so many potentially aggravating foods, the entire body can start to calm and settle. This is accompanied by other, general lifestyle and psychological measures which also help to allow peace to descend into the body of those with such chronic illnesses.
The Scepticism
The magic of Elimination, as I have always said isn't actually Elimination. It is this word which gets those who feel these approaches are all about thinly veiled eating disorders annoyed. Elimination, Restriction, Avoidance - they all smack of foods being labelled 'bad' or 'forbidden', and the word "Diet" doesn't help either - because it brings up the concept of weight loss regimes.
No - the magic of Elimination is the information gained at the point of REINTRODUCTION. Whilst it is vital that the immune fires are quenched, it is more vital that anyone challenged with autoimmunity actually identifies whether there are any real food triggers or not.
As I said above, not every one of the foods eliminated is a real trigger. It simply can be aggravating when in a state of high inflammation. By calming the waters - and this can take months or even a year or two, depending on the severity of the issues - what you end up with is a system that is more at peace and more able to regulate its own inflammatory responses.
The real beauty of this process, however, goes back to the reactive T cells and regulatory T cells above. People sometimes assert that they were 'fine eating x' before an Elimination Diet but that the Elimination Diet caused their sensitivity. The truth is rather different. Instead, what is happening is that the regulatory T cell branch of the immune system dies down far quicker than the reactive T cell branch. This is common sense, really - our bodies take the path of least resistance, always. If a reactive T cell is no longer being seen we'll quickly stop making its regulatory partner because it is quite safe to do so. We'll hang on to some reactive T cells (and definitely the memory cells) for longer - because it's much more dangerous to no longer have defences than to no longer have regulation for those defences.
And so, the regulatory T cells disappear... the reactive T cells remain, though are less and more dormant. Then you eat the food - and instantly there is a response from the reactive T cell branch. This response isn't any more, bigger or greater than previously - but it will feel it because this time there are no regulatory T cells waiting to bring down the reaction.
Proper AIP
Now, normally I don't go around insisting that there are right ways and wrong ways to do things. However, this is an area where I am a little bit more specific, though not in the food rules and the restrictions, though it has to be done thoroughly and completely (and in the right order) for an Elimination Diet to prove actually useful.
No - the prescription I have for AIP is one of perspective.
In no way throughout the transition into an AIP diet should any of the foods be portrayed or thought of as 'enemies'. Just because our immune system is identifying them as such, doesn't mean it's actually right. Yes, sometimes we have genuine sensitivities to things and we'll never be able to reintroduce them - but this isn't the way to enter into the experiment of reintroduction.
The reason for this is that the mind is powerful when it comes to digestive, immune reactivity and nervous system activation. We have the power to sensitise our immune system simply by feeling hyper-alert as we sit down to eat. I will discuss this (and the nocebo effect) more in the next writing I do on Leaky Gut and Gut Health/Eating Disorders, because this is where the psychological and emotional and gut really merge.
For now, suffice to say, the relationship between gut and brain is BI-DIRECTIONAL. This means that we can sensitise ourselves to react AND we can be immunologically sensitive. It's not either/or - it's not that you should be able to eat everything and the reactions are all in your head (as some would have you believe). Nor is it a case of all the reactions are hardwired physiological sensitivities that are ingrained, lifelong and are entirely physiological.
This means that the Elimination Diet has perhaps been poorly named. It gives the impression that the whole point is removing aggravating foods. But actually, the foods are only aggravating to an already aggravated immune system. There is no 'bad' food here, and that's not what we're saying when any Functional Medicine practitioner recommends this course of nutritional approach. Instead, we are recommending a temporary avoidance of foods that can act like red rags to a bull... but it's a means to an end.
That end is food INCLUSION. The healthiest diet is, actually, the broadest diet that your body can thrive off. This is why doing AIP 'Properly' is about seeing it for what it is - it is just one tool (in a kit of many) to quieten the noise of a raging immune system.
It should also be looked at as a staged process. What you can bring back onto your table in the immediate reintroductions after a period following AIP strictly is unlikely to be your final diet destination. The immune system, and our bodies, are mutative - forever adapting and changing to the entire situation in which we find ourselves. This means every element from stress, environment, job, sleep, exercise, amount of sunlight etc, are all 'ingredients' that form foundations of health. Any one of these can alter tolerance, immune activation and general wellbeing.
So the science of Elimination is well founded but the scepticism may just be founded on having the wrong understanding of Elimination Diets and what their purpose and role is.
That said, it is very true that some see an Elimination Diet as a legitimisation of their fears of food and/or a route to weight loss. It cannot be denied that some people will use tools like an Elimination Diet as a way to lose weight or feel better and more in control of their body and their lives. This would classically be described as disordered eating.
And yet the lines between autoimmune conditions, eating disorders, immune sensitivities, physiological illness, food intolerances, gut health and emotional wellbeing are undoubtedly complex.
It is common and relatively easy for a period of disordered and restrictive eating to create gastrointestinal complications which impacts digestive health.
It is also common that emotional relationships with ourselves and the food that we eat affect our digestive function, literally altering how well we can break down and absorb the food we eat.
And it is also accurate to say that a lack of ability to effectively digest food can create a reluctance and unwillingness to eat - particularly nutrient dense foods which require proper enzymatic breakdown, such as proteins and fats.
Likewise it is possible for gastrointestinal complications such as intestinal permeability and microbial imbalances to disturb the neurotransmitter and biochemical balances throughout the body and brain...
This means that gut health can create psychological issues, just as much as psychological conflict can result in impaired gut health.
It is this bi-directional relationship that is the tight rope I walk with almost every one of my clients - how to navigate the food world, utilising tools of elimination without triggering paranoia about food, addressing gastrointestinal complications without ever forgetting that emotions impact the gut. It's not enough to dismiss food intolerances as psychological issues or 'false fears' which endorse food avoidance. But simultaneously it is also not enough to state that it is food reactions which create illnesses in people.
It is this tight rope and complex inter-relationship that I will go on to discuss in a follow-up post to this article. I will explain why using rolling eye emojis after the phrases "leaky gut" and "food intolerances" does nothing to support those individuals for whom eating has become a traumatic process - and dismissing their food avoidance as disorder does nothing to rebuild their relationship with food or themselves, no matter where the origin of food sensitivities comes from. It also denies perfectly valid and peer reviewed science, which is of concern to me when the individuals dismissing the science laid out above profess to be based in science themselves.
Stay tuned - especially if these last sentences seem a bit cryptic - and I will explain all in my next article. For now, to conclude on Elimination Diets:
They are a tool - and a means to an end - and they work. They are not designed to label foods as bad, nor to endorse restriction and avoidance as a way of life and a long term therapeutic 'solution' to all of your issues. Instead, these are temporary interventions from which information can be gained. If this is NOT the way your Elimination Diet has been presented to you, and you are clinging onto it months or even years later having made very few reintroductions - my next article will be very interesting and useful for you to read because I will explain how eating is, and always will be, emotional. Sign up to my updates and/or keep an eye on my social media and I'll tell you when my next post live.