Food sensitivities: Why you react, and how to identify your trigger foods

Food can be a minefield!

Food provides the building blocks for life, can act as medicine, and is associated with celebrations and our most memorable times, sharing with family and friends.

Yet, food can also be a source of fear and confusion, ill-health, and toxicity in the body. We can spiral into a hole of poor gut health and inflammation, reacting to more and more to foods, still not knowing exactly which foods are triggering us. Some people then end up eating a severely restricted diet and become afraid of food in general.

Common digestive symptoms include bloating, wind and diarrhea. We may not have yet connected the dots between what we eat and seemingly unrelated symptoms such as migraines, joint pain, eczema, fatigue or sinus congestion, and mood disturbances.

Adverse food reactions fall into four causal categories.

  1. Immune system mediated – antibodies and inflammation in response to particular foods
  2. Digestive tract mediated – e.g. enzyme dysfunction such as a lactase deficiency which results in an inability to break down lactose, found in dairy
  3. Gut fermentation mediated – high FODMAP foods may lead to a worsening of symptoms. Read about the Low FODMAP diet here.
  4. Something else in the food e.g. salicylates, oxalates, sulfur, histamine, lectins

This article will explain how immune-system mediated over-reactivity comes about, and how to identify which foods are may be affecting you. My aim is help you understand the reasoning behind the interventions I suggest in my second article (released in the next week or so) on lessening these reactions.

Immune Tolerance

A huge proportion of our immune system lives within the lining of the Gastro-Intestinal (GI) tract. The immune cells that line our GI tract have two critical jobs:

1) Defend us from potentially harmful ‘pathogens’ in our guts (e.g. bacteria or viruses that are a threat)

2) To not react to food that we eat, and the bacteria in our gut. The immune system should actively suppresses a reaction to these.

It turns out that most of the time, the role of the immune system is actually NOT to respond to things. It should only react when there actually is a real threat. This concept of an appropriate response to our food and environment is called Oral Tolerance. Oral intolerance normally develops through a baby’s contact with their parents and breastfeeding. The first 1000 days of life are therefore very important in establishing immunity in general.

If we lose oral tolerance, we can start reacting to foods that we eat, and often we also develop increased intestinal permeability (leaky gut), inflammation, and digestive discomfort. This may progress to the stage where our immune system starts targeting our own tissues and organs (auto-immunity). And so it’s important to work on improving gut health not just to reduce food sensitivities themselves, but also to prevent progression of an auto-immune process.

Leaky Gut and Loss or Oral Tolerance

Increased intestinal permeability, commonly known as leaky gut, can be a contributing factor to loss of oral tolerance, but it isn’t the only mechanism involved in food sensitivities!

Mechanism of Intestinal Permeability

With a leaky gut, larger molecules, such as undigested food particles, toxins and micro-organisms, can enter the bloodstream through gaps, called tight junctions, between the cells that make up the gut lining.

The immune system doesn’t recognise these foreign molecules, raises the alarm that an invader is present, and then makes antibodies specific to these molecules. If those macro-molecules are gluten, your body will make antibodies to gluten. If it’s dairy, your body will make antibodies to dairy. A loss of oral tolerance to that food is developing..

A leaky gut can also be associated with a general loss of tolerance to a range of foods. In which case, you may find yourself reacting to more and more foods.

Then the question is not how do you avoid those foods but how do you calm the over-reactivity of the immune system in your gut, as well as heal leaky gut. The goal here is to reduce the hyper-reactivity to a whole range of foods, rather than focus on tolerance or avoidance of individual foods. We will cover this later in this article.

Dendritic Sampling Cells

Dendritic cells are a type of immune cell that sample the environment inside the gut (the gut lumen), providing an inflammatory signal to the rest of the immune system if they find something which they deem to be a threat. It’s vital therefore that they aren’t over-reactive (like Donald Trump on Twitter!).

So dendritic cells can initiate an inflammatory response to foods in the absence of leaky gut! This is important as it means even fixing a leaky gut, doesn’t necessarily mean the inflammatory response in our gut will develop normal tolerance. It may take extra work to support the Dendritic cells and T-Reg cells in our gut, as well as the spleen and liver!

dendritic cells sample antigens from the gut lumen

One of the ways our dendritic cells are protected from over-activation by the contents of our gut is through a natural layer of mucus that lines our gut. This mucus contains a protective antibody called secretory IgA (SIgA). SIgA also take some of the pressure off dendritic cells by surrounding bacteria, viruses, and problematic proteins.

An overgrowth of yeast, such as Candida in the intestine, aswell as other bacterial and viral overgrowths, psychological and emotional stress, and immune suppressants can all decrease the amount of protective SiGA and this has the potential to allow over-reactivity of our dendritic cells, and an inflammatory response to food.

It’s important that you chew food well, and have adequate stomach acid and digestive enzymes as partially digested food can also over-activate the dendritic cells

Regulatory T-Cells (T-Regs)

Dendritic cells surround foreign proteins and transport them to the lymphatic system. There, they present the protein to T-Reg cells. It is the T-Reg cells that determine whether the immune response should be one of activation or tolerance. If a response is initiated, B cells within the immune system start to create antibodies to that protein.

The good news is that we can support out T-Reg cells through nutrition and lifestyle. I’ll cover this and what else we can do to reduce food sensitivities in my next article in this series.

Testing for Food Sensitivities

The first step you should take when working to lessen food sensitivities is to temporarily remove trigger foods from your diet. We can then work to improve your overall gut health so that you are better able to tolerate foods without an exagerated immune response. But how do you know all the foods that you are reacting to?

One of the best ways to identify food sensitivities is an elimination diet. An elimination diet involves removing all suspect foods, that may be triggering the immune system, for a limited time (at least 3 to 4 weeks). After this period, foods are re-introduced systematically, every two or three days whilst keeping a close eye on your symptoms for a reaction to the food. In that way, we can identify which foods that you are react to.

Whereas lab testing only tests how certain parts of the immune system (such as IgG) respond to foods, an elimination diet paints the picture of how the body as a whole responds to the food. This is important as there may be other causes of a reaction other than just IgG antibody reactions.

Eight common foods that are often temporarily eliminated by someone suspecting food sensitivities are dairy products, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat and soy containing foods.

An elimination diet like this can be empowering but it is also restrictive, mentally challenging and time-consuming. An elimination diet, combined with IgG food reactivity lab-testing, provides the most complete view of food sensitivities. If a strict elimination diet is not possible for a person, then lab-testing alone is still a valuable option.

IgE – Allergic Reactions

In this article, I’m not going to go into detail around allergic IgE mediated, but I am going to focus on IgG food sensitivities. The difference between the two is IgE symptoms develop within a couple of minutes to one or two hours after eating a food and include symptoms such as hives, congestion or swelling of the throat. If you suspect a true allergic reaction to a food, please speak to your GP or contact me for further details on lab testing as I’m not going to focus on true allergies in this article. It is also possible to reduce the severity of IgE reactions, but not typically get rid of them, through nutritional support and Functional Medicine.

IgG Food Reactivity Lab-Testing

IgG antibodies tend to be associated with food sensitivities, and are produced from 3 to 72 hours after a food is eaten. At low levels, IgG antibodies are protective and their production is expected but at higher levels, they are associated with inflammation and typical IBS type symptoms. An IgG-mediated reaction to a food may not be noticed until more than 24 hours after eating a food, and remain in the body for weeks after a reaction is triggered, making identification of food sensitivities difficult without an elimination diet or lab testing.

There are many versions of IgG antibody testing to foods, and this diversity of testing can make choosing the right test confusing and overwhelming. Interpretation also benefits from professional help as the key to real improvement is not to only identify and remove trigger foods from the diet, but also support the gut and immune system so that it’s not so reactive. Our intention should always be to eat as varied and nutrient-rich diet as possible.

The food sensitivity test I recommend is by Dunwoody Labs. It is probably the most clinically relevant as it tests over 90 foods against a single blood sample for the production of IgG antibodies and also something call Compliment (Immune Complex containing C3d (IC-C3d)).  By measuring both IgG and IC-C3d simultaneously, we get a much clearer signal of activation of the immune system, giving much more accurate results than other IgG food tests that only measure IgG.

It is however important to note that some people, that have a severely impaired immune system, may not be capable of launching an immune response to trigger foods. In which case, IgG food sensitivity testing would be essentially useless.

How to Reduce Food Sensitivities

In the second article in this series (which will be coming in the next few weeks), I’ll take a deep dive into what you can do to reduce food sensitivities and improve your oral tolerance.

If you have any questions, I’m always happy to help so please get in touch. To know more about how you can work with me, you can find out more here.


Stephen Ward Headshot Image

FREE 20 INTRODUCTORY CONSULTATIONS NOW AVAILABLE – BOOK HERE

Stephen Ward (MSc) is trained in assessing the root cause of chronic health issues through Functional Medicine.

He uses nutrition, lifestyle changes, and nutraceuticals (targeted supplements) to help you achieve your goals and improve your health.

What is Leaky Gut? And 12 signs you have one…

Did you know our digestive system has two purposes?

Of course, it allows us to break down food into smaller and smaller particles to be absorbed into the bloodstream and be used by the body. Naturally, we need those nutrients to live!

But also, it blocks larger particles known as macromolecules from being absorbed into the body. These macromolecules include toxins, pathogens, and undigested foodstuffs. This unseen barrier is vital to our long term health and wellness.

Leaky gut, or increased intestinal permeability as it’s known academically, allows the uncontrolled passage of these macro-molecules into the body from the small intestine.

In the small intestine, the epithelial lining itself is only one cell thick. It functions like a cheesecloth with only small molecules intended to pass through the intestinal barrier. As food winds its way through the small intestine, it is broken down into smaller and smaller components until they are small enough to be absorbed through the cheesecloth.

Holes in a net

However, when there is inflammation in the intestine and increased intestinal permeability, larger macro-molecules, pass through the cheesecloth unchecked. It is as if the cheesecloth has tears in it which let the larger molecules through. This is bad news as the immune system recognises these molecules as undesirables and produces antibodies to these molecules, leading to inflammation, and the potential for a host of health issues.

The state of health or the state of disease is the combination between what we are – meaning what genetically makes us the way we’re engineered – and the environment that’s around us. And the gut is the point of entry in which these two elements meet

Alessio Fasano, MD

The gut lining and mucus layer work together

The good news is the epithelial lining is protected by a layer of mucus, known as the mucosal immune system (MALT). While the epithelial lining restricts access to the body of ‘troublesome’ macro-molecules and secretes antimicrobial substances, the mucus prevents unwanted organisms from sticking to the lining. The lining is where the good ‘good’ bacteria live, limiting the colonisation by unwanted organisms.

In healthy states, the MALT provides protection against pathogens but maintains tolerance against non-threating substances such as food molecules. In other words, the MALT should be smart enough to react to things that may be bad for us, but not react to other things which are harmless. Our microbiome plays a part in training our immune system to react in this way.

Luckily, there are dietary and lifestyle changes, as well as nutrients that can be taken to help repair this protective firewall and increase the diversity of our gut microbiome.

It is now recognized that the interface of the individual’s intestinal immune system with their gut microbiome has a critical effect on metabolism and immunity spanning the function of many organs and diseases including cancer, diabetes, arthritis, obesity, anxiety/depression, and autism.

Dr. J.Bland (Founder and PIONEER IN FUNCTIONAL MEDICINE)

How can I tell if I have leaky gut?

While there is testing that can be done for intestinal permeability, the truth is MOST people with a chronic health issue will have some degree of increased intestinal permeability.

And remember, you don’t have to have gut symptoms to have a leaky gut. Leaky gut can manifest as autoimmune conditions affecting the thyroid (Hashimoto’s) or joints (rheumatoid arthritis), mental illness, depression, skin problems like eczema or psoriasis and more.

12 signs you have leaky gut:

  1. Food sensitivities or intolerances – As food particles may enter the bloodstream through a leaky gut, the immune system of a person with increased intestinal permeability may react to a food (especially gluten and dairy). Leaky gut and allergies have been found to be linked.
  2. Poor Immune System Function: Including susceptibility to viruses and parasites
  3. IBS and bloating Particularly diarrhea-predominant IBS
  4. Candida, Parasites and Small Intestine Bacterial Overgrowth
  5. Inflammatory Bowel Disease
  6. Chronic Fatigue – Inflammatory compounds, called cytokines are associated with increased intestinal permeability and can lead to fatigue
  7. Auto-Immune Diseasesread more here including Hashimoto’s Thyroiditis
  8. Polycystic Ovary Syndrome – PCOS has been associated with increased zonulin, a biomarker of increased intestinal permeability
  9. Nutrient Malabsorption – This may be associated with fatigue
  10. Skin issues – such as psoriasis, acne, rosacea, or eczema
  11. Mood issues, Depression, Anxiety, and Mood Swings
  12. Brain Fog and Memory Issues

Now, the good news is intestinal permeability is completely reversible, and the mucosal firewall can be repaired. This may then improve health conditions outside of the gut so that you feel the difference.

But first, read the next article to find out how intestinal permeability is key to the development of an auto-immune disease. If are looking for the steps you need to heal your gut, you probably need to read this article.


Stephen Ward (MSc) is trained in assessing the root cause of your health issues and together, we can work this out.

Call 0491611043 or BOOK ONLINE.

Alternatively, send me a message and I’ll get back to you ..

Quit sugar: The effect of sugar on our guts

Do you find that when you are stressed or tired, you automatically seek out something sweet?  And then many of us find it difficult to stop eating sweet foods once we have started.

It is as if, we are biologically hard-wired to crave sugar.

In fact we are.

In Paleolithic times, that sweetness was probably hard to find and the calories were valuable, and so our bodies today do not know how plentiful sugar is in today’s society and we still have that craving.

It’s not your fault that you crave sugar, and it’s perfectly normal.

Sugar in Australia

Australia’s sugar intake has been described by experts as ‘alarming’ with the worst habits among children and adolescents. The 2011 Australian Health Survey of more than 8000 participants found 55% of people consumed more added sugars than recommended. The average American is eating somewhere between 130 and 152 pounds, or 58 to 69kg of sugar a year! 152 pounds of sugar equates to 52 teaspoons a day.

If we could see this amount of sugar laid out, I’m convinced we would immediately do something about it. But as it is hidden away in many foods, we simply do not realise how much we are eating.

Sugar and gut health

But is sugar particularly bad when it comes to the gut?

It sure is!

The microorganisms that live in our gut, that is yeasts, bacteria, protozoa, act in a similar way to a metabolic ‘organ’. Sugar changes the gut microbiota in a way that increases intestinal permeability, or ‘leaky gut‘.

It can particularly feed Candida (a type of yeast), and ‘bad’ bacteria that cause inflammation, and again, causing leaky gut. This allows larger molecules to come into contact with immune cells, which react with further inflammation. These molecules then pass into the blood, and are transported to the liver via the portal vein.

And so the microbiome and leaky gut have been reported to be involved in the development of chronic liver disease and portal hypertension (high blood pressure).

Leaky gut has also been associated with visceral fat (fat around the tummy), presumably as the body uses the fat cells to store the toxic macro-molecules that have entered into the bloodstream. So it seems, leaky gut can make you fat, and that’s not just from all the calories in all that sugar!

Because there is so much sugar in the typical diet, our blood sugar levels are soaring, and high blood sugar has also been shown to increase intestinal permeability directly, at least in mice. These sugar spikes trigger the centers in our brain associated with reward, pleasure, and seeking out the source of that feeling. Amazingly, these are the same areas of the brain that light up in people that are addicted to cocaine, heroin, and nicotine.

It’s not your fault that you crave sugar!

It’s clear that sugar has addictive properties and we need to put in the effort to de-normalize sugar, so it loses its group on us. We can then choose to eat it in small amounts, as a treat, and under our control 🙂. We may find that our energy is more even, our gut is healing, and we have lowered our type 2 diabetes risk.

Retrain your taste buds

You can retrain your taste buds, by eliminating all added sugar from your diet for four weeks

At the end of four weeks without added sugar, your taste buds will have adjusted, and you may find sweetened foods just too sweet for your new tastes. The tea you drank with two teaspoons of sugar, may now taste weird and kind of disgusting. Congratulations!You have now successfully de-normalized sugar!

Added sugar is any form of sugar or sugar alternative added to, or contained in, your food. This includes the raw sugar in your tea, coconut sugar, rice bran syrup, maple syrup, molasses, or agave syrup on your fruit. While there are some metabolic differences between the forms of sugar, your gut and its microbiome don’t discriminate between the type or source of the sugar, or whether it is refined or unrefined. It is all the same:

Sugar = Sugar = Sugar

At the end of four weeks without added sugar, you can introduce a little maple syrup or raw local honey if you want to…

Artificial sweeteners aren’t recommended either as they wreak havoc on the gut by altering the gut microbiota. Small amounts of stevia are probably the best option, although even that may cause gut irritation in some sensitive people.

What does the science tell us about gluten and leaky gut?

Catchy headlines poke fun at the gluten-free ‘fad’, and many GPs still do not believe non-celiac gluten sensitivity could be affecting their patients. But many people are finding that they feel better when they avoid gluten. So what does the research tell us?

In case you didn’t know, gluten is a family of proteins found in most cereals including wheat, rye, spelt, and barley. It gives dough a glue like consistency which holds it together. Gluten is not only found in obvious foods such as bread, pasta, and beer but also soy sauce, sweats, chips, hot dogs and battered fish!

Celiac Disease

In people with celiac disease, gliadin is a powerful trigger of zonulin release. Zonulin increases intestinal permeability by opening the tight junctions in the epithelial lining, and in people with celiac disease, an auto-immune response follows.  This is a serious condition, and full-blown celiac disease is associated with complete atrophy of the villi which line the small intestine and absorb your nutrients. If you suspect celiac disease, particularly if you have a family history of celiac disease, please speak to your GP about testing.

Non-Celiac Gluten Sensitivity

Whilst increased intestinal permeability in response to dietary gluten is most severe in those with celiac disease, zonulin, a marker for intestinal permeability, is also increased in people with what is called non-celiac gluten sensitivity (NCGS) and also irritable bowel syndrome with diarrhea.

NCGS is a term applied to people who experience symptoms in response to consumed to gluten consumption but do not have celiac disease. They may feel gastro-intestinal discomfort, fatigue or neurological symptoms. These people tend to improve on a gluten-free diet. Unfortunately, these people can be mocked for avoiding wheat and told that it’s all in their head.

But researchers have found that people with NCGS have increased intestinal permeability compared to healthy subjects. This should not be surprising as we know gliadin increases the release of zonulin, which can affect tight junctions. The opening of these tight junctions, our gateways. allows macromolecules to come into contact with our immune system and our bloodstream and explains why the group with NCGS also had a systemic immune activation on eating gluten.

Gluten increases Intestinal Permeability in All Human Tissue

In a 2015 study, researchers found tissue taken from the duodenum of humans became permeable, and there was increased inflammation when exposed to gliadin (i.e. leaky gut). As this study is in tissue taken from people rather than directly in people themselves, we have to be careful extrapolating the results. However, this backs up the experiences of many people .. they feel better when they don’t consume gluten.

In people with gluten sensitivity and NCGS, the damage did not clear after 36 hours, and what is most surprising, is that after five hours the tissue taken from ‘healthy’ people without celiac of NCGS, still had increased permeability.

Now, the epithelial lining of the small intestine is made up of the fastest growing cells in the body, creating a new lining every 3 to 7 days, and the gut lining would heal itself after exposure to gluten. But, if you have toast for breakfast, a sandwich for lunch, and pasta for dinner, it is never getting a chance to heal. Remember, I’m talking about people who aren’t celiac or don’t have NCGS here. If you consume gluten for breakfast, lunch, and dinner, your gut lining never has a chance to repair and you leaky gut will develop.

Researchers refer to this as the loss of oral tolerance. Now, your body can not deal with the toxins you are exposed to, and it may also start reacting to foods you didn’t react to both, as your immune system fights to defend itself. You have pathogenic intestinal permeability or a leaky gut and this can lead to inflammation in the body and autoimmunity.

Although lab tests do exist to look at your sensitivity to gluten, it’s widely accepted that an elimination diet is the best way to test for gluten intolerance. If you have a chronic health condition, it may be a good idea to remove gluten from your diet and see if that is of benefit. If you want to go further with the elimination diet, a Low FODMAP diet may be the next logical step to improve gut health.

The Leaky Gut / Auto Immunity Connection

This is part of a series on “leaky gut” (intestinal permeability). In the first, I talked about what leaky gut is and 11 signs that you have it.

It’s very common for people eating the Standard Australian Diet, or other Western diet, to struggle with gut function and autoimmunity. This does not mean that it’s “normal” and that we can do nothing about it!

Leaky gut is one of the root causes of many of today’s chronic diseases and has been called a “danger signal for autoimmune diseases”…

How Auto-Immunity begins

When intestinal permeability is increased beyond normal, macro-molecules enter the bloodstream. The immune system, which is always on guard for potential pathogens, is waiting for them! As it doesn’t recognise these macro-molecules, it raises the alarm and the body then makes antibodies to these macro-molecules. If those macro-molecules are gluten, your body makes antibodies to gluten. If it’s dairy, your body makes antibodies to dairy.

OK, so now I have a reaction to a particular food, that’s it right?

That’s just the beginning, unfortunately… As human tissue structure appears very similar to the targeted macro-molecule, components of the body’s immune system target one or more types of your own tissue e.g. the thyroid. This is known as molecular mimicry and results in human tissue being damaged as collateral damage, and the process of autoimmunity begins.

The tissue that is the target of the antibodies depends on that person’s weakest link. For instance, gluten cross-reacts with neurological tissue in some people, thyroid tissue in others, and so on. Remember though, the underlying process of auto-immunity is the same whether it is Hashimoto’s thyroiditis, rheumatoid arthritis, or pernicious anemia.

This process continues until the targeted tissue starts to lose function and you go to see the doctor and are then diagnosed with an auto-immune condition. But the actual process may have started years early when the body first started creating these antibodies to the macro-molecules and human tissue.

Dr. Alessio Fasano, the chair of pediatric gastroenterology at Massachuesetts General Hospital looks at Celiac disease as a model of auto-immune conditions; The three underlying factors these conditions share are:

Three causes of autoimmunity: Leaky Gut, Genetics, Environment

Less than 10% of those with the genetic disposition for the development of auto-immunity progress to a pre-disease state, illustrating the importance of other causal factors besides a person’s genetics. Leaky gut and environmental triggers, such as gluten, are two of these key factors. Indeed, research has show that increased intestinal permeability often precedes the development of auto-immune conditions.

Why monkeys don’t develop auto-immune diseases…

In 2000, researchers from the University of Maryland School of Medicine identified a protein, called zonulin, which opens gateways, or tight junctions, in the small intestine to let macromolecules into the bloodstream.

Mechanism of Intestinal Permeability

As is typical in the history of immunology, zonulin has been further clarified and renamed as haptoglobin 2 precursor.

“While apes, monkeys and chimpanzees do not have haptoglobin 2, 80 percent of human beings have it… Apes, monkeys and chimpanzees rarely develop autoimmune disorders. Human beings suffer from more than 70 different kinds of such conditions. We believe the presence of this pre-haptoglobin 2 is responsible for this difference between species.”


ALESSIO FASANO, MD

To heal your gut and repair leaky gut, you will need to follow a plan that includes steps to remove the cause of your issues, repair leaky gut, and then reseed your gut bacteria.


If you are ready to get your health and vitality back so you can lead a better life but need a little bit of help, I offer one-to-one consultation plans. I will help you get to the root cause of your gut issues, and address it with an effective personalised nutrition and lifestyle plan, that is manageable and sustainable, without nasty side effects.

Call 0491611043 or email info@fairfieldnutrition.com.au NOW!