Let’s talk about food allergies and food sensitivities because it is a hugely misunderstood topic 🙂
Reader’s summary / goals of this article:
- Remove your confusion about food allergies and sensitivites
- Explain different ways your body can react to foods
- Describe how food “reactions” make you feel unwell and drain your vitality
- Explain how you can identify food reactions in your body and quickly transform your symptoms into vitality
Accompanying this article is a great case study of how a family of four transformed their health using the kind of food allergy testing that many doctors “poo-poo”.
Confusion about food reactions
As the diagram shows, food is one of the most powerful influences on the way you look, feel and think.
[Thanks to Cyrex Labs for the image]
Food has the power to drastically improve your body and mind, but at the same time, there is potential for food to make you very ill.
But it’s confusing because a food (or even a vitamin or mineral, for that matter) which works well for one person may be extremely toxic and damaging to another.
Universally “bad foods”
Some foods – processed grains, sugars and vegetable oils – are plain bad for all humans, especially if they are eaten excessively.
It doesn’t really matter who you are, if you eat too many poor quality foods it is likely that your health will begin to suffer at some point.
In addition to the universally “bad” foods, each of us has the potential to react adversely to seemingly innocuous foods that most people tolerate just fine.
In 10 years of being a functional medicine practitioner in the UK, I’ve worked with clients whose lives were being utterly ruined by foods that you would find in any best-selling healthy cookbook.
Bananas, oranges, beef, beets, kale, spinach, eggs and several types of berry have all caused severe problems in individual cases.
Let’s look at why some of these adverse reactions happen, and why it’s so darned confusing.
Why food allergy is a confusing topic
There are several different ways your body’s immune system can “react” to food, including cytokine, IgA, IgE and IgG mediated reactions. These are discussed below.
Other food-related problems are not caused by the immune system so much. Instead, they stem from an inability to digest certain foods or substances (e.g. lactose intolerance).
It is these differences that lead to confusion.
Importantly, a single allergy test or functional medicine lab test cannot identify all the different adverse responses humans have to food because each test only looks for one kind of reaction.
If you have a food allergy test with your doctor that says you’re “negative” and not reacting to any foods, the result may be very misleading because only one type (of several different reaction types) was actually tested
Trusting that your food allergy lab test was 100% accurate, you carry on eating the very foods that are harming you.
But you may not be reacting to foods in a way that your test was unable to identify.
What is a food allergy?
To keep things simple, let’s define food allergies as the type of response that leads to immediate, obvious symptoms.
These allergies are caused by rapid onset immune responses to foods, which lead to obvious allergic symptoms.
Typical symptoms triggered by these kinds of responses include:
- Closing of the throat
- Wheezing and difficulty breathing
- Red skin
- Hives and rashes
This kind of reaction involves a subset of your immune system called immunoglobulin-E, or IgE, and involves mast cells and histamine release.
It is the same sub-component of the immune system that is responsible for hay fever and grass allergies to pet allergies, etc.
In serious cases, it’s this reaction that leads to anaphylaxis from time-to-time in the unlucky person who has a severe peanut, strawberry or seafood allergy.
IgE food allergy tests
A doctor can diagnose food allergies using a finger prick test, or you can have the test done by a private laboratory.
Tests may or may not be beneficial because you’ll most likely know if you have an IgE food allergy. Because symptoms develop quickly, it’s usually easy to identify the offending food or foods.
However, IgE allergies can be more subtle and do not always cause obvious symptoms. They can impact your health, body and mind without creating serious allergy symptoms.
For instance, I worked with a client in Australia who we found to have a corn allergy. The symptoms weren’t clear or obvious, but he felt much better on a daily basis when he omitted corn from his diet.
I would certainly consider using an IgE test to foods and environmental substances like grasses, pollen, cat dander, and others in children who were not responding to diet changes that would usually bring symptom improvement.
What are delayed food sensitivities?
I am going to define food sensitivity as a delayed reaction to food, which we will call delayed food sensitivity.
In this type of reaction, the symptoms take longer to develop after the offending food has been eaten.
In fact, they can kick in after 24 to 48 hours of eating the offending food.
A different part of the immune system contributes to these kinds of reaction, namely immunoglobulin-G, or IgG.
In the blood, food particles known as antigens bind with IgG antibodies to form what we call antigen-antibody clusters.
As these clusters grow in size, they can get wedged or embedded s in tissues, where they cause inflammation.
This inflammation can trigger many different symptoms. In fact, IgG food sensitivities may cause or contribute to the following uncomfortable health problems:
- Bloating and digestive pain
- Constipation or diarrhoea
- Low energy
- Mood problems
- Muscle pain
- Joint and arthritic pains
- Skin problems, including eczema, dermatitis, acne
- Difficulty sleeping
- Brain fog
- Behavioural symptoms like ADD and ADHD
Still confused? Hopefully this table will help (courtesy of Cambridge Nutritional Sciences):
IgG food sensitivities can cause widespread, chronic symptoms
None of the Seven Areas of Health are left untouched by IgG reactions, which can affect digestion, energy, mood, sex drive, skin, muscles and joints, weight, body composition, sleep and more.
IgG food sensitivity testing is reasonably well established in the scientific literature and I have seen some excellent improvements in my clients’ health when we found their main IgG-reactive foods and eliminated them for 60-days.
When you find out which foods you are reacting to, you can immediately remove them from your diet and potentially feel better quite quickly.
IgG food sensitivities – caution
There are three notes of caution with IgG food sensitivities:
First, you will see them called IgG allergies by some people, which is fine. I am only using the term “sensitivity” to keep IgG reactions separate from the IgE responses discussed above.
Second, IgG food sensitivitie are often the result of a damaged gut. In fact, the more IgG food sensitivities you have, usually the more damaged your gut will be.
Factors like stress, gluten, toxins, bacterial overgrowth, Candida, parasites and even exercise, can damage your stomach and intestinal barrier, causing increased intestinal permeability, or “leaky gut.”
When this happens, food particles (known as “antigens”) can leak into the blood stream in a relatively undigested state.
When these antigens enter your blood in an unrecognized form, your immune system mounts a response to them, which is what you see on the IgG food sensitivity test.
A high number of IgG food sensitivities usually means you need to work on repairing your digestive lining as well as just avoiding the foods.
Third, you will see some authors and practitioners claiming that IgG testing is a waste of time.
I strongly disagree.
Some of my clients have improved very rapidly as a result of avoiding foods shown to be highly reactive in their IgG testing.
Great Plains Laboratory has a finger-prick blood test kit that enables 93 foods to be checked without needing to leave the comfort of your home.
This is the test we typically use with our clients. Its simplicity is attractive – no blood draw is needed, which makes it great for busy lifestyles and also for kids.
This test also checks for IgG Candida antibodies, indicating problems with overgrowth in the digestive or genitourinary tracts.
However you must not rely on this test to solve all your problems! It’s still very important to consider all aspects of your diet, lifestyle digestion, detoxification and hormonal health.
What is food intolerance?
Food intolerances are different from IgE and IgG food reactions because they do not involve the immune system.
You may have heard of lactose intolerance and fructose intolerance?
Well, these conditions are the result of an inability to digest food components, which doesn’t involve an immune system reaction.
Lactose is a sugar found in milk, and fructose is a sugar found in fruit and vegetables (and their juices).
An inability to digest these sugars is usually the result of damage sustained by the digestive system by other factors such as stress, thyroid and adrenal problems, SIBO, H. pylori, gluten and so forth.
If you can’t digest these sugars properly they end up being fermented by gut bacteria, which leads to an accumulation of gas and resultant symptoms such as bloating, gas, pain, cramping and loose stools or diarrhoea.
Food intolerance and IgG sensitivities are not necessarily lifelong
Contrary to popular belief, many food reactions do not have to be endured for life. They can often be improved or even completely resolved by healing the gut and normalising the body’s nutrient status and hormone function.
Gluten sensitivity and coeliac disease (discussed separately), Candida, SIBO and parasites like Giardia can all lead to lactose and fructose intolerance.
Low stomach acid, pancreatic insufficiency, along with poor liver and gallbladder function can also contribute to these problems.
An underactive thyroid, adrenal problems and nutritional depletion can contribute to food sensitivities and intolerance.
This is why whenever we begin working with clients, we try to gather as much data as possible about how their body is working.
Doing so enables us to quickly get to the root or core of the problem so we can fix it faster.
Other types of adverse food reactions
A number of other important food issues are discussed elsewhere in this website, and also in my online Digestive Reset Plan.
- Gluten sensitivity and coeliac disease (a huge topic!)
- Sulphur and sulphite
It’s not easy to navigate your way through all this complex information, but the end result is well worth it.
Would you like some help?
High quality food sensitivity testing (perhaps along with metabolic typing) is the fastest and most effective way for you to customize your diet.
It removes confusion, puts control back in your hands and enables you to choose foods based on your individual requirements.
We offer home IgG food sensitivity tests, which we can ship right to your door.
The package comes with a full interpretation, case review and consultation to make sure you completely understand your results and what action steps you need to take.
If lab testing isn’t feasible for you, I strongly recommend you join our growing Digestive Reset Plan Community, which you can learn about here.
Please feel free to email with questions, or ask them on the weekly support calls and forum!
As always, we are here to make things as easy as possible for you.