Food intolerance is extremely common and disruptive to daily life. 

As a healthcare practitioner, I meet so many people (for whatever reason) that have food intolerances which are contributing to their inflammation levels and health issues. 

So, if you worry about what to eat and dread eating out in case you consume something that triggers you, you’re probably fed up trying to figure out those culprit foods that your body is reacting to. 

What Is a Food Intolerance? 

A food intolerance is when your body can’t properly break down or process a certain food or ingredient. 

Gluten intolerance for example is the result of an enzyme deficiency that prevents the body from properly breaking down gluten, a protein found in wheat, barley and rye.

A food intolerance can also be referred to as a food sensitivity.

The American Academy of Allergy Asthma & Immunology states that “A food sensitivity occurs when a person has difficulty digesting a particular food.” 

Symptoms of Food Sensitivity

If you suffer from irritable bowel syndrome and experience things like gas, bloating, constipation, diarrhea or nausea you have probably wondered whether your symptoms are food related. 

Even if you don’t have any signs of poor digestion after a meal, there are plenty of systemic indications that the body could be struggling to digest certain foods. 

There are so many things that could be symptoms of dealing with food related issues, and then there are others you would never associate as diet-related. 

Here is a list of the most common symptoms. This is not an exhaustive list and you may experience one or all of your symptoms with any given food you’re intolerant to.

• Abdominal pain
• Diarrhea
• Constipation
• Dark circles or bags under the eyes
• Gas and bloating
• Skin problems e.g. eczema, acne, psoriasis
• Headaches or migraines
• Heartburn
• Nausea
• Anxiety, depression or low mood
• Fatigue and lethargy 
• Brain fog and trouble concentrating 
• Joint aches & pains 
• Low immunity - picking up colds, viruses and bugs easily
• Sleep problems
• Sinus congestion
• Weight loss resistance

Remember symptoms of food intolerances vary from person to person.

But anecdotal studies show that more than 25% of the population have food sensitivities and feel better when they avoid certain foods.

The Difference Between a Food Allergy and a Food Intolerance 

It’s easy to get confused between what’s a food allergy and what’s a food intolerance or sensitivity. 

Very often the terms are used interchangeably, which makes matters worse.  So, let’s distinguish the key differences between the two.

Food Allergy

With a true food allergy, the immune system produces a specific kind of antibody (known as IgE), in the presence of an allergen food it perceives as a threat. This triggers an allergic reaction. 

Food allergies are much easier to identify than food intolerances because reactions are more immediate, severe and tend to be permanent. 

Food Intolerance

A food intolerance is generally much harder to pin down.

Food intolerances can occur at any age, symptoms are often vague and appear unrelated because reactions don’t necessarily happen immediately after eating the problematic food.

Symptoms may appear within hours after eating, but can even be days. 

The good news is, food intolerances can in most cases be remedied when the gut is healed.

And in my experience food intolerances are often a result of something else in the body that needs addressing.

What Causes a Food Intolerance?

A food intolerance can occur as a result of:

• a lack of necessary enzymes in your digestive system to break down certain foods 
• your digestive system struggling to keep up with the demands of your diet or other GI / digestive function issues
• a sensitivity to naturally occurring chemicals in foods like histamine, lactose, fodmaps or chemical additives
• certain gastrointestinal conditions can also make some people more prone to food intolerances e.g celiac disease, crohn’s disease and ulcerative colitis.
• a leaky gut (intestinal permeability) due to an imbalance of gut microbiota or toxic load like infections in the gut. 

Leaky Gut

With a leaky gut, food particles seep into the bloodstream and are flagged as a threat.

The immune system then creates an inflammatory response which can be gut specific as well as systemic.

Yes - a leaky gut in itself can trigger a lot of frustrating and unpleasant symptoms within the body. 

Bioindividuality & Food Intolerance

Food intolerances are a classic example of bio-individuality.

Bio-individuality is the concept that there’s no one-size-fits-all approach to health and nutrition. And that we’re all unique in our biological makeup and requirements. 

The same foods that might be problematic for one person can be healing for another.

Everything from your genetics, to your gut microbiome, to your hormones and to your lifestyle can influence how you react to various foods.

Food tolerance level can also depend on what else is going on in the gut and the rest of the body at the time of eating. 

For instance, if your lifestyle revolves around eating on the go, as a result the stressed state your body is in will equate to a lack of or a reduction of necessary digestive enzymes to break down your food properly.  

How To Test For a Food Intolerance

Assessments, which tell you which foods are triggering an inflammatory reaction in your body, are very popular and there are several ways in which you can in theory determine what foods you’re intolerant or sensitive to.

Here are some of the most common testing methods.

Biofeedback Testing Methods 

Biofeedback testing involves using techniques that involve receiving physiological state information back from the body and in this case - food sensitivity to specific foods.  

Pulse Testing

The pulse testing method measures the stress response caused by foods based on the increase in your heart rate.

Problematic foods activate the sympathetic part of the autonomic nervous system, signaling a fight or flight response in the body which increases blood pressure and heart rate. 

Measuring your pulse rate when you’re exposed to certain foods can indicate whether they’ve activated this stress response.

Muscle Response Testing

Muscle weakness is thought to indicate that a food is problematic. This type of testing therefore assesses changes in muscle strength when a person is exposed to a certain food. 

The treatment approach once a food sensitivity is identified works to eliminate the body's inflammatory reaction by reprogramming the brain’s negative responses towards the food through desensitisation.

This method is not generally accepted as an accurate test for food sensitivities.

Using these kind of biofeedback practices to test for food sensitivities can be hard to do.

It can be challenging to pulse or muscle test all potential trigger foods and identify the foods that could be causing your symptoms on an ongoing basis.

Hence the speculation around their efficacy and accuracy.  

Elimination Diets

One of the most reliable ways to find out if you have a food intolerance is to embark on an elimination diet. 

An elimination diet typically involves removing a specific food or group of foods from your diet for a period of time to see how your symptoms (such as bloating, constipation, diarrhea or anxiety) might change.

The kind of foods eliminated are those considered to be more allergenic or inflammatory and include foods like gluten, dairy, eggs, soy, corn, grains, nuts, shellfish and legumes. 

Once these foods have been removed from the diet for the elimination period, you slowly reintroduce each food one at a time and monitor your reaction.

Because of the lengthy process involved with an elimination diet, doing it properly will take more time, effort and commitment compared to other testing methods. 

Hair Tests

Strictly not a biofeedback testing method but a bioresonance one - hair tests claim to determine your sensitivity to hundreds of foods by assessing the “bioresonance” of your hair.

This involves measuring the “energetic wavelengths” coming from your body.

Bioresonance  is based on the idea that your cells and organs emit altered electromagnetic waves with problematic foods. 

To-date, there’s no credible scientific evidence that bioresonance has a role in identifying food intolerances. 

Immunoglobulin (or Antibody) Blood Testing

IgG, IgA and IgM are the antibodies triggered in food sensitivities.

Measuring these levels gives you more clarity on your immune response to hundreds of foods. 

Most antibody tests only measure IgG responses though. So, I prefer those tests that either measure IgG and IgA, or all of the four subtypes of food-specific IgG (1-4) compared to some which test only for IgG4.

This is important as it ensures all of the different food-specific IgG reactions are detected.

Taking an IgG food antibody assessment can help you quickly and easily decide which foods to prioritise in eliminating them from your body. 

All IgG tests require a blood sample since IgG is released in the bloodstream.

Most tests just involve a finger prick for sample collection.

The higher the IgG levels against the individual foods tested, the higher the potential for a food intolerance. 

Test results will give each tested food a “score”. This score refers to the blood’s IgG levels in reaction to that food, often ranked numerically as well as in “level of reaction” categories as follows - no, mild, moderate and high. 

Reducing Inflammatory Food Burden On Your Body

Once you have identified any food intolerances you will want to avoid these foods for at least 21 days, sometimes much longer.  

You may be able to reintroduce more foods once your gut is healed and your immune system has calmed down. 

But in the meantime, continuing to consume foods that your body recognises as inflammatory will inevitably lead to increased gut permeability and worsening symptoms.

Final Tips on Treating Food Intolerances 

It’s important to make sure that your diet is nutritionally balanced before making any radical changes to your eating habits. 

Food sensitivity tests might be a useful or interesting experiment. But the results from those tests shouldn't be used on their own to make major dietary decisions. 

If you'd like to identify your food intolerances whether it’s via an elimination diet, or another testing method, it's worth working with a healthcare practitioner, like myself for guidance on this and how to reduce your symptoms - while helping you get to and tackle the “root cause” problem(s).  

 

If you found this post helpful and are looking for more ways to elevate your health, be sure to check out all of the resources available on my blog, and in my newsletter (just sign up in the form at the bottom of this page to subscribe).