What Are The Most Common Food Intolerance

What Are The Most Common Food Intolerance

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Many people confuse food allergies and food intolerance, which have some similarities, but there are distinct differences. As we already talked about food allergies, in this article we will discuss the difference between food allergies and food intolerance, first, and then we’ll see what are the most common food intolerance.

Main Differences Between Food Allergy And Food Intolerance

Food allergy is an immune system reaction that occurs soon after eating a certain food. It’s caused by your immune system wrongly recognizing some proteins in food as harmful. Your body then launches a range of protective measures, including releasing chemicals like histamine, which causes inflammation.

With a food intolerance, (also known as non-IgE mediated food hypersensitivity or non-allergic food hypersensitivity), your immune system isn’t responsible. Most of the time it’s a problem with digesting the food. Symptoms of food intolerance are usually less severe.

For example, being allergic to milk is different from not being able to digest it properly because of lactose intolerance.

* Causes

Food allergies can develop at birth or arise in adulthood. The cause of a food allergy comes from a weakened immune system where the body mistakes a food protein for an infectious threat.

Food intolerance is the opposite of a food allergy; the reaction is caused by food products that are non-proteins. Food intolerance is actually more common than food allergies, and causes the body to have difficulty digesting specific foods.

There are several causes of food intolerance. The most common factor is the absence of enzymes needed to digest foods which in turn will cause improper digestion. Almost all foods require enzymes to break them down. With a lack of appropriate enzymes, the digestive tract will be unable to break down foods and cause different symptoms.

* Reaction Time

Food allergy symptoms usually develop within a few minutes to two hours after eating the offending food.

Whereas, when you have a food intolerance, symptoms usually begin within a few hours of eating the food that you are intolerant to. Yet, symptoms can be delayed by up to 48 hours and last for hours or even days, making the offending food especially difficult to pinpoint.

* Symptoms

– Symptoms of food allergy include, among others, hives, swelling, itching, dizziness, even anaphylaxis.

– While symptoms of food intolerance vary, they most often involve the digestive system, skin and respiratory system.

Common symptoms include:

  • Diarrhoea
  • Bloating
  • Rashes
  • Headaches
  • Nausea
  • Fatigue
  • Abdominal pain
  • Runny nose
  • Reflux
  • Flushing of the skin

The main difference between the symptoms is that with food allergies, even a small intake of food will cause a reaction. On the other hand, if you are intolerant to specific foods, you won’t see any visible signs right away after you eat; larger amounts of the questionable food are needed before a reaction ensues. Symptoms of food intolerance take much longer to develop. One may not realize that there is a problem for a long period. If you are experiencing troubles but don’t know exactly what food(s) you are intolerant to, the best thing to do is to run intolerance test.

Intolerance Lab is the key to getting your life back

Most Common Food Intolerances

1. Dairy Products

For those who are sensitive, dairy products can cause gastrointestinal and/or respiratory symptoms, as well as skin reactions. There are two reasons why this happens:

  • Many people are lactose intolerant. This means that they lack enough lactose, a digestive enzyme necessary to digest the sugar lactose that’s present in dairy products.
  • Dairy products contain a protein called casein. Casein may be hard to digest and can result in allergy reactions and inflammation within the digestive system.

If you choose to eliminate dairy products, then you would exclude milk, cheese, butter, yoghurt, and ice cream. This list includes any product derived from the milk of cows, goats, and sheep.

2. Eggs

There are proteins within eggs that cause unwanted symptoms for some people. Egg whites have more of these proteins, but if you’re going to include eggs on your elimination diet, it’s best to avoid them completely. Once you’ve eliminated eggs from your diet for a period, you can challenge the egg yolks and egg whites separately to assess for any reactivity.


3. Gluten

Gluten is a protein found in barley, wheat, and rye. Several conditions related to gluten, including celiac disease, non-celiac gluten sensitivity and wheat allergy.

Celiac disease involves an immune response, which is why it is classified as an autoimmune disease. So, if you have celiac disease you must totally avoid gluten.

Wheat allergies are often confused with celiac disease due to their similar symptoms.

They differ in that wheat allergies generate an allergy-producing antibody to proteins in wheat, while celiac disease is caused by an abnormal immune reaction to gluten in particular.

However, many people experience unpleasant symptoms even when they test negative for celiac disease or a wheat allergy.

This is known as non-celiac gluten sensitivity, a milder form of gluten intolerance that has been estimated to impact anywhere from 0.5 to 13% of the population.

Gluten Intolerance Symptoms
Symptoms of non-celiac gluten sensitivity:

  • Bloating
  • Abdominal pain
  • Diarrhoea or constipation
  • Headaches
  • Fatigue
  • Joint pain
  • Skin rash
  • Depression or anxiety
  • Anaemia

Both celiac disease and non-celiac gluten sensitivity are managed with a gluten-free diet.

It involves adhering to a diet free from foods and products that contain gluten, including:

  • Bread
  • Pasta
  • Cereals
  • Beer
  • Baked goods
  • Crackers
  • Sauces, dressing and gravies, especially soy sauce

4. Peanuts

Peanuts are definitely on the list of top food allergens. Even if you don’t have an allergic reaction to peanuts, there remains the possibility that you’re sensitive to them. Peanuts are not true nuts but are actually classified as legumes. Signs of a peanut sensitivity include respiratory or digestive symptoms.

5. Caffeine

Caffeine is a bitter chemical that is found in a wide variety of beverages, including coffee, soda, tea and energy drinks.

It’s a stimulant, meaning it reduces fatigue and increases alertness when consumed. It does so by blocking receptors for adenosine, a neurotransmitter that regulates the sleep-wake cycle and causes drowsiness.

Most adults can safely consume up to 400 mg of caffeine a day without any side effects. This is the amount of caffeine in about four cups of coffee.

However, some people are more sensitive to caffeine and experience reactions even after consuming a small amount.

This hypersensitivity to caffeine has been linked to genetics, as well as a decreased ability to metabolize and excrete caffeine.

A caffeine sensitivity is different from a caffeine allergy, which involves the immune system

People with a hypersensitivity to caffeine may experience the following symptoms:

  • Rapid heartbeat
  • Anxiety
  • Jitters
  • Insomnia
  • Nervousness
  • Restlessness

People with a sensitivity to caffeine should minimize their intake by avoiding foods and beverages that contain caffeine, including coffee, soda, energy drinks, tea and chocolate.

6. Amines

Amines are produced by bacteria during food storage and fermentation and found in a wide variety of foods. Though there are many types of amines, histamine is most frequently associated with food-related intolerance.

In people without an intolerance, histamine is easily metabolized and excreted. However, some people are not able to break down histamine properly, causing it to build up in the body.

The most common reason for histamine intolerance is impaired function of the enzymes responsible for breaking down histamine — diamine oxidase and N-methyltransferase.

Symptoms of histamine intolerance include:

  • Flushing of the skin
  • Headaches
  • Hives
  • Itching
  • Anxiety
  • Stomach cramps
  • Diarrhoea
  • Low blood pressure

People with an intolerance to histamine should avoid foods high in this natural chemical, including:

  • Fermented foods
  • Cured meats
  • Dried fruits
  • Citrus fruits
  • Avocados
  • Aged cheeses
  • Smoked fish
  • Vinegar
  • Soured foods like buttermilk
  • Fermented alcoholic beverages like beer and wine

Now Discover Your Intolerances


7. Beef, Pork, and Lamb

Some people report a sensitivity to animal meats. Theoretically, this may be due to the way that most livestock is now reared. Conventionally raised livestock are given corn and soy as primary feed sources, as opposed to grazing on grasses in a pasture. In addition, these animals are also given hormones and antibiotics, all of which have the potential to affect the meat that you’re eating. If you think that these meats are a problem for you, you could try looking for pasture-raised animals and performing a food challenge based on animals that were properly raised and fed. In addition to the fact that you will be eating the meat of healthier animals, there is some speculation that meat from properly raised animals contains components that are good for the health of your gut.

8. Salicylates

Salicylates are natural chemicals that are produced by plants as a defence against environmental stressors like insects and disease.

Salicylates have anti-inflammatory properties. In fact, foods rich in these compounds have been shown to protect against certain diseases like colorectal cancer.

These natural chemicals are found in a wide range of foods, including fruits, vegetables, teas, coffee, spices, nuts and honey.

Aside from being a natural component of many foods, salicylates are often used as a food preservative and may be found in medications.

While excessive amounts of salicylates can cause health problems, most people have no problem consuming normal amounts of salicylates found in foods.

However, some people are extremely sensitive to these compounds and develop adverse reactions when they consume even small amounts.

Symptoms of salicylate intolerance include:

  • Stuffy nose
  • Sinus infections
  • Nasal and sinus polyps
  • Asthma
  • Diarrhoea
  • Gut inflammation (colitis)
  • Hives

While completely removing salicylates from the diet is impossible, those with a salicylate intolerance should avoid foods high in salicylates like spices, coffee, raisins and oranges, as well as cosmetics and medications that contain salicylates.


FODMAPs is an abbreviation that stands for fermentable oligo-, di-, mono-saccharides and polyols.

They are a group of short-chain carbohydrates found naturally in many foods that can cause digestive distress. FODMAPs are poorly absorbed in the small intestine and travel to the large intestine, where they are used as fuel for the gut bacteria there. The bacteria break down or “ferment” the FODMAPs, which produces gas and causes bloating and discomfort.

These carbohydrates also have osmotic properties, meaning they draw water into the digestive system, causing diarrhoea and discomfort.

Symptoms of a FODMAP intolerance include:

  • Bloating
  • Diarrhoea
  • Gas
  • Abdominal pain
  • Constipation

FODMAP intolerance is very common in people with irritable bowel syndrome, or IBS.

In fact, up to 86% of people diagnosed with IBS experience a reduction in digestive symptoms when following a low-FODMAP diet.

There are many foods high in FODMAPs, including:

  • Apples
  • Soft cheeses
  • Honey
  • Milk
  • Artichokes
  • Bread
  • Beans
  • Lentils
  • Beer

10. Sulfites

Sulfites are chemicals that are primarily used as preservatives in foods, drinks and some medications. They can also be found naturally in some foods like grapes and aged cheeses. Sulfites are added to foods like dried fruit to delay browning and wine to prevent spoilage caused by bacteria.

Most people can tolerate the sulfites found in foods and beverages, but some people are sensitive to these chemicals.

Sulfite sensitivity is most common in people with asthma, though people without asthma can be intolerant to sulfites as well.

Common symptoms of sulfite sensitivity include:

  • Hives
  • Swelling of the skin
  • Stuffy nose
  • Hypotension
  • Flushing
  • Diarrhoea
  • Wheezing
  • Coughing

Sulfites can even cause airway constriction in asthmatic patients with sulfite sensitivity, and, in severe cases, it can lead to life-threatening reactions.

The Food and Drug Administration (FDA) mandates that the use of sulfites must be declared on the label of any food that contains sulfites or where sulfites were used during the processing of food.

Examples of foods that may contain sulfites include:

  • Dried fruit
  • Wine
  • Apple cider
  • Canned vegetables
  • Pickled foods
  • Condiments
  • Potato chips
  • Beer
  • Tea
  • Baked goods

11. Corn

Unfortunately, today’s corn is not the corn that our ancestors ate. In research studies, corn has shown up as one of the top foods to contribute to irritable bowel syndrome (IBS) symptoms. The tricky thing about eliminating corn is that it’s now a component of so many processed foods in the form of high fructose corn syrup. You’ll need to read labels carefully.

12. Soy

Many adults attribute irritable bowel syndrome (IBS) symptoms to eating soy-based products. Like corn, soy and its derivatives are now found in a good deal of food products. Therefore, just like corn, to avoid soy, you must be very careful about reading food labels.

These are the 12 most common food intolerance. There are a good deal of food intolerances, and if you can’t determine which food(s) make problems for you (honestly, it’s very hard in most cases) you should do a lab test.

Thank you for reading this article. If you have any question, or want to leave a comment – impression, suggestion, your thoughts, experience… please do so in the comment section below, and I’ll be happy to help you out.

2 thoughts on “What Are The Most Common Food Intolerance

  1. Tanya, this post is packed with useful information.

    Pre-internet days which doesn’t seem too long ago, we were just eating anything and didn’t think too much about the consequences and when they happened we relied on our doctors.

    It’s only when we get to certain ages that we decide to “try” and change our lifestyles which in many cases is a little too late. The damage so to speak as already been done.

    I wasn’t aware of what you mentioned about corn, in fact, I wasn’t aware of many things in your post.

    Thank you for educating me and a great post too.

    1. Thank you Mick, I did really try to explain, compare food allergies and intolerances and present the most common food intolerances. I’m glad you found this article to be informative and comprehensive. New knowledge helps us to better understand things and react to them accordingly. Let me know if you have any questions.
      All the best

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