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The Most Common Food Intolerances

The Most Common Food Intolerances

8th Jan 2024

Food Intolerances and Sensitivity

Overview

What is a Food Intolerance?

It’s thought that up to 20 per cent of the world’s population might have a food intolerance.

Food intolerances affect your digestive system, where your body cannot break down certain foods.

You might experience food intolerance symptoms such as gas, bloating, diarrhoea, abdominal pain, headaches or migraines, heartburn, nausea and an upset stomach, and while they’re not life-threatening, they can be unpleasant. Symptoms often occur within a few hours, sometimes up to 48 hours, after eating the food as it has to make its way through the digestive tract.

You might even be able to eat small amounts of the offending food without trouble and you may also be able to prevent reactions.

Is there a difference between food sensitivity and food intolerance? These two terms are interchangeable as they mean the same thing. A food intolerance means your gut is sensitive to certain foods and can’t tolerate them.

What is a Food Allergy?

Food allergies and intolerances are not the same thing.

A food allergy affects the immune system and occurs when the immune system mistakes a protein or other ingredient in food as a threat. The immune system then releases antibodies (proteins), called immunoglobulin E (IgE) to fight the threat.

This causes an allergic reaction, such as hives, swelling, shortness of breath or wheezing. Rather than hours like a food intolerance, these symptoms occur within minutes of consuming even a small amount of the food. Some allergies are more severe, causing a life-threatening reaction called anaphylaxis, which, without an epinephrine treatment, can be fatal.

Types of Common Food Intolerances

Lactose Intolerance

This is a condition where humans cannot digest foods containing lactose, resulting in uncomfortable digestive symptoms. It’s the most common food intolerance and it occurs when the body doesn’t make enough lactase enzymes to break down lactose, a sugar.

Symptoms of lactose intolerance include abdominal pain, bloating, diarrhoea, gas and nausea. Lactose is found in foods such as skim milk, whole milk, goat's milk, cultured buttermilk, powdered milk, cooking cream and cultured fermented milk.

Gluten Intolerance

Gluten is a protein found in the wheat plant and some other grains, like barley, rye and triticale. Gluten intolerance is often referred to as coeliac disease, a condition where the immune system attacks its own tissue when gluten is consumed, damaging the gut and small intestines and making people unable to absorb nutrients from foods; however, they’re not the same thing. You can have non-coeliac gluten sensitivity where your body just has a harder time digesting gluten.

Some individuals could also have a wheat allergy, which is often confused with coeliac disease due to their similar symptoms. Symptoms of gluten intolerance include bloating, abdominal pain, diarrhoea or constipation, headaches, fatigue, joint pain, skin rash, depression or anxiety or anaemia.

Gluten is found in foods such as pastry, pasta, bread, biscuits, breakfast cereals, beer and certain sauces, like soy sauce.

Caffeine Intolerance

Caffeine is a mild stimulant in the central nervous system that quickly boosts alertness and energy levels. Caffeine stimulates the heart, increases blood flow and increases blood pressure temporarily, particularly in those who don’t usually consume it.

Caffeine intolerance and hypersensitivity have been linked to genetics, as well as a decreased ability to metabolise and remove caffeine from the body.

Once again, a caffeine intolerance is different from a caffeine allergy, which affects the immune system. Caffeine sensitivity symptoms include a rapid heartbeat, anxiety, jitters, insomnia, nervousness and restlessness.

The daily recommended intake of caffeine is less than 400mg. It’s found in foods such as coffee, instant coffee, a small amount in decaffeinated coffee, espresso, tea, soda, energy drinks and dark chocolate.

Histamine Intolerance

Amines are produced by bacteria during food storage and fermentation, with histamines being the most common that are associated with food-related intolerances. These are naturally occurring chemicals, and some individuals don’t make enough diamine oxidase enzymes to break them down, causing an intolerance.

Symptoms of histamine intolerance include flushing of the skin, headaches, hives, itching, anxiety, stomach cramps, diarrhoea and low blood pressure.

Histamines are found in foods such as fermented foods, cured meats, dried fruits, citrus fruits, aged cheese, smoked fish, vinegar, soured foods, pineapples, bananas, avocados, chocolate, beer, red wine and some white wines.

Salt Sensitivity

Table salt, or sodium, is a mineral needed for the body to ensure the proper function of nerves and muscles, and it helps to keep the right balance of fluids in the body. Salt sensitivity refers to the acute blood pressure change in mean blood pressure corresponding to a decrease or increase of sodium intake.

The daily recommended intake of salt is 1000–1500mg. It’s found in foods such as white bread, boneless, skinless chicken breast and fresh tomatoes.

Alcohol Sensitivity

Alcohol is a psychoactive substance with dependence-producing properties.

The amount of alcohol in drinks varies, even with the same serving amount. For example, beer often has 4–8 per cent alcohol by volume, while wine can have 14–16 per cent and spirits can have 36–50 per cent of alcohol by volume.

Salicylate Intolerance

These are natural chemicals produced by plants as a defence against environmental stresses like insects and diseases. They also have anti-inflammatory properties that may help protect against certain diseases.

Some symptoms of salicylate intolerance include a stuffy nose, sinus infections, nasal and sinus polyps, asthma, diarrhoea, gut inflammation and hives. Salicylates are found in foods like fruits, vegetables, teas, coffee, spices, nuts and honey. They’re often also used as a food preservative and may be found in medications.

FODMAP Intolerance

This stands for fermentable oligo-, di-, mono-saccharides and polyols, and they’re a group of short-chain carbohydrates found in foods that often cause digestive issues. They’re poorly absorbed in the small intestine and instead move to the large intestine, where they’re used as fuel for our gut bacteria, which break FODMAPs down, producing gas that causes bloating and discomfort. They also draw water into the digestive system, causing diarrhoea and discomfort.

Symptoms of a FODMAP intolerance include bloating, diarrhoea, gas, abdominal pain and constipation.

Those with irritable bowel syndrome (IBS) often have FODMAP intolerances, hence why you often hear you should be following a low-FODMAP diet when you have IBS. Up to 86 per cent of people with IBS see reduced symptoms when they do.

Fructose is a type of FODMAP, with some people having fructose malabsorption and intolerance, where fructose isn’t well absorbed into the blood.

Foods high in FODMAPS include apples, honey, soft cheeses, milk, artichokes, bread, beans, lentils and beer.

Other common food intolerances:

  • Sulphites
  • Aspartame
  • Eggs
  • MSP
  • Food colourings
  • Yeast
  • Sugar alcohols

What Causes Food Intolerances?

Is a food intolerance a chemical reaction? Yes. People with food intolerances don’t often make enough of a particular enzyme that their digestive system needs to break down that particular food. The intolerance is a chemical reaction that some people have after eating or drinking certain foods.

It’s not fully known why some people develop food intolerances, however, certain gastrointestinal conditions may make you more susceptible, like coeliac disease and inflammatory bowel disease (IBD).

Why do I have so many food sensitivities? Some people are simply born with fewer enzymes to break down particular foods. Some people develop food intolerances as they get older, such as sudden food intolerance in adults, which can be a sign your body is compromised by an infection or bacterial growth. Speak with your doctor if you’re noticing any changes in your body.

How Do I Find Out What Foods I’m Intolerant To?

To check for food intolerances, different tests are available. For lactose intolerance, there's a hydrogen breath test — you drink a hydrogen-containing liquid and breathe into a container at intervals, with elevated hydrogen levels indicating undigested lactose.

Non-coeliac gluten sensitivity lacks a specific test, but for coeliac disease, a blood test can reveal abnormal antibody levels. No current test exists for histamine intolerance, and food allergy tests don't cover intolerances.

As a result, your doctor might suggest keeping a food diary to monitor meals and symptoms. Alternatively, you can eliminate the suspected food for two to six weeks. If symptoms disappear and return upon reintroduction, you may have a food intolerance.

How to Treat a Food Intolerance

Oftentimes, a food intolerance is treated by changing your diet to limit or remove the problem foods. When symptoms do occur, an over-the-counter medicine like antacids or antidiarrheals can help.

There are also foods available without the offending proteins, such as lactose-free milk. You can also take lactase pills before consuming dairy products or add lactase drops to milk to break down the lactose.

Food Intolerances and Anxiety

There is a relationship and influence between our brain and our digestive system, known as the Gut-Brain axis.

In our bodies, food intolerances are mediated by IgG antibodies, a type of immune cell. symptoms related to IgG reactions can often include joint pain, IBS, depression and anxiety, which is not often talked about when discussing food intolerances.

The opposite is also true: our gut bacteria influence our immune system, endocrine system and central nervous system, so anxiety and stress can also affect the types and amounts of gut bacteria we have, increasing one’s susceptibility to food intolerances.

Food intolerances and inflammation go hand in hand, which have been found to have an association with depression. One study found those with depression had higher levels of a marker of inflammatory disease, so managing stress, depression and anxiety can help improve food intolerances.

Can I Take Supplements to Help My Food Intolerances?

Certain intolerances can lead to low levels of essential vitamins and minerals. For instance, lactose intolerance may result in insufficient calcium and vitamin D intake found in dairy. Those avoiding gluten should focus on consuming fresh vegetables, fruits and gluten-free whole grains for adequate fibre and B vitamins. To address potential deficiencies, dietary supplements or multivitamins can be beneficial.

There’s also a link between food intolerance and stress, so incorporating stress-relieving measures may help. Ashwagandha extract has shown positive outcomes in reducing stress, anxiety and depression. Magnesium, such as Xandro Lab’s Magnesium Glycinate, aids in neurotransmitter regulation, reducing stress and improving sleep quality. Curcumin, an anti-inflammatory, can also help by reducing oxidative stress and promoting gut health.

While there may not be direct supplements for food intolerances, these options can indirectly enhance overall health and alleviate symptoms.


Learn more about your body and the vitamins and minerals it needs to stay healthy by reading our blog!