Here is a list of the most common food intolerances. You will also learn how a food intolerance is different from a food allergy, how to find out if you have a food intolerance, and what you can do if you are intolerant to a specific food.
Food Intolerances vs. Food Allergy
Food intolerances are not the same as food allergies. While food sensitivity symptoms and food allergy symptoms can overlap, they happen for different reasons.
Here are a few key differences between having a food intolerance and a food allergy.
Definition of Food Allergy
Food Allergies happen because of a reaction by the immune system to foods or certain parts of foods that are allergens.
When the body reacts to an allergen, it releases chemicals called histamines that can cause symptoms. People with food allergies can have digestive, respiratory, and even skin symptoms. People with severe allergies can have a life-threatening reaction called anaphylaxis.
Food allergies are diagnosed with blood tests that measure IgE antibodies, which are produced due to the body’s immune response to certain foods.
Definition of Food Sensitivity
While a food allergy is an immune system response to a food, food intolerance is a problem with digesting foods.
People with food intolerances can have gastrointestinal symptoms like bloating, gas, abdominal pain, and diarrhea after eating certain foods.
Unlike a food allergy, food intolerance does not cause anaphylactic reactions.
Identifying a food intolerance requires careful observation of cause and effect. Some people are intolerant to food additives, like flavorings, dyes, and preservatives.
Elimination Diet’s Role in Diagnosis
One way to try to identify a food intolerance is to use an elimination diet that’s followed by a “challenge” phase in which you re-introduce the food and assess for symptoms.
While the diet can be helpful for figuring out which foods bother you, it doesn’t work for everyone.
Based on your symptoms, you might not be able to tell the difference between food intolerance and a food allergy.
You should work with your healthcare provider to do an elimination diet. Throughout, you will want to keep a food diary, as other factors such as weather, mood, exercise, and menstrual cycles can all affect your gastrointestinal (GI) and other symptoms.
If trying the diet doesn’t help you and your provider figure out what is causing your symptoms, they might want to do other tests. However, food sensitivity tests are not a reliable way to pick up a food intolerances compared to using an elimination diet and food challenge.
Deciding What Foods to Eliminate
If you don’t know which foods you can’t tolerate, it usually it’s helpful to start your elimination diet by avoiding foods that commonly cause the most trouble for people in general. You can choose to eliminate one food at a time, or to eliminate them all at once.
Many people are lactose intolerant. This means that they lack enough lactase, a digestive enzyme necessary to digest the lactose sugar that’s present in dairy products. Dairy products contain a protein called casein. Casein may be hard to digest and can result in inflammation within the digestive system.
Symptoms of Dairy Intolerance
Having a food intolerance to dairy products can cause gastrointestinal and/or respiratory symptoms, as well as skin reactions.
Foods to Eliminate
If you choose to eliminate dairy products to see if you have a food intolerance, you would not eat:
MilkCheeseButterYogurtIce creamAny product derived from the milk of cows, goats, and sheep
Symptoms of Egg Intolerance
If you have a food intolerance to eggs, you may have gastrointestinal symptoms like bloating, nausea, and diarrhea.
Foods to Eliminate
Egg whites have more of the proteins that can cause symptoms, 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 of time, you can challenge the egg yolks and egg whites separately to assess for any reactivity.
If you have a food intolerance to eggs, you can avoid symptoms by following the same dietary recommendations as someone who is allergic to eggs. This can also include avoiding foods like baked goods that are prepared with an egg wash.
Even if you don’t have an allergic reaction when you eat peanuts, you could be intolerant to them.
Symptoms of Peanut Intolerance
Food intolerance to peanuts can include respiratory or digestive symptoms.
Foods to Eliminate
In addition to avoiding peanuts, you’ll want to cut out foods made with them like peanut butter, candies, and baked goods.
Symptoms of Shellfish Intolerance
If you have a food intolerance to shellfish you may have digestive symptoms if you eat it. However, you will not develop a life-threatening reaction that can happen with an allergy to shellfish (anaphylaxis).
Foods to Eliminate
To find out if you are intolerant to shellfish, you’ll want to avoid:
ClamsCrabsLobsterOystersScallopsShrimp
You can have a gluten intolerance instead of a gluten allergy. Some people refer to the digestive symptoms they get from eating gluten as “gluten sensitivity.”
Symptoms of Gluten Intolerance
There is some evidence that gluten sensitivity might be the cause of irritable bowel syndrome (IBS) in some individuals. People with IBS experience a range of digestive symptoms like diarrhea, constipation, and bloating.
Anecdotally, gluten is suspected to be a factor in a wide variety of health and behavioral problems.
Foods to Eliminate
To find out if you have gluten intolerance, you can try following a gluten-free diet where you avoid foods made with certain grains.
Not all grains have gluten. Here are a few examples of grains that have gluten in them:
WheatBarelyRyeSpeltFarinaKamut
You’ll also need to carefully check food labels because gluten can be in bread, pasta, cereals, snack bars, and crackers.
Gluten is also often found in sweets, beverages, condiments, sauces, and processed meats.
Symptoms of Corn Intolerance
In research studies, corn has shown up as one of the top foods to contribute to IBS symptoms, like bowel changes, abdominal pain, and bloating.
Foods to Eliminate
While it can be easy to avoid corn on the cob, canned corn, and popcorn, corn is in a lot of other foods in less obvious ways. You’ll need to read labels carefully and avoid foods that are made with corn products.
For example, many processed foods are made with high fructose corn syrup.
Soy is on the list of top allergens for children, but you can also have a food intolerance to soy.
Symptoms of Soy Intolerance
Anecdotally, many adults attribute their gastrointestinal IBS symptoms to eating soy-based products.
Foods to Avoid
Like corn, soy and its derivatives are now found in many food products. If you’re eliminating soy from your diet to find out if you have a food intolerance, you’ll want to avoid:
TofuEdamameSoy sauceTeriyaki sauceMisoTamariTempehTextured vegetable protein
You must carefully read food labels to see if it contains soy or soy ingredients. Many protein bars, frozen desserts, pasta, cereals, and meat substitutes are made with soy (for example, as soy protein).
Conventionally raised livestock are given corn and soy as primary feed sources, as opposed to grazing on grasses in a pasture. These animals are also given hormones and antibiotics, all of which have the potential to affect the meat that you’re eating.
Symptoms of Meat Intolerance
If you don’t tolerate certain kinds of meat, you might have indigestion, nausea, and bloating when you eat them.
What to Eliminate
If you think that you are intolerant to meat, try looking for pasture-raised animals and do a food challenge with meats, paying attention to the way the animals were raised and fed.
Symptoms of Coffee Intolerance
Many people report that drinking coffee stimulates their bowels. This might be a good thing for some, but for others, certain proteins and chemicals (salicylates) found in coffee may contribute to unwanted digestive symptoms.
Foods to Eliminate
If you’re going to add coffee and coffee beverages like lattes and mochas to the list of foods to avoid on your elimination diet, you will want to wean yourself off slowly to prevent caffeine withdrawal symptoms.
Symptoms of FODMAP Intolerance
High-FODMAP foods can cause digestive symptoms for some people. Research studies have found that following a low-FODMAP diet reduces IBS symptoms in approximately 75% of IBS patients.
Foods to Eliminate
If you think you might be intolerant to high-FODMAP foods, you can try a FODMAPs elimination diet first, then conduct a subsequent food challenge.
A person with a food intolerance gets digestive symptoms like gas and bloating when they eat a particular food. People with an allergy have an immune response to allergens in specific foods, and they can develop serious symptoms like trouble breathing, rashes, and even anaphylaxis.
While food intolerances can be difficult to identify, they are rarely life-threatening. The best way to find out if you are intolerant to a food or an ingredient in a food product is to do an elimination diet under the guidance of your provider.
But the best way to find out if you have a food intolerance is to do an elimination diet.
