What is a food intolerance?
Additionally, if you regularly eat foods that you are intolerant to, it may be difficult to tie your symptoms to a specific food.
Although symptoms of food intolerance vary, the most common are digestive, skin, and respiratory.
Common symptoms include:
- diarrhea
- abdominal bloating
- rash
- Headache
- nausea
- fatigue
- abdominal pain
- runny nose
- reflow
- flushing of skin
Food intolerances are usually diagnosed through an elimination diet specifically designed to reduce problematic foods or through other testing methods.
An elimination diet removes the foods most commonly associated with intolerances for a period of time until symptoms subside. Then reintroduce foods one at a time while monitoring symptoms.
This diet can help people identify which foods or foods are causing symptoms.
Here are 8 of the most common food intolerances.
dairy
It is broken down in the body by an enzyme called lactase, which is necessary for lactose to be properly digested and absorbed.
Lactose intolerance is caused by a lack of the enzyme lactase, which results in the inability to digest lactose and results in digestive symptoms.
Symptoms of lactose intolerance include:
- abdominal pain
- abdominal bloating
- diarrhea
- gas
- nausea
Lactose intolerance is extremely common.
In fact, it is estimated that 65% of the world's population has difficulty digesting lactose. Intolerance can be diagnosed in a variety of ways, including a lactose tolerance test, a lactose breath test, or a stool pH test. If you think you may be lactose intolerant, avoid dairy products that contain lactose, such as milk and ice cream. For people with lactose intolerance, fermented products like aged cheese and kefir may be easier to tolerate because they contain less lactose than other dairy products.
gluten
Symptoms of non-celiac gluten sensitivity are similar to those of celiac disease and include:
- abdominal bloating
- abdominal pain
- diarrhea or constipation
- Headache
- fatigue
- joint pain
- rash
- depression or anxiety
- anemia
Both celiac disease and non-celiac gluten sensitivity are managed with a gluten-free diet.
It involves adhering to a diet that is free of foods and products containing gluten, including:
- bread
- Spaghetti
- cereals
- beer
- baked goods
- cookie
- Sauces, dressings and gravies, especially soy sauce
caffeine
People who are allergic to caffeine may experience the following symptoms after consuming even small amounts of caffeine:
- rapid heartbeat
- anxiety
- Jitter
- Insomnia
- nervous
- Restless
People who are sensitive to caffeine should try to avoid foods and beverages that contain caffeine, including coffee, soda, energy drinks, tea, and chocolate.
Salicylates
In addition to being a natural ingredient in many foods, salicylates are often used as food preservatives and may be found in medications. Although excessive amounts of salicylates can cause health problems, most people have no problem consuming normal amounts of salicylates found in food. However, some people are extremely sensitive to these compounds and can experience adverse reactions when ingesting even small amounts.
Symptoms of salicylic acid intolerance include:
- nasal congestion
- sinus infection
- Nasal and sinus polyps
- asthma
- diarrhea
- Inflammation of the intestines (colitis)
- measles
While it is not possible to completely eliminate salicylates from the diet, those with salicylate intolerance should avoid foods rich in salicylates, such as spices, coffee, raisins, and oranges, as well as foods containing Salicylates in cosmetics and pharmaceuticals.
Amines
Histamine is a chemical in the body that plays a role in the immune, digestive and nervous systems. It helps protect the body from infection by creating an immediate inflammatory response to allergens. This triggers sneezing, itching, and watery eyes to potentially excrete harmful invaders.
In people without intolerance, histamine is easily metabolized and excreted. However, some people are unable to break down histamine properly, causing it to build up in the body.
The most common cause of histamine intolerance is impaired function of diamine oxidase and N-methyltransferase, the enzymes responsible for breaking down histamine.
Symptoms of histamine intolerance include:
- flushing of skin
- Headache
- measles
- itching
- anxiety
- stomach cramps
- diarrhea
- hypotension
People with histamine intolerance should avoid foods high in this natural chemical, including:
- fermented food
- Cured meat
- dried fruits
- citrus fruits
- Aged avocado
- cheese
- smoked fish
- vinegar
- Sour foods, such as buttermilk
- Fermented alcoholic beverages such as beer and wine
FODMAPs
Bacteria break down or "ferment" FODMAPs, producing gas and causing bloating and discomfort. These carbohydrates also have osmotic properties, which means they draw water into the digestive system, causing diarrhea and discomfort.
Symptoms of FODMAP intolerance include:
- abdominal bloating
- diarrhea
- gas
- abdominal pain
- constipate
FODMAP intolerance is very common in people with irritable bowel syndrome or IBS.
In fact, as many as 86 percent of people diagnosed with IBS experience a reduction in digestive symptoms after following a low-FODMAP diet.
There are many foods that are FODMAPs, including:
- apple
- soft cheese
- Honey
- milk
- artichoke
- bread
- beans
- Lentils
- beer
Sulfite
Common symptoms of sulfite sensitivity include:
- measles
- swelling of the skin
- nasal congestion
- hypotension
- rinse
- diarrhea
- respite
- cough
Sulfites can even cause the airways to constrict in people with sulfite-sensitive asthma, and in severe cases, it can lead to life-threatening reactions.
The U.S. Food and Drug Administration (FDA) requires that the use of sulfites be declared on the label of any food that contains sulfites or that uses sulfites in food processing.
Examples of foods that may contain sulfites include:
- dried fruits
- wine
- Apple juice
- canned vegetables
- pickled food
- condiment
- potato chips
- beer
- Tea
- baked goods
fructose
Consumption of fructose, especially in sugar-sweetened beverages, has risen dramatically over the past four decades and has been linked to increases in obesity, liver disease, and heart disease.
In addition to the rise in fructose-related diseases, there has also been a surge in fructose malabsorption and intolerance. For people who are fructose intolerant, fructose is not absorbed into the bloodstream efficiently. Instead, poorly absorbed fructose passes into the large intestine, where it is fermented by intestinal bacteria, causing indigestion.
Symptoms of fructose malabsorption include:
- reflow
- gas
- diarrhea
- nausea
- abdominal pain
- Vomit
- abdominal bloating
People who are fructose intolerant are often also sensitive to other FODMAPs and may benefit from a low-FODMAP diet.
To control symptoms related to fructose malabsorption, the following high-fructose foods should be avoided:
- soda
- Honey
- Apples, apple juice and cider
- agave nectar
- Foods containing high fructose corn syrup
- Certain fruits, such as watermelon, cherries, and pears
- Certain vegetables, such as sugar snap peas
Other common food intolerances
- Aspartame: Aspartame is an artificial sweetener commonly used as a sugar substitute. Although research is conflicting, some studies have reported side effects in sensitive people, such as depression and irritability.
- Eggs: Some people have difficulty digesting egg whites but are not allergic to eggs. Egg intolerance is associated with symptoms such as diarrhea and abdominal pain.
- MSG: Monosodium glutamate or monosodium glutamate is used as a flavor-enhancing additive in foods. More research is needed, but some studies suggest that large amounts can cause headaches, hives, and chest pain.
- Food colorings: Food colorings such as Red 40 and Yellow 5 have been shown to cause allergic reactions in some people. Symptoms include hives, skin swelling, and nasal congestion.
-
Yeast: People with yeast intolerance usually have milder symptoms than those with yeast allergies.
Symptoms are usually limited to the digestive system. - Sugar alcohols: Sugar alcohols are often used as zero-calorie substitutes for sugar. They can cause serious digestive problems in some people, including bloating and diarrhea.
Food intolerances are different from allergies. Most do not trigger the immune system, and their symptoms are usually less severe. However, they can have a negative impact on your health and should be taken seriously. Many people have intolerances or allergies to foods and additives such as dairy, caffeine, and gluten. If you suspect you may have an intolerance to a certain food or food additive, talk to your doctor or nutritionist about testing and treatment options. Although food intolerances are usually less serious than food allergies, they can have a negative impact on your quality of life. That’s why it’s important to take steps to identify food intolerances to prevent unwanted symptoms and health problems.