These seven common food intolerances can cause a host of digestive symptoms such as diarrhea, bloating, gas, stomach pains, and IBS. Below is a list of the most common food intolerances.
Common food intolerances include:
- high histamine foods
- sulfites and food preservatives
- fat intolerance.
Every individual is unique and may have several food intolerances or one.
Symptoms of food intolerance vary, making it challenging to know what food is causing what digestive symptom. But identifying your food intolerances can make massive improvements in your gut health.
So, what is food intolerance?
By definition, food intolerance is a non-immune-mediated adverse reaction to food caused by any non-protein food component. Any food can cause food intolerances.
Food intolerances are usually caused by a functional digestive weakness or enzyme deficiency. It is estimated that food intolerances affect 20-25 % of the world’s population!
Food allergies involve the immune system. And are often much more severe, sometimes causing life-threatening health conditions. Food allergies affect 1-2 % of the adult population.
Food allergy vs food intolerance
A food allergy causes activation of IgE antibodies to a protein found in food following ingestion. It is the protein component found in food that the immune system creates antibodies.
A functional defect or enzymatic deficiency primarily causes food intolerances. Lactose intolerance or histamine intolerance is often due to an enzyme deficiency.
For example, histamine intolerance can be due to a decreased function in the DAO enzyme in the gut which metabolizes histamine.
Lactose intolerance is a common food intolerance caused by a lactase enzyme deficiency. Lactase is the enzyme responsible for breaking down the milk sugar lactose. If the body cannot break down lactose, the sugar is fermented by gut bacteria leading to excess bloating and gas.
Other people may react to the fat component of milk due to poor bile flow or a lipase deficiency. Another person may be allergic to the cow milk protein casein and will have an immune reaction.
The primary difference between a food allergy vs a food intolerance is that common food intolerances involve the digestive system while food allergies involve the immune system.
Food intolerances can cause a wide variety of digestive symptoms that occur after eating specific foods. The wide range of gut symptoms associated with food intolerances can make it challenging to identify specific food intolerances.
The most common symptoms of food intolerance include:
- Abdominal pain
- Runny nose
People with a food allergy may experience more immediate reactions such as itching, hives, or asthma.
The most common foods that cause food allergies are:
- Peanuts/tree nuts
These seven common allergenic foods account for 90% of all IgE-mediated food allergies.
Common food Intolerances List
1. Lactose Intolerance
Lactose intolerance is a common food intolerance that genetic mutations can cause in the lactase enzyme (LPH). The Lactase enzyme is responsible for breaking down the sugar lactose.
Genetic mutations result in people not being able to digest lactose. It is best to avoid all forms of milk sugar lactose or use a lactase enzyme with milk in this situation.
Lactose digestion and absorption depend upon the intestinal brush border enzyme called lactase phlorizin hydrolase (LPH). This enzyme breaks lactose down into glucose and galactose. These sugars can then be absorbed across the intestinal lining.
2/3 to 3/4 of the human population lose the ability to digest lactose as adults. Only ¼ to 1/3 of adults retain the ability to digest lactose into adulthood. These numbers explain why lactose intolerance is so common among the population.
Lactose intolerance can also be a result of damage to the intestinal lining in the small intestine. When the intestinal villi are damaged, there is a reduction in the intestinal lactase enzyme. Lactase deficiency leads to increased lactose intolerance, one of the most common food intolerances that cause diarrhea.
Undigested lactose will cause excess fermentation of lactose in the colon. If bacteria have overgrown in the small intestine, bacteria will ferment the milk sugar in the small intestine causing digestive symptoms. The excess fermentation of lactose worsens IBS symptoms.
Symptoms of lactose intolerance include:
- Abdominal cramps
- Vomiting/nausea on occasion
It is the rapid fermentation of lactose by gut bacteria into gases that cause symptoms of lactose intolerance. Avoiding lactose is essential for individuals with SIBO as the mild sugar will be fermented upon in the small intestine if not broken down and absorbed.
People with lactose intolerance will often not tolerate milk yet are OK with yogurt or cheese. Specific bacteria added to the fermentation process of these foods result in decreased amounts of lactose.
Most people can tolerate up to 12-15 grams of lactose per day. Strict avoidance of lactose is not always necessary to reduce symptoms of lactose intolerance.
An excellent way to identify if lactose may be problematic for you is to drink a glass of milk. Pay attention to any increased digestive symptoms such as bloating, gas, and abdominal cramps.
Taking a lactase enzyme with milk can be helpful for individuals who have lactose intolerance yes still consume milk and dairy products.
High fodmap foods are another common food intolerance that triggers digestive symptoms in people with irritable bowel syndrome (IBS).
Fodmaps is a term used to describe a variety of fermentable carbohydrates such as:
• Excess fructose in honey, apples, and mangoes
• Lactose present in milk
• Polyols largely compromised of sorbitol and mannitol found in avocado and pears
• Fructans found in wheat, onion, and garlic
• Galacto-oligosaccharides found in legumes and beans
Fodmap related food intolerance symptoms include:
• Abdominal pain
• Bloating flatulence
• Diarhhea/altered bowel movements
Individuals using a low fodmap diet have shown improvements in overall abdominal symptoms, pain, bloating, and bowel habits.
Identifying high fodmap foods that trigger digestive symptoms is often better than strictly adhering to a complete low fodmap diet. Such a restrictive low fodmap diet can result in the loss of bacterial diversity in the colon.
For example, one person may note that fructans in wheat, garlic, and onion are problematic. Yet that same individual is fine with other fodmap foods such as fructose in fruit and polyols.
High fodmap foods are also excellent sources of prebiotics. A diverse variety of prebiotics is needed to provide fuel for probiotic bacteria that produce the gut-healing molecule butyrate.
With SIBO, high fodmap foods are problematic as bacteria in the small intestine rapidly ferment upon fodmaps. This rapid fermentation of fodmaps in the small intestine leads to upper abdominal bloating and gas.
The poorly absorbed short-chain carbohydrates found in fodmaps have an osmotic effect, increasing water delivery into the small and large intestine. The combination of increased water delivery and gas production can lead to pain in people with visceral hypersensitivity.
Working with a qualified practitioner to identify which high fodmap foods are triggers is beneficial for anyone experiencing symptoms of IBS.
Symptoms associated with a wheat food intolerance are:
• Abdominal pain
• Altered bowel habits
• Brain fog
• Musculoskeletal symptoms such as arm numbness
Gluten which is the protein component found in wheat can activate the immune system. When the immune system is activated it releases pro-inflammatory cytokines.
In other words, gluten can cause inflammation by activation of the immune system.
Gluten can increase intestinal permeability, known as leaky gut. The combination of increased inflammation and leaky gut is a disaster for gut health.
The wheat lection agglutinin can also damage the lining of the small intestine leading to increased intestinal permeability.
The high fodmap fructans in wheat can also be the cause of a wheat food intolerance.
Wheat is a common food intolerance due to the gluten, fructans, and lectins that can all cause adverse reactions.
4. Histamine Intolerance
Common symptoms of histamine intolerance include:
• Stomach ache
• Congestion of the nose
• Flushing of the skin, hives, or urticaria
Histamine intolerance occurs when there are elevated levels of histamine that surpasses the capacity of the body to metabolize histamine.
Elevated histamine levels with decreased DAO activity have been associated with various inflammatory diseases such as Crohn’s disease and ulcerative colitis.
Histamine is a biogenic amine found in many foods in varying degrees. The level of histamine amines increases during the fermentation and maturation of food. Foods such as sauerkraut, wine, aged cheese, smoked meats, processed meats, or foods that have spoiled are high in histamine.
High histamine foods include:
- Cheese such as gouda, camembert, swiss, parmesan and cheddar
- Fermented sausage, salami, ham
- Red wine and alcohol
Foods with histamine-releasing capacities include:
- Citrus fruit
- Egg white
If high histamine foods trigger histamine symptoms, it is best to reduce the amount of histamine-containing foods eaten.
Taking a diamine oxidase enzyme supplement with histamine-containing foods will help to metabolize the histamine in food.
5. Food additives and chemicals
Some food additives that can cause adverse reactions are:
- Tartrazine which is a food dye
- Sulfites found in dried fruits and wines
- Benzoic acid
- Monosodium Glutamate
Food intolerance symptoms associated with food additives and chemicals include:
- Gi symptoms similar to IBS
- Nasal congestion
So many food additives allowed in the food industry can cause adverse reactions in the body. To avoid the unnecessary burden of food additives and chemicals try to eliminate highly processed and packed foods.
Instead, eat a whole food diet that is as close to nature as possible. Read the food labels and watch out for the long list of food additives. If you can’t pronounce the name or find the ingredient in nature, it is likely to be a food additive or chemical.
I know shopping is no longer easy with a laundry list of over 1000 food additives and chemicals to watch out for. If possible, it is best to support the local whole food markets. Nothing beats unprocessed whole food!
6. Sucrose and starch
Absence or reduction in sucrase and isomaltase results in undigested sugars in the GI tract. These undigested sugars can then act as fermentable fodmaps.
Symptoms of sucrase and isomaltase deficiency include:
- Abdominal pain
It is the fermentation of undigested sugars due to a sucrase and isomaltase deficiency that can cause these digestive symptoms.
Additional food intolerances to carbohydrates can be due to a deficiency in the enzyme amylase secreted by the pancreas. The amylase enzyme is also found in saliva which is why it is so important to chew your food for optimal digestion.
An inability to digest fats results in symptoms such as:
- Oily stool
- Floating stools
- Deficiency in the fat-soluble nutrients A, D, E, and K
Bile is produced in the liver and stored in the gallbladder. When dietary fats are consumed bile is released. The purpose of bile is to emulsify fats to provide more surface area for the fat-digesting enzyme lipase to act upon. These fats are then broken down into fatty acids that can be absorbed.
Intolerance to fatty foods is often due to poor gallbladder function, thick sludgy bile, or lipase deficiency.
Supporting the gallbladder with gallbladder nutrients to make bile and promote bile flow is crucial for optimal fat digestion.
Gallbladder nutrients can be taken 1o minutes before a meal to help stimulate fat digestion.
A lipase enzyme can be taken with meals containing fat to help with the digestion of dietary fat.
These most common food intolerances cause a wide variety of digestive symptoms and similar adverse reactions. Keeping a food diary with symptoms noted alongside the foods can help you to identify which foods you may be intolerant to.