Food Intolerance, Food Sensitivities & Food Allergy: The Quick Guide

Food intolerances, sensitivities, and allergies can drastically affect your diet and overall quality of life. Adverse food reactions affect nearly 35% of the population, resulting in gastrointestinal symptoms, such as bloating, cramping, and upset stomach. Like most things, understanding the mechanisms, diagnosis, and treatment can be difficult. We’re going to discuss some of the most common adverse food reactions, involving food intolerances, sensitives, and allergies, what the cause of food sensitivity is, and how you can take preventative action, to put you back in the driver’s seat of your health and wellness.

What Are Food Intolerances, Food Sensitivities, and Food Allergies 

Before we dive in, we first need to define and discuss the three most common types of adverse food reactions: food intolerance, food sensitivities, and food allergies.

What Is Food Intolerance

Food intolerance is a non-immunological reaction to food, when an individual has malabsorption caused from enzyme deficiencies, making it difficult for your digestive system to process those foods. The most common food intolerance, arise from sugar intolerance, such as lactose and fructose.

Lactose, a sugar found in milk contains an enzyme called lactase, which is responsible for breaking down lactose. Those with dairy sensitivities or intolerances may have lactase deficiencies, resulting in bloat, gas, and upset stomach. Undigested lactose, finds its way to your colon and your gut bacteria ends up breaking it down, resulting in gastrointestinal symptoms, such as gas, bloat, and diarrhea.

What Are Food Allergies

Food allergies affect the immune system and occur when the immune system misidentifies a protein as a threat. Your immune system releases antibodies called immunoglobulin E (IgE) to neutralize these threats. Moderate to severe food allergies can result in swelling, hives and can result in a life-threatening reaction called anaphylaxis.

Any food can cause an allergy but overall, only a few foods account for the vast majority of allergies. This includes milk, eggs, peanuts, shellfish, wheat, and nuts [R]. 

What Is Food Sensitivity

Natural and non-natural food chemicals can also trigger another type of adverse food reaction, food sensitivity. Food sensitivities are similar to allergies, as they are immunologically mediated, meaning the immune system is involved. However, unlike food allergies which trigger an immunoglobulin E (IgE) mediated reaction, a sensitivity is triggered by other antibodies in the immune system known as Immunoglobulin G (IgG) and Immunoglobulin A (IgA). 

Food sensitivities, like allergies activate the immune system causing inflammation, bloating, headaches, and skin irritation such as rashes. Food sensitivities can be delayed causing reactions hours or even days later. One of the most common food sensitivities, is gluten sensitivity. However, gluten sensitivity is different than celiac disease, which is an autoimmune disease, mediated by gluten consumption.

What Causes Food Intolerance, Food Sensitivities, and Food Allergies

Histamine, a chemical messenger of the immune system sends and receives signals, causing allergic reactions. Food allergies are your body’s way of reacting to a foreign protein. Usually, allergens are harmless or benign in nature. Sometimes your immune system, can overreact, leading to a cascade of reactions and histamine release, resulting in an allergic reaction. Thus food allergies are caused by an abnormal immune response to a food protein mediated by immunoglobulin E (IgE), non-IgE or mixed IgE/non-IgE immunological mechanisms.

Food intolerance, is caused by an inability to break down compounds, mediated from enzyme deficiency, pharmacological reasons, or non-specific gastrointestinal (GI) functioning [R].

Food sensitivities like allergies, can be immunologically mediated, occurring from the presence of certain chemical compounds in foods.

Common Food Sensitivities


Naturally occurring fermentable carbohydrates termed ‘FODMAPs’ can cause a majority of food sensitivities. This group of oligo, di, mono, and polysaccharides have been shown to trigger symptoms in patients with functional GI symptoms such as in irritable bowel syndrome (IBS)

FODMAPS can be found in foods such as apples, honey and mangos; lactose found in dairy, polysaccharides (largely comprised of sorbitol and mannitol) present in avocado and pears, fructans present in wheat, onion and garlic, and, galacto-oligosaccharides present in legumes and nuts [R].

Wheat sensitivities

Wheat has two parts that contribute to its common food sensitive characterization -  the protein and the carbohydrate fractions. Gluten is the main storage protein found in wheat grain and is a complex mixture of hundreds of related but distinct proteins, mainly gliadin and glutenin. Gluten also exists in rye, barley and oats. The main carbohydrate component, called fructan of the wheat is a FODMAP.

Food Additives And Bioactive Food Chemicals

Thousands of food additives are used in the food industry for various functions, to preserve food, taste, and appearance. These are generally synthetic and cannot be consumed as food themselves.

Eating raw, natural foods can help eliminate processed foods, that may have these additives. Preliminary animal studies, have shown that common additives, such as emulsifiers, stabilizers, and preservatives, can induce low grade inflammation and obesity/metabolic syndrome in wild-type hosts and may impair the epithelial barrier [R].

How To Treat Food Intolerance, Food Sensitivities, and Food Allergies

If you find that you have food sensitivities, a first step and general approach is food elimination. Eliminating the food or foods, that may be causing the symptoms will help establish a baseline. Start with some very basic foods then slowly, over time add foods back one at a time, to identify what foods are causing your symptoms, without to many confounding variables.

The next steps would be to build a strong intestinal lining, a healthy gut microbiome, and digestive enzymes for sufficiently break macronutrients, such as proteins, fats, and carbohydrates.

L-Glutamine, a conditionally essential amino acid, has been shown to build and repair your gut lining.  Glutamine is a vital nutrient for aiding in the process of rapidly dividing cells from the immune system and gut to rebuild and repair [R] L-Glutamine is also proven to help fight intestinal inflammation and help those with food sensitivities. 

Among the various tissues using glutamine at high rates, the intestine utilizes about 30% of total glutamine indicating that it is a key nutrient for the intestine [R]

So how does L-Glutamine help improve digestive health? The specific mechanism of action and role of L-Glutamine is in utilizing nitrogen atoms. Glutamine helps direct the body where and when to place nitrogen atoms in order to rebuild and repair the gut lining. This can be extremely beneficial to improve digestive health and for those that have gastrointestinal issues characterized by gut hyperpermeability such as leaky gut, and inflammatory bowel diseases like Chron’s, IBS, and Ulcerative Colitis.

RELATED ARTICLE What 14 Studies Say About L-Glutamine As A Treatment For Gastrointestinal Health and IBD

RECOMMENDED PRODUCT L-Glutamine (60 Servings)

When you identify those sensitivities, think about adding digestive enzymes.

Digestive enzymes are naturally occurring proteins produced by your body, to help absorb and digest food. Several types of digestive enzymes are released and secreted, starting with the saliva in your mouth to your small intestine and pancreas. The pancreas is considered the epicenter where most of your digestive enzymes are produced. The primary purpose of digestive enzymes is to aid and support digestion. 

There are several different types of digestive enzymes produced by the pancreas. A variety of health conditions, that affect the pancreas can lead to deficiencies in digestive enzymes, which can create malabsorption, nutrient deficiency, and food sensitivites.

  • Amylase– an enzyme secreted in the mouth and pancreas which breaks down carbohydrates.
  • Maltase– created by the small intestine to break down maltose or malt sugar into glucose for energy.
  • Lactase – An enzyme that breaks down lactose and is a sugar found in dairy products. It converts lactose into glucose and galactose. Lactose that is not absorbed is fermented by the gut which can cause bloating and gas.
  • Lipase – Lipase breaks down fat into fatty acids and glycerol.
  • Proteases these are digestive enzymes that break down protein into amino acids. Swolverine’s Whey Protein Isolate adds protease as well as papain from papaya to better digest protein.
  • Sucrase – secreted by the small intestine, sucrase breaks down sugar or sucrose (table sugar) into fructose and glucose.

Adding digestive enzymes to your diet, when your food sensitivities are identified, is also good practice, to help with absorption and to decrease sensitivity symptoms.

Food Intolerance, Food Sensitivities, and Food Allergy: Takeaway

Having adverse food reactions, can be a difficult and complex thing to diagnose. Trying to get control of your gut health can be one of the most frustrating things in the world, and I know from first hand experience. Constantly being bloated, having irregularity, and not being able to identify what is causing your digestive issues, and why, is discouraging to say the least. Taking some of the aforementioned actions, will help, however, it's not that simple. If you're experiencing digestive issues, and can quite figure it out, the best plan of action, is to work with a qualified professional, such as a human nutrition and functional medicine expert. You'll have a direct course of action, to find what the underlying mechanisms are, to help you feel better, look better, and improve your quality of life. 

Need Help With Optimizing Your Diet And Nutrition Plan To Finally Get The Results You've Been Waiting For?

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We believe that everyone can optimize not only their athletic performance but their human potential. The way we believe we can optimize performance is through transparency, clinically effective doses, and clinically proven ingredients with evidence-based outcomes. We provide the nutrients you need to power your active lifestyle.


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