While allergies and intolerances to certain foods can share similar physical symptoms, a true food allergy can be life threatening. It is pretty common to have some reactions to certain foods but in most cases symptoms are caused by an intolerance or sensitivity rather than a true allergy.


Food allergies are an immune system response that is usually characterized by symptoms including rash, hives, nausea, upset stomach, diarrhea, shortness of breath and in some severe cases, anaphylaxis. An IgE-mediated food allergy happens when your immune system detects something in the food as harmful and creates antibodies to attack it. When those antibodies are produced, they attach to pro-inflammatory cells which release histamine and other cell chemicals causing allergic reactions. Allergic reactions can often occur even when a trace amount of the offending food is ingested, so complete exclusion of the food or foods is essential.

Allergies can also be caused by non-IgE-mediated reactions involving different parts of the immune system. Symptoms of this kind of reaction are generally much less severe and the onset of symptoms usually happens many hours after the food is ingested. The Severity of symptoms can depend on the amount of food consumed. A small dose may be well tolerated while a large dose may not. Many non-IgE reactions are believed to be T cell mediated and common reactions include skin problems such as rash, eczema and abdominal upset. While it is much more common to have an IgE-mediated food allergy, people can have a mixture of both IgE and non-IgE mediated responses.


The body’s immune system makes antibodies called immunoglobulin E (IgE). When you ingest a food you are allergic to, the antibodies react with that food and can cause symptoms of allergic reactions. The most common foods associated with true IgE-mediated food allergies include:

Tree Nut

A blood test measuring antibodies can indicate whether a person has an allergy to one of the foods listed above. While these foods are the most common ones involved in allergic reactions, it’s important to know that a person can have an allergy to any type of food.


Not all people who have reactions to certain foods have allergies to them. They may have a more common reaction called food intolerance or sensitivity.  Having an intolerance to a specific food or groups of food is not the same as having a food allergy. A food allergy is when the body’s immune system reacts abnormally to the ingested food. Food intolerance can be caused by various problems but the immune system is not involved. No allergic reaction takes place when someone has food intolerances.

Food intolerance occurs when the ingredients or compounds in a food irritate the digestive system or when a person is unable to properly digest the food. Symptoms of food intolerances are not caused by the immune system.  The onset of symptoms caused by food intolerance is usually slower and can be delayed by many hours or even days.  Intolerance to several foods is not uncommon and that is why it is more difficult to identify which foods or substances may be responsible for chronic symptoms.

Many people suffer from food intolerances or sensitivities, which can be the cause of many symptoms and health issues including:

Digestive disorders
Gas, cramps, or bloating
Irritable bowel syndrome (IBS)
Crohn’s disease
Headaches or migraines
Chronic fatigue
Joint pain
Skin disorders
Behavioral issues

Symptoms caused by intolerances vary by person and the time it takes for the reaction to occur after the food is ingested depends on many things. If the food is only eaten occasionally, then symptom onset ranges from an almost immediate reaction to several hours, up to two days. When the causative food is being consumed on a regular basis each reaction will run into the next, leading to the development of chronic, almost continual symptoms with no clear immediate reaction each time the food is eaten. This is why food intolerances are more difficult to identify than a food allergy.


Food intolerance can cause considerable health problems and significant symptoms when this problem goes undiagnosed for long periods of time.

Some examples of food intolerance are:

Lactose intolerance

happens when the body lacks the enzyme lactase that effectively digests the sugar in milk. A lactase deficiency is something that can be developed or you can be born with either a low level or without any at all. Symptoms of lactose intolerance usually cause abdominal symptoms such as bloating, diarrhea and stomach cramps when milk or any dairy products containing lactose are ingested.

Gluten intolerance

happens when the body can’t digest gluten found in wheat, barley and rye. People sensitive to gluten often have gastrointestinal problems and can suffer from fatigue and headaches. If you suspect you may have a gluten intolerance you should be tested for celiac disease. Celiac disease is an autoimmune disorder where the ingestion of gluten to leads to damage in the small intestine. Symptoms of these two conditions can be closely related and the primary cause should be identified as soon as possible.

Chemical intolerances

can happen from ingesting foods with naturally occurring chemicals such as histamine, tyramine and phenylethylamine. Some examples of food and drink containing these chemicals are wine, beer, coffee, chocolate, cheese, processed meats, tomatoes and strawberries. After consuming food or drink with high quantities of these chemicals, someone intolerant can experience symptoms such as flushing, headaches, stomach upset, itching, runny or blocked nose or irregular heartbeat.

Intolerance to food additives

can be caused by a wide variety of natural and artificial additives used in preserving, processing and coloring foods. Symptoms can be brought on by ingesting additives such as MSG, sulfites and food dyes. Many people share a common sensitivity to MSG which is known to cause headaches and stomach upset.


If you suffer from some of the symptoms or conditions associated with allergy or food intolerance, it is important to get tested to identify your triggers. For someone who has chronic ongoing symptoms, testing is a critical component in addressing poor health and disease prevention. Food intolerances illicit inflammatory responses within the body and are responsible for many health issues you may not realize are connected to the food you eat.

ALCAT offers tests designed for detecting food and chemical intolerances to over 450 substances. They offer many different testing panels depending on how many of those food/substances you want included. K3 NOW uses it to help our patients discover which foods or substances trigger an inflammatory response in the body and may be contributing to a wide range of health issues and or symptoms. We review the results with you to determine the right way to optimize your diet for better health.

If you choose ALCAT testing, you will receive easy to read results and your food and chemical substance test will be broken down into four categories depending on the severity of your intolerance. K3 NOW works with you so that you understand which foods can be eaten without symptoms, which foods can be rotated in and out of your diet to avoid problems and which foods should be avoided altogether.

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