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Food Allergy vs Food Intolerance

How to Determine the Difference


Food Allergy and Food Intolerance

and What to do about it.....


Food Allergy and Food Intolerance are commonly confused, as symptoms of food intolerance occasionally resemble those of food allergy. However, food intolerance does not involve the immune system and does not cause severe allergic reactions (known as anaphylaxis). Food intolerance also does not show on allergy testing. 

Food intolerance, also known as Food Sensitivity, can be a difficult concept to understand and is poorly understood by doctors as well. Sometimes, substances within foods can increase the frequency and severity of migraine headaches, rashes (such as hives) or the stomach upset of irritable bowel.

Professional diagnosis and confirmation of allergens is important. Food Allergies and Intolerances are increasing in Infants, Children and Adults.    It is important to identify them and then get to the root of the problem.   The symptoms of Allergies and Intolerances may range from mild and annoying to very severe and life threatening.   Therefore, these reactions should always be taken seriously.


Food Allergy vs Food Intolerance




Food Allergy Prevalence is Increasing

Allergies in general are on the increase worldwide and food allergies have also become more common, particularly peanut allergy in preschool children. About 60 per cent of allergies appear during the first year of life. Cow’s milk allergy is one of the most common in early childhood. Most children grow out of it before they start school.

Food Allergy can be Inherited

Children who have one family member with allergic diseases (including asthma or eczema) have a 20 to 40 per cent higher risk of developing allergy. If there are two or more family members with allergic diseases, the risk increases to 50 to 80 per cent.

Most of the time, children with food allergy do not have parents with food allergy. However, if a family has one child with food allergy, their brothers and sisters are at a slightly higher risk of having food allergy themselves, although that risk is still relatively low.


Allergy is an Immune Response

Allergies are an overreaction of the body’s immune system to a protein. These proteins may be from foods, pollens, house dust, animal hair or molds. They are called allergens. The word allergy means that the immune system has responded to a harmless substance as if it were toxic. 


Foods Intolerance is a Chemical Reaction to Foods

Food intolerance is a chemical reaction that some people have after eating or drinking some foods; it is not an immune response. Food intolerance has been associated with asthma, chronic fatigue syndrome and irritable bowel syndrome (IBS). 



Food Allergies and Intolerances 


It can be difficult to tell the difference between the symptoms of food allergy and food intolerance. Usually, symptoms caused by food allergy develop very soon after consuming the food. While symptoms caused by food intolerance can be immediate, they may also take 12 to 24 hours to develop.

Food intolerance reactions are usually related to the amount of the food consumed. They may not occur until a certain amount (threshold level) of the food is eaten, but this amount varies for each person.

The symptoms of food allergy and intolerance can also be caused by other conditions, so it is important to see your doctor for a medical diagnosis. 


SYMPTOMS of FOOD INTOLERANCE (occur within 20 min to 72 hours after eating)

  • nervousness
  • tremor
  • sweating
  • palpitations
  • rapid breathing
  • headache, migraine
  • diarrhea or constipation
  • burning sensations on the skin
  • tightness across the face and chest
  • breathing problems – asthma-like symptoms 
  • allergy-like reactions.
  • Nausea
  • Gas or bloating
  • Brain Fog
  • Muscle pain
  • Fatigue


SYMPTOMS of FOOD ALLERGY (usually come on immediately after eating):

  • itching, burning, and swelling around the mouth
  • swelling of face or eyes
  • runny nose
  • skin rash (eczema) 
  • hives (urticaria – skin becomes red and raised)
  • diarrhea, abdominal cramps
  • breathing difficulties, including wheezing and asthma 
  • vomiting, nausea. 


  • eyes – itching, watering
  • nose – stuffiness, sneezing, running
  • mouth – itching, swelling
  • throat – swelling
  • digestive system – stomach pains, vomiting, diarrhea
  • skin – rashes, such as hives (urticaria) or atopic dermatitis
  • lungs – wheeze, cough, asthma, more common in children than adults
  • central nervous system – headache, irritability, fatigue, convulsions.



Severe Reactions may occur with Food Allergies and May be Life Threatening!

Anaphylaxis is a severe allergic reaction that needs urgent medical attention. Foods (such as peanuts, tree nuts, seafood, wheat, milk, and eggs), insect bites and stings and some medicines are the most common allergens that cause anaphylaxis.

Within minutes of exposure to the allergen, the person can have potentially life-threatening symptoms, which may include: 

  • difficult or noisy breathing
  • swelling of the tongue
  • swelling or tightness in the throat
  • difficulty talking 
  • hoarse voice
  • wheeze 
  • persistent cough
  • persistent dizziness or collapse
  • becoming pale and floppy (in young children).

Several factors can influence the severity of anaphylaxis, including exercise, heat, alcohol, the amount of food eaten, and how food is prepared and consumed.

To prevent severe injury or death, a person with anaphylaxis requires an injection of adrenaline (epinephrine). 

People who are considered by their doctor to be at risk of anaphylaxis are prescribed an autoinjector (such as an EpiPen®) which contains a single fixed dose of adrenaline. They are designed to be used by non-medical people and should be administered into the outer mid-thigh muscle in the event of a severe allergic reaction.   Adrenaline autoinjectors are also available directly from a pharmacy. 



Peanuts, tree nuts, eggs, milk, wheat, sesame, fish, shellfish, and soy cause about 90 per cent of food allergic reactions. Peanut allergy is one of the most common allergies in older children as only approximately one in four children will outgrow peanut allergy. 

 Food Intolerance Gluten wheat


  • dairy products, including milk, cheese, and yoghurt
  • chocolate
  • eggs, particularly egg white
  • flavor enhancers such as MSG (monosodium glutamate)
  • food additives
  • strawberries, citrus fruits, and tomatoes
  • wine, particularly red wine
  • histamine and other amines in some foods.



When symptoms appear within a few minutes of eating the food, it makes pinpointing the allergen an easy task. However, if the cause is unknown, diagnostic tests may be needed, such as: 

  • keeping a food and symptoms diary to check for patterns
  • removing all suspect foods for two weeks, then reintroducing them one at a time to test for reactions (except in cases of anaphylaxis). This must only be done under medical supervision
  • skin prick tests using food extracts
  • allergy blood tests that look for the IgE antibody to specific foods



Since Food Intolerances may come on between 20 minutes and 72 hours after eating it is very difficult to diagnose them based on the symptoms.    It may be helpful to do an elimination diet with food reintroduction to get a sense of Foods that contribute to the symptoms.   However, this is very difficult and time consuming to do.

  • Food Sensitivity Testing: This finger prick Blood Test is an excellent way to identify food intolerances that may be contributing to poor health and nutrition.    This test is typically done at Home with a finger prick and some blood spots.    The lab runs about 100+ foods and tests them for an antibody IgG.   This antibody shows a delayed reaction in the body when certain foods are introduced.


Leaky Gut and Food Intolerances 



  1. Identify Food Allergies or Intolerance by Testing
  1. REMOVE the OFFENDING FOOD Completely for 3 months
  1. Heal LEAKY GUT with:


Dr. G’s Inflammation Smoothie Bundle:
Gut Revive
Probiotic Plus
Arctic Cod Liver Oil
Rainbow Greens
Find Recipe Here



  1. Treat any Underlying Infections:

          Parasites, Candida, Infections in the Blood, or Gut

  1. Balance the Adrenals
  1. Reduce Inflammation and Histamine
  1. Reintroduce Foods after 3 Months:

         1 food at a time for 3 days before next food.


The easiest way to treat a food allergy or intolerance is to eliminate the offending food/s from the diet. Sometimes, the body can tolerate the food if it is avoided for a time, then reintroduced in small doses, particularly for food intolerances.
Before you eliminate or reintroduce foods, seek advice from an Allergist, Naturopathic Doctor, or Nutritionist. 





Allergy prevention in children is an active area of research. Findings to date indicate that: 

  • prenatal – there is no conclusive evidence that avoiding allergens in pregnancy will help prevent allergies in your child
  • postnatal – exclusive breastfeeding during the first four to six months appears to protect against the development of allergies in early childhood.
  • introducing solid foods (including those considered to be allergenic) around six months (but not before four months) is recommended, preferably while continuing to breastfeed
  • breastfeeding – avoidance of a food (including foods considered to be highly allergenic) by a woman while breastfeeding is not recommended 
  • soymilk formula – studies have shown that using soymilk formula does not prevent the development of allergies in children
  • Avoid Cow’s Milk Formula and Soy Formulas:   Instead use Baby Formula that has Goat or Sheep Milk.   These are more like Breast Milk.



Allergic reactions, including anaphylaxis, are common, although deaths from anaphylaxis are rare. Most schools and childcare services are required to have an anaphylaxis management policy in place.
Banning foods is not recommended as it can create a sense of complacency and is difficult to monitor and enforce. A better approach is to educate staff, students and the community about the risks associated with anaphylaxis and put strategies in place to minimize exposure to known allergens. 



To avoid foods to which you have an allergy, learn the terms used to describe these foods on food labels, for example: 

  • milk protein – milk, non-fat milk solids, cheese, yoghurt, caseinates, whey, lactose
  • lactose – milk, lactose
  • egg – eggs, egg albumen, egg yolk, egg lecithin
  • gluten – wheat, barley, rye, triticale, wheat bran, malt, oats, corn flour, oat bran
  • soy – soybeans, hydrolyzed vegetable protein, soy protein isolate, soy lecithin
  • salicylates– strawberries, tomatoes.



  • cereals that contain gluten and gluten products
  • crustacea and their products
  • eggs and egg products
  • fish and fish products
  • milk and milk products
  • nuts and sesame seeds and their products
  • peanuts and soybeans and their products
  • added sulfites in concentrations of 10 mg/kg or more
  • royal jelly (presented as food or present in food), bee pollen and propolis.



If you are interested in Testing for Food Allergies and/or Food Intolerances, please call the office of Dr. Gabrielle Francis to schedule a screening appointment:


Dr. Gabrielle Francis is a Naturopathic Doctor in New York City.  She is also a Chiropractor and Acupuncturist. 

LEARN MORE:  Dr. Gabrielle Francis @The Herban Alchemist

PHONE:  646-596-8215