Allergy Free Info helps people with allergies and food sensitivities navigate a path to healthy living.
Navigating Allergies and Food Sensitivities

Allergies and Sensitivities

Allergy Free Information helps people with allergies and food sensitivities navigate a path to healthy living.

Food Allergies

A food allergy is an abnormal response to a food triggered by your body’s immune system

Food Allergy Symptoms

Symptoms of a food allergy can range from mild to severe, and the amount of food necessary to trigger a reaction varies from person to person. Symptoms of a food allergy may include1:

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  • Rash or hives
  • Nausea
  • Stomach pain
  • Diarrhea
  • Itchy skin
  • Shortness of breath
  • Chest pain
  • Swelling of the airways to the lungs
  • Anaphylaxis (a life-threatening, rapid, onset, whole-body, allergic reaction that includes many of the above symptoms)

Food Allergy Cause

The body’s immune system normally reacts to the presence of toxins, bacteria or viruses by producing a chemical reaction to fight these invaders. However, sometimes the immune system reacts to ordinarily benign substances such as food, chemicals or pollen, to which it has become sensitive. This overreaction can cause symptoms from the mild (hives) to the severe (anaphylactic shock) upon subsequent exposure to the substance.2

An actual food allergy, as opposed to simple intolerance due to the lack of digesting enzymes, is indicated by the production of antibodies to the food allergen, and by the release of histamines and other chemicals into the blood.2

Food Allergy Prevalence (or Frequency) 

In the United States, it is estimated that up to twelve million people have food allergies,3 and the prevalence is rising;4 6 to 8% of children under the age of three have food allergies and nearly 4% of adults have them.5

Food allergies cause roughly 30,000 emergency room visits and 100 to 200 deaths per year in the United States.6

The most common food allergies are allergies to milkeggs, peanutstree nuts, seafoodshellfish, soy and wheat, which are often referred to as “the big eight.”7 They account for over 90% of the food allergies in the United States.8 Allergies to seeds – especially sesame – seem to be increasing in many countries.9

The most common food allergies in adults are2:

And the most common food allergies in children2 are:

Food Intolerance or Food Sensitivity

Food intolerance, or Food Sensitivity, occurs when something in a food irritates or damages a person’s digestive
or nervous system, or when a person is unable to properly digest or breakdown the food.10

Food Intolerance Symptoms

Though food intolerance is a digestive system response, rather than an immune system, some of the symptoms may look and feel like those of a food allergy: 5, 10, 11

  • Nausea
  • Stomach pain
  • Gas, cramps, or bloating (irritable bowel syndrome)
  • Vomiting
  • Heartburn
  • Diarrhea
  • Headaches
  • Irritability or nervousness
  • Skin problems like rashes, hives, psoriasis and eczema
  • Candida and other yeast infections
  • Weight gain
  • Rheumatoid arthritis

Food Intolerance Cause

There are many factors that may contribute to food intolerance. In some cases, as with lactose intolerance, the person lacks the chemicals, called enzymes, necessary to properly digest certain proteins found in food. Also common are intolerances to some chemical ingredients added to food to provide color, enhance taste, and protect against the growth of bacteria. These ingredients include various dyes
and monosodium glutamate (MSG), a flavor enhancer.

Substances called sulfites are also a source of intolerance for some people. They may occur naturally, as in red wines or may be added to prevent the growth of mold.

Salicylates are a group of plant chemicals found naturally in many fruits, vegetables, nuts, coffee, juices, beer, and wine. Aspirin also is a compound of the salicylate family. Foods containing salicylates may trigger allergy symptoms in people who are sensitive to aspirin.12

Food Intolerance Prevalence (or Frequency)

Food intolerances are much more common than food allergies, 8
(see Food Allergy Prevalence above). Intolerance to lactose, which is found in milk and other dairy products, is the most common food intolerance.The symptoms can look and feel like those of a food allergy.10

The five most common types of food intolerance (also known as food sensitivity) are11:

There are also less common sensitivities such as11:

  • Corn (maize) and other grains like millet
  • Soy and soy bean products
  • Sorbitol, polyols and alternative sweeteners such as aspartame, saccharin
  • Nightshade vegetables (potatoes, tomatoes, eggplant, capsicum, peppers, chili)
  • Food additives (artificial preservatives such as MSG, flavor enhancers, colors, etc.)
  • Banana, Avocado, Chestnut, Apple, Carrot, Celery, Papaya, Kiwi, Potato, Tomato and Melons. These fruits and vegetables are often referred to as “Latex foods” since many people with these food sensitivities are also allergic or sensitive to latex.
  • Chia and other seeds

How Can You Tell the Difference Between a Food Allergy and Intolerance

Food allergies can be triggered by even a small amount of the food and occur every time the food is consumed. People with food allergies are generally advised to avoid the offending foods completely. On the other hand, food intolerances often are dose related.

An actual food allergy, as opposed to simple intolerance due to the lack of digesting enzymes, is indicated by the production of antibodies to the food allergen, and by the release of histamines and other chemicals into the blood.2

People with food intolerance may not have symptoms unless they eat a large portion of the food or eat the food frequently. For example, a person with lactose intolerance may be able to drink milk in coffee or a single glass of milk, but becomes sick if he or she drinks several glasses of milk.12

Food intolerance, or Food Sensitivity, occurs when something in a food irritates or damages a person’s digestive or nervous system, or when a person is unable to properly digest or breakdown the food.10

Allergy Cross Reactivity

Cross-reactivity refers to a person having allergies to similar foods within a food group. Cross-reactivity occurs when the body’s antibodies, (or immune response), originally created against a given allergen respond to a different allergen. Most of the time, this phenomenon occurs among allergens that are structurally similar or biologically related.13

For example, all shellfish are closely related; if a person is allergic to one shellfish, there is a strong chance that person is allergic to other shellfish.
The same holds true for tree-nuts, such as almonds, cashews and walnuts.14

When a patient has a confirmed allergy to one food, evaluation of related foods may be indicated to determine if these foods are also problematic.15

Tree nuts, fish, legumes and shellfish are more commonly clinically cross-reactive.14,15

Approximate rates of clinical cross-reactivity are summarized in Table 1.

 

Table 1: Approx. rate of clinical reactivity to at least 1 other related food
If Allergic to: Risk of Reaction to at least one: Risk:
A legume Other legumes 5%
e.g., peanuts, soy carob, peas beans, lentils
A tree nut Other tree nuts 37%
e.g., almonds, brazil nuts, cashews, chestnuts, filberts, hazelnuts,macadamia nuts, pecans, pine nuts, pistachios, walnuts
A fish Other fish 50%
A shellfish Other shellfish 75%
A grain Other grains 20%
Cow’s milk Beef 10%
Cow’s milk Goat’s milk 92%
Cow’s milk Mare’s milk 4%
Pollen Fruits/Vegetables 55%
Peach Other Rosaceae
e.g., plum, pear apple, almond,
strawberry, blackberry, raspberry
55%
Melon Other fruits 92%
Latex Fruit
e.g., bananas, chestnuts, kiwi fruit,
avocado and tomato
35%
Fruits Latex 11%

 

Citations

1

NIH: National Institute of Allergy and Infectious Diseases

http://www.niaid.nih.gov/topics/foodallergy

2

National Institute of Allergy and Infectious Diseases (July 2004).

“Food Allergy: An Overview”

3

Food Allergy & Anaphylaxis Network

“Food Allergy Q & A for Reporters”

4

Kagan RS (February 2003). .. Environ Health Perspect 111 (2): 223–5.

“Food allergy: an overview”.

doi:10.1289/ehp.5702.

PMID:12573910.

PMC:1241355.

5

The Food Allergy & Anaphylaxis Network

www.foodallergy.org

6

The Food Allergy & Anaphylaxis Network

Food Allergy Facts and Statistics” (PDF).

7

Food Additives and Ingredients Association.

“Food allergy and intolerance”. Retrieved 2010-06-08.

8

Asthma and Allergy Foundation of America.

“Common Food Allergies”. March 28, 2007.

9

Food Allergy Initiative

“About Food Allergies”. Retrieved 2008-12-08.

10

MedicineNet.com

Food Allergy.

15

Sicherer, SH. C J Allergy Clin Immunol 2001; 108:881.

linical implications of cross-reactive food allergens.

16

Auckland Allergy Clinic.

Food Cross-Reactions.