Food allergens

Food allergens

 

Food allergies

Food allergies occur when the body's immune system reacts to certain proteins in food. Food allergies currently cannot be cured.

Symptoms of an Allergic Reaction

Symptoms of food allergies typically appear from within a few minutes to a few hours after a person has eaten the food to which he or she is allergic. A severe, life-threatening allergic reaction is called anaphylaxis.

Symptoms of allergic reactions can include:

• Hives
• Flushed skin or rash
• Tingling or itchy sensation in the mouth
• Face, tongue, or lip swelling
• Vomiting and/or diarrhea
• Abdominal cramps
• Coughing or wheezing
• Dizziness and/or lightheadedness
• Swelling of the throat and vocal cords
• Difficulty breathing
• Loss of consciousness

 

Major Food Allergens

• Milk
• Eggs
• Fish
• Shellfish
• Tree nuts
• Peanuts
• Wheat
• Soybeans

 

Gluten, certain additives (e.g., yellow 5, carmine, sulfites), and emerging food allergens, such as sesame, are examples of other substances.

Gluten

 Gluten describes a group of proteins found in certain grains (e.g., wheat, barley, and rye, oats, spelt or their hybridized strains). In people with celiac disease, foods that contain gluten trigger an immune response that attacks and damages the lining of the small intestine. Such damage may not only limit the ability of celiac disease patients to absorb nutrients, leading to problems such as iron deficiency anemia, osteoporosis, and malnutrition, but it puts them at increased risk for potentially serious health problems, including intestinal cancers and autoimmune diseases such as diabetes.

Colour additive

Colour additives made from cochineal extract and carmine, which are derived from insects.

For example, FD&C Yellow No. 5, widely found in beverages, desserts, processed vegetables, drugs, makeup, and other products, may cause symptoms such as itching and hives in some people. Some individuals may have hypersensitivity reactions to a colour additive.

 Immune Mechanism

        Food allergy refers to the immediate-type IgE-mediated adverse reaction towards food allergens. The immune response is skewed towards a T helper 2 responses, associated with the cytokines IL-4, IL-5 and IL-13. This T cell response leads to the induction of IgE production towards allergens by B cells. IgE in turn binds to the IgE receptor on mast cells. When the allergen is re-encountered, IgE can be cross-linked, leading to degranulation of mast cells. The mediators released by the mast cells lead to the typical allergic symptoms, such as itching or sneezing.