Unit 17 - Food Allergies and Intolerances
What are allergies that infants often outgrow?
- Cow's milk, wheat and eggs
What test is used most often to show if someone is allergic to something?
- Double-blind, placebo-controlled test
Skin prick tests
- For absence of food allergy only - positive results do not prove an allergy exists
Immunoglobin E (IgE) Test
- IgE protein produced in response to an allergen - IgE test does not identify allergen
MSG (monosodium glutamate)
- a flavor enhancer used on meats and in soups, stews, and many Chinese food items - referred to as "Chinese restaurant syndrome" - sensitivity causes dizziness, sweating, flushing, rapid heartbeat, and ringing in the ears
Anaphylactic shock (definition)
- a massive reaction of the immune system that can result in death - people can be saved by an ingestion of epinephrine
Wheat Allergy (Celiac Disease)
- autoimmune disease - characterized by inflammation of the small-intestine lining resulting from a genetic gluten intolerance - causes diarrhea, fatty stools, weight loss, vitamin and mineral deficiencies - treated with a gluten-free diet
True food allergies
- can cause a spectrum of problems from a rash or an upset stomach to death
Unreal food allergies
- can cause people to eliminate nutritious foods from their diet unnecessarily, resulting in inadequate diets and health problems
Histamine (definition)
- caused dilation of blood vessels, itching, hives, and a drop in blood pressure, and stimulates the release of stomach acids and other fluids
Lactose maldigestion
- characterized by reduced digestion of lactose due to low availability of the enzyme lactase
Allergens
- components of food that trigger the immune system - genetically susceptible people experience an allergic reaction by exposure to even trace amounts of an allergen trigger
Double-blind, placebo-controlled test
- determines the presence of a food allergy or other adverse reaction to a food - neither patient nor care provider knows whether the suspected food or a placebo is tested - the test must be administered under medical supervision
Symptoms of Food Intolerances:
- fatigue, joint pain, diarrhea, vomiting, bloating and rashes
Symptoms of lactose intolerance:
- flatulence - bloating - abdominal pain - diarrhea - "rumbling in the bowel"
Sulfite (definition)
- food additive that has been used by food manufactures to keep vegetables and fruits looking fresh and to prevent mold growth - also added to some beers, wines, processed foods, and medications as a preservative
Food Allergen Labeling and Consumer Protection Act of 2004
- helps consumers with food allergies find offending foods and ingredients - food ingredient labels are not required to state clearly whether the food contains one or more of the big eight allergenic foods
Food Intolerances cont...
- people with food intolerance can usually tolerate a small to moderate amount of the specific food, and develop symptoms only when the food is eaten frequently or in large amounts
Food Intolerances
- produce some of the same reactions as food allergies, but the reactions develop by different mechanisms - do not directly involve the immune system - due to a missing or abnormal enzyme or other cause - more common than food allergies, and the onset of symptoms is usually slower
What do most allergic reactions contain?
- rash, diarrhea, congestion, and wheezing
In what foods are histamines found that can cause migraine headaches in sensitive people?
- red wine, beer, sardines, anchovies, hard cured sausages, pickled cabbage, spinach, catsup
Antibodies (definition)
- signal the body to secrete histamine causing the physical signs of allergic reaction
Bogus tests
- some companies offer food allergy tests though the mail, but they tend to be unreliable
What happens in the response to allergens?
- the immune system prompts the formation of antibodies - when the exposure happens again, the antibodies recognize the allergen
Treatment of Food Allergies:
- the only treatment is to eliminate the food from the diet - allergy shots are not yet available - Medical ID bracelets or necklaces are recommended
When can foods be labeled as "gluten-free"?
- when they contain less than 20 parts per million of gluten
What percentage of the population does Celiac Disease effect?
1%
3 Primary reasons people experience adverse reactions to food:
1. Food poisoning 2. Food allergies in which the body's immune system reacts to a substance in food that it identifies as harmful 3. Food intolerances, which are other adverse reactions to normally harmless substances in food - the immune system is not involved
What percentage of the general public believe that they are allergic to one or more foods?
20-30%
What percentage of humans does lactose maldigestion occur in?
65%
What is the incidence in food allergies estimated to be in adults and children?
Adults - 3% Children - 6%
What is the gold standard diagnostic test for celiac disease?
Small bowel biopsy and examination of cells for signs of damage due to the disease.