Intro to Clinical: Reactions to Food: Allergies and intolerances - Lifecycle test 3

types of food intolerances

carbs lactose fructose

Disruptions in the microbiota and intestinal wall barrier are a result of 6 factors:

cesarean delivery lack of breastfeeding antibiotics chronic stress infections alterations in the microbiota

Eight most common food allergies

milk soy eggs wheat peanuts tree nuts fish shellfish

positive skin-prick test results indicate

only IgE sensitization and the possibility of a food allergy reaction

Food allergy occurs when

oral tolerance fails and the food ingested acts as an allergen causing an immune-mediated reaction

B-cells convert to? ad then what is generated?

plasma cells and the antibodies, or IGE, are generated from the plasma cells

IgE-mediated food allergic reactions are

rapid in onset, occurring within minutes to a few hours of exposure

Food intolerances are

result in clinical symptoms but are not caused by the immune system

anaphylaxis includes

skin-itching, hives, redness, swelling nose-sneezing, stuffy nose, runny nose mouth throat chest heart GI tract Nervous system

Food intolerances are much more common than food allergies and are usually triggered by

small-molecular weight chemical substances and biologically active components of food.

What is essential to the GI tract?

the presence of microbiota which is based on our environment

when the level of tolerated histamine is exceeded in the body what develops?

the symptoms of excessive histamine develop

Dysbiosis exists when...

there is an imbalance in the microbiota in the gut

What nonimmunological mechanisms are food intolerances caused by?

toxins, pharmacological, gastrointestinal, genetic, metabolic, psychogenic, or idiosyncratic (individualistic) reactions

food sensitivity

used when it is unclear whether the reaction is immunologically related or due to a biochemical or physiological defect -not sure if its an allergen, allergic reaction or intolerance

allergen

when the body elicits a hypersensitivity reaction as an allergy

lymphocytes are the

"command and control" cells of the immune system and include B-cells and T-cells

Fructose

-FODMAPs - fructo-, oligo-, di-, and monosaccharides and polyols •Humans lack the enzymes necessary to break down the bonds in fructose polymer chains •Develop symptoms if too much of these CHOs are consumed

2 Assessment tests: 2 Medical Nutrition Therapy:

-Skin prick tests. a Positive skin prick test must correlate with a strong exposure history or be proven to have caused an allergic reactions -Serum antibody tests -Food-elimination diets -Food challenge

Allergen vs intolerance

-allergy: reaction of immune system releases antibodies IgE -intolerance: non immune reaction IgG IgM usuallly takes place in digestive system -The key difference between a food allergy and sensitivity is the body's response. •When you have an allergy, your immune system gets involved. •If you have an intolerance, the reaction is largely triggered in the digestive system.

Atopic individuals are characterized by severe IgE-mediate reactions to? and they present themselves as?

-dander, pollens, food, or other environmental factors -food allergy, atopic dermatitis (eczema), atopic conjunctivitis, atopic rhinitis, asthma, and symptoms in all organ systems and sometimes life-threatening - anaphylaxis

Dysbiosis contributes to

-increased intestinal permeability "leaky gut" which is the increased likelihood that inappropriate molecules will pass through and reach the lymphoid tissue, leading to allergy development

The basic pathophysiology of the allergic response can be described in three phases:

1. The breakdown of oral tolerance 2. Allergen sensitization 3. Reactivity to allergens leading to allergy symptoms

Do children or adults have food allergies more often?

Children

Genetic susceptibility alone doesn't explain the prevalence of food allergies, so what are ways that epigenetic factors may alter gene expression of food allergy and atopy?

Environmental exposures in early childhood such as diet, maternal or family smoking, air pollution, and microbial contact may induce long-lasting susceptibility to influence the development of allergic symptoms

oral tolerance

Exposure to foreign molecules in the digestive tract is followed by immune regulation or suppression, "foreign but safe," which is a precondition for the development of tolerance to a food or food molecule

What is key to maintenance of oral tolerance and avoidance of the allergic response

GI function and the ability to prevent the inappropriate passage of molecules through the intestinal wall

What are the 5 distinct classes of antibodies (immunoglobulin)

IgA, IgD, IgE, IgG, IgM

What also influences whether allergy symptoms develop?

The amount of antigen present to the sensitized immune cell

Carb intolerance

adverse reactions can occur if there is a deficiency of enzymes responsible for carbohydrate digestion•Sugars, starches, and polysaccharides must be broken down by enzymes for optimal digestion and absorption

What is the function of IgEs

allergy antibody that causes an immediate reaction due to the release of chemicals, such as histamine, prostaglandins, leukotrienes, and cytokines from mast cells.

Tyramine is formed from the

amino acid tyrosine and can cause adverse reactions in individuals who are taking monoamine oxidase inhibitors (MAOIs), which interfere with the breakdown of tyramine -MAOI's are depression meds taken to block tyramine -be careful with some foods

Food intolerance

an adverse reaction to a food or food additive that does not involve the immune system and results from the body's inability to digest, absorb, or metabolize a food or component of food

Food allergy

an immune system response that is triggered when a food is eaten by a person who has been sensitized to and causes the release of inflammatory mediators or chemicals that act on body tissues

antigen

any molecule that will elicit an immune response in the body

IgE

are allergic antibodies which cause an immediate reaction due to release of chemicals, such as histamine, from mast cells

Allergen specific IgE antibodies attach to the surface of a mast cell (in the lungs, skin, tongue, and lining of the nose and intestinal tract) by and therefore releasing...

coupling with specific receptors on the cell's surface •Histamine, prostaglandins, leukotrienes, and cytokines

ARF's can affect major organ systems including

dermatological respiratory gastrointestinal neurological systems

ARF

encompasses food allergies and food intolerances, both of which can result in distressing symptoms and adversely affect health

Foods high in histamine content include

fermented foods tomatoes strawberries sauerkraut aged cheeses processed meats and fish alcoholic beverages

Tyramine is found in some

fermented foods (aged cheeses, wines, vinegars) naturally in chicken liver bananas eggplant raspberries plums tomatoes

histamine is released as the

first inflammatory mediator in an allergic reaction or physical defense reaction

Negative skin-prick tests

have good accuracy and suggest the absence of an IgE-mediated reaction

atopy

is a condition of genetic predisposition to produce excessive IgE antibodies in response to an allergen that results in the development of typical symptoms such as asthma, rhinoconjuctivitis or excema

food intolerances do NOT cause

life-threating anaphylactic reactions

etiology to ARF's --what is causing them?

•Genetics and epigenetics •Intestinal barrier integrity •Microbiota •Cesarean delivery and lack of breastfeeding •Stress •Psychological factors •Exercise •Environmental factors •Physiological factors such as changes in hormone levels

Symptoms of Food Intolerances are often similar to food allergy and include GI symptoms, cutaneous, respiratory, and neurological manifestations, specifically:

•Headaches •Nausea/vomiting •Stomach pain •Gas/cramps/bloating •Heartburn •Diarrhea •Irritability/nervousness

symptoms of food allergies

•Itching in your mouth •Swelling of lips and tongue •GI symptoms, such as vomiting, diarrhea, or abdominal cramps and pain •Hives •Worsening of eczema •Tightening of the throat or trouble breathing •Drop in blood pressure •Chest pain •Anaphylaxis