Food Allergies: Nothing to be Nuts Over By :

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Food Allergies Nothing to be Nuts OverBy
The Tree NutsBrielle, Jennifer, and June
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Which Foods Cause Allergies?

• Tree Nuts
• Legumes (such as peanuts and soy)
• Seafood
• Seeds (that can include mustard!)
• Dairy (including whey)
• Eggs
• Commonly outgrown by adulthood
• Other proteins commonly implicated in food
  allergy include chocolate (cocoa), yeast, and
  fruits from the rose (strawberries and other
  berries),, citrus, and plum families, as well as
  food dyes and sulphites. http//www.naspghan.org/s
  ub/Food_Allergy.htm

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Predictors of Food Allergies

• Family history
• -Infants with one allergic parents have about
  twice the risk of developing food allergy than
  infants whose parents do not have allergies.
• -If both are allergic, the risk increases 4-6
  times.
• Breast feeding reduces risk of developing food
  allergy.

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What is the prevalence of a food allergy?

• Estimates for the prevalence of food allergy are
  much lower than are perceived by the public.
• About 1-2 of the adult population have a food
  allergy.
• Higher among young children, with 3-7 affected.

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Helps to Know Botanical Relationships

• For example, if youre allergic to cashews, you
  may also be allergic to mangos.
• But if youre allergic to nuts, youre not
  necessarily allergic to peanuts.
• Cherries and plums are in the same fruit family.

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Mechanisms of the Allergic Response

• Predisposed person first exposed to specific
  food
• IgE is formed after first exposure
• (Tiny protein fragments produce IgE against
  that food.)
• IgE then attaches to surface of mast cells
• Next time protein is eaten, it interacts with
  specific IgE on the mast cells and triggers
  release of chemicals such as histamines
• So the body remembers what it ate previously!
• An individual who has asthma or eczema, or has
  a family history of food allergies or asthma or
  eczema.

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Allergies are not the same as Intoleranceshttp
//www.eufic.org/en/quickfacts/food_allergy.htm
Allergic responses involve the immune
system. Intolerances are metabolic, e.g.
sensitivity to gluten (a protein found in wheat,
rye, barley and oats) or to lactose
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Mechanisms of the Allergic Response

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So Its All in the Proteins

• Specific proteins or portions of the proteins
  found in the offending foods cause reaction
• Epitopes parts of proteins that the body reads
  as foreign
• Each allergy-causing food may contain several
  potential reaction-causing proteins

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Symptoms of Allergic Reactions

• Respiratory
• Gastrointestinal
• Skin
• Systemic (Anaphylaxis)

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Food Allergy Frequencies in General

• Anybody here have food allergies or know someone
  who does?
• 1.5 percent of adults and up to 6 percent of
  children younger than three years old
• Many allergies lifelong (especially nuts)
• Some can develop later in life (such as seafood)
• Roughly 150 Americans die per year from
  anaphylaxis

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The Action of Epinephrine to Counteract
Anaphylaxis
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How Do We Test for Allergies?

• Observation!
• Skin testing (not very accurate)
• Blood serum
• Food challenge

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Allergy Treatment Methods
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Focus on Three Tree Nuts

• Walnuts - particularly strong reaction by some
  individuals to tiny amount of walnut proteins
• Cashews - proteins very stable whether nut is
  roasted, toasted or blanched
• Almonds one of the most common nuts

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Our Local Expert Dr. Shridhar
Sathehttp//www.chs.fsu.edu/nfes/bios/shridhar_sa
the.php

• Has worked for decades to identify the amino
  acid sequences in various foods that cause
  reaction (specialty is nut proteins)
• We now have an assay that can detect as little as
  20 ng of specific protein
• Effects of food processing on allergenicity

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Main Avenues of Research

• Food processing, e.g. various cooking methods, or
  exposure to enzymes to denature proteins
• Immunotherapy (NOT the same as allergy shots,
  since sensitivities increase with each exposure)
• Prevention of degranulation of mast cells

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Mast Cell Degranulationhttp//www.b-p-s-a.org.uk/
mast_cells_and_ic.htm
When mast cells are activated or degranulated
they release irritating substances such as
histamine and leukotrienes. The question is
whether it is possible to prevent their
degranulation, and therefore allergic symptoms.
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Changing the Protein Structure to Prevent
Allergic Responses
Heat doesnt sufficiently denature most nut
proteins. Neither does gamma radiation. But one
piece of good news Since these protein elements
of various nuts are so stable, they are useful in
detecting trace amounts of almonds, cashews and
walnuts in food products.
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Some Thorny Issues

• Cross contamination
• Allergens where you dont necessarily expect
  them, e.g. sesame flour in MOST bread crumbs
• Genetically Manipulated Organisms (GMO)
• International protocols necessary
• Labeling

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References References McMurry,
James and Richard Castellion. Fundamentals of
General, Organic and Biological Chemistry. New
Jersey Saddle River, 2003.Mengna, Su.
Impact of Gamma Irradiation and Thermal
Processing on the Antigenicity of Almond, Cashew
Nut and Walnut Protein. Journal of the Science
of Food and Agriculture, 841119-1125 (online
2004) Sathe, Shridhar K. Personal Interview.
8 October 2004.Websites www.fda.gov/fcac/fea
tures/2001/401_food.html (FDA)http//www.eufic.o
rg/en/quickfacts/food_allergy.htm (European Union
Food Information Center)http//www.foodallergy.o
rg/ (Food Allergy Network).