Food safety issues, GMOfood, Food allergens, Hazards, risks, tresholds,

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Food safety issues, GMO-food, Food allergens,
Hazards, risks, tresholds,
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Food and Chemical ToxicologyVolume 42, Issue 7,
Pages 1043-1202 (July 2004)

• Safety Assessment, Detection and Traceability,
  and Societal Aspects of Genetically Modified
  Foods
• European Network on Safety Assessment of
  Genetically Modified Food Crops (ENTRANSFOOD)
• Edited by H.A. Kuiper, G.A.Kleter, A. Konig, W.P.
  Hammes, I. Knudsen

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Literature data
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New GM variety An integrated approach to hazard
assessment characterisation of all elements
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Demonstration of unintended effects by phenotype
selection or investigation of defined
constituents
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Assesment by omics- based analyses
Joung J.Nutr 2001, Oliver Nature 2000, Go J.
Nutr 2003
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Plant protein 2-D databases
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Example Automated data-analysis
(metabolite-profiling)
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3H NMR spectra of tomatoes, signals of a
selection of metabolites
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Antibiotic resistance genes as markers
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Other marker genes are also in use
RIKILT Report 2000.004.
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Hazards, risks, tresholds
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Example

• Allergic response as a potential hazard

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Genome Res. Institute
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What is an allergy anyway?

• Hypersensitivity diseases
• Disorders,
• caused by excessive / aberrant immune responses,
• causing tissue inflammation and organ dysfunction
• In some texts Hypersensitivity and sensitivity
  are synonyms for allergy!

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Summary of hypersensitivity reactions
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• Adapted from Saarinen, Lancet 1995

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Allergic urticaria, angioedema
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Basic allergens in foods

• Proteins
• - most important allergens
• Carbonhydrates
• Mostly polysaccharides
• dextran anaphylaxis (cross reactive with some
  Pneumococcus polysaccharides) 
• glycoproteins
• lipopolysaccharides
• Fats, lipids
• Phospholipids (lecithin, cephalin)
• Sterols ( cholesterol, ergosterol, phytosterols
  etc)

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sensitisation via the lungs

• May occur in adults mostly by inhalation, as
  occupational exposure
• Examples
• Bird/egg syndrome
• Plant food proteins
• E.g. 2S albumins and alpha amylase and trypsin
  inhibitors of cereals

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Cross-reactivity
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Cross- allergies examples-I.

• Common allergen Bet v-1allergen family
• First described as birch pollen allergen
• Present in other tree pollens, carrot, cherry,
  and hazelnut
• some other homologues
• apple Mal d1,
• Celery Api g1

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Cross- allergies examples-II.

• Shrimp major allergen
• (Pen a 1) is muscle protein Tropomyosin
• Tropomyosin is important allergen in
• Other crustaceans like lobsters, crab, oyster
• Butvertebrate tropomyosin is not allergenic
  high structural homology with human tropomyosin

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Major allergens of Birch (bet v1) and of apple
(Mal d1) are related Cross-allergies!
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Oral allergy syndrome (Recent name Plant-food
allergy syndrome)

• In hay fever patients (seasonal allergic
  rhinitis)
• Sensitised against
• Pollen allergens, e.g. grass or birch pollen
  allergens
• Oropharyngeal ithcing, sometimes laryngreal
  oedema
• Caused by cross-allergens! (E.g. from apple, mal
  d1!)

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EC-funded project (SAFE)

• Aim to reduce incidence of food allergies by
• Identifying apple allergens as test model
• Mal d1-4 were identifed, cloned and sequenced
• RT-PCR and ELISA tests were developed to detect
  allergen specific m-rna and protein in apple
  cultivars
• Allergen genes were mapped on a molecular linkage
  map of apple

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Hazards, risks, tresholds of allergens

• Hazard
• intrinsic capacity of a food component to induce
  an allergic response
• Primer /secunder risks
• Statistical likelihoods of allergic response to a
  food component at non-sensitise/sensitised people
• Treshold
• The (lowest) estimated eliciting dose (EED)

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Range of estimated eliciting doses

• EED Broad ranges ! Examples
• For peanut
• EED from 100 µg to 1 gram
• For hazelnut
• EED From lt100 µg to 100 mg

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Factors influencing EED

• Patient- related factors
• Age, body weight, asthma status, allergy (pollen)
  season for patients with OAS,
• oral allergy syndrome
• Medication, excercise, alcohol intake
• Product related factors
• ingredient source (cultivar), purity,
  processing (heating etc) fat content, form (e.g.
  milk liquid whole, non fat dry or infant formula
  etc)

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New EU directive on labelling foods

• In principle
• All ingrediens have to be listed with some rare
  exceptions
• only with scientifically established proof for
  not causing adverse reactions)
• BUT major allerginic foods have to be listed

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Major allergenic foods listed in Annex III of the
EU labelling directive

• Cereals containing gluten (wheat, rye, barley,
  oats, spelt or hybridized strains)
• Crustaceans, Eggs, fish,peanuts, soybeans, milk,
  nuts, mustard, sesame seeds and their products
  thereof
• Sulphur dioxide and sulphites at conc. of more
  than 10 mg/kg or 10 mg/liter expressed as SO2

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Allergen databases, internet
BMC Structural Biology2002, 2, 8.
http//www.biomedcentral.com/1472-6807/2/8.