Food Safety Assessment Kevin Greenlees, PhD, DABT Kathleen Jones, PhD.
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Transcript of Food Safety Assessment Kevin Greenlees, PhD, DABT Kathleen Jones, PhD.
Food Safety Assessment
Kevin Greenlees, PhD, DABT
Kathleen Jones, PhD
Describes the animal, construct, and proposed claim
Are there sequences that are likely to contain potential hazards to the animal, humans, or animals consuming food from that animal, or the environment? e.g., does the construct contain mobilizable sequences from viruses that may be endemic in that species?
Does the insertion of the rDNA construct pose a hazard to the animal, humans, other animals by feed, or the environment?
Are the genotype or phenotype changing over the product lifespan in a way that would affect the risks associated with the product? Is there a plan in place to monitor those changes?
What are the direct and indirect risks posed to the GE animal? (e.g., can surveying the health and other phenotypic characteristics of the animal inform us with respect to risk to the animal and potential human food safety concerns?)
What are the risks of direct or indirect adverse outcomes associated with the consumption of the GE animal as food or feed?
Food/Feed Safety
What hazards/risks have been identified in the hierarchical review?
If GE Animal Not for Food
Established Food Safety Standard
The food safety standard is reasonable certainty of no harm
– NOT absolute safety
Whole Foods
Toxicological testing of whole foods in animal models is challenging
Complex mixtures Wide variation in composition Impact on dietary balance High dose testing not possible
Outcome Characterization
Approach
Identify and characterize hazards Direct effects Indirect effects
Analytical methods
Direct v IndirectIntended v Unintended
Direct Adverse Effect (Food Safety) adverse outcome resulting from human consumption of edible products from the rDNA animal coming into contact with the construct or its gene product(s)
Indirect Adverse Effect (Food Safety) adverse outcome resulting from human consumption of edible products from the rDNA animal that contain hazards due to the construct or gene product perturbing the food animal’s physiology
Intended effects changes in the rDNA animal brought about deliberately by introduction of the rDNA construct and its predicted gene product(s). These may or may not pose direct or indirect effects on food safety.
Unintended effects changes in the rDNA animal resulting from the interaction of the rDNA construct or its gene product(s) with the physiology of the animal such that its metabolism is altered. These may or may not pose direct or indirect effects on food safety.
Direct Effects
Result from the expression product(s) of the inserted construct directly producing harm
Toxicological testing on case-by-case basisAllergic assessment of proteins new to food
Indirect Effects
Effects other than direct impact of the expression product in food.Nutritional deficiency identified in
compositional analysis
Conceptual Overview of Food Safety Evaluation
Construct Gene Product
Direct Effects
Indirect Effects
Indirect Effects
Direct Effects
None (DNA is GRAS)
Insertional Mutagenesis in structural or regulatory region
Consumption of edible product containing GP causes toxicity
(allergenicity, GI disturbance, other tox)
Metabolic Δ such that consumption of edible tissue may pose risk
(altered levels of expected nutrients, inherent metabolites or sequestered xenobiotics)
Conceptual Overview of Food Safety Evaluation
The previous slide is a graphical summary of how one may approach the evaluation of food safety of edible products from GE animals. It indicates a GE animal, the construct that goes into it, and the resulting gene expression products. It subsequently indicates direct and indirect effects that may occur as the result of the construct or the expression products. The construct is not expected to cause direct effects as the agency has previously determined that DNA is generally recognized as safe (GRAS). Indirect effects caused by the construct could result from insertional mutagenesis in either structural or regulatory regions of the genome.
The gene product can cause direct effects via the consumption of edible products, products containing gene products that cause toxicity (allergenicity, gastrointestinal disturbance, or other toxicity). Indirect toxicity can result from metabolic changes such that consumption of edible tissue that may pose risk, for example, altered levels of expected nutrients, inherent metabolites or sequestered xenobiotics).
For a tolerance For identity
Analytical Methods for GE Animal
Only in food producing animals Only if a tolerance is needed Demonstrates marker analyte present at or
below tolerance in target tissue
Analytical Method for a Tolerance
o Identifies approved GE animal in mixed populationo Determines edible tissue is from approved GE
animalo Discriminates approved product from “knock-off”o Practical in a regulatory laboratoryo May provide useful information if durability failure
Analytical Method for Identity: Characteristics
Food/Feed Safety of
Information Reviewed Sponsor affirmation Animal identification; facilities; containment procedures Animal and product disposition methods and records “Regulatory Method” procedures for transgene identification
for animals and edible tissues
Conclusions Plan likely to ensure that GE animals will not enter the food or
feed supply Regulatory method adequate to identify animals/meat
No food/feed from this lineage of GE animals will enter food/feed supply