Transcript Is GM Food Safe to Eat?

Is GM Food Safe to Eat?
Dr Judy Carman BSc (Hons) PhD MPH MPHAA
Director
Institute of Health and Environmental
Research
How GM Food is Made
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Biolistics
Inserted randomly
Affect function of plant?
New substances produced?
Plants, animals, bacteria, fungi, viruses
Cauliflower mosaic virus
Antibiotic resistance
Genetically modified to be:
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Resistant to a herbicide
Make its own pesticide(s)
Both
Multi-stacked
Four main crops
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Corn – tacos, corn chips, cornflour, oil
Soy – bread, baked products, soy milk, oil
Cotton - oil
Canola – oil (margarine)
GM Food in Australia
• Approved as safe:
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Soy
Canola
Potato
Sugarbeet
Cotton
Corn
• Present in:
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Bread
Pastries
Snack foods
Baked products
Oil
Fried foods
Confectionary
Soft drinks
Sausage skins
FSANZ assesses human food safety
• Main role is public health and safety
• Other roles:
– Promote fair trade
– Promote trade and commerce
– Promote consistency between domestic and
international concerns
• None of its own safety testing
• Safe until proven harmful
Unlabelled
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From animals fed GM (meat, milk, eggs, honey)
Highly refined (oils, sugars, starches)
Bakeries, restaurants, takeaways
“Unintentionally contaminated” up to 1% per
ingredient
• Processing aids, food additives using GM
microbes
• GM flavours at less than 0.1%
Clinical Trials
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Animal testing
Phase I - toxicity in healthy volunteers
Phase II - therapeutic effect
Phase III - randomised controlled trial
Phase IV - monitor
Meta-analysis / Cochrane Collaboration
FSANZ policy
• No animal feeding studies needed
• No review of GM company raw data
Information from:
• FSANZ documents
– From GM company applications
– Rarely published data
• Almost nil from independent scientists
FSANZ documents – testing done
• 12 reports for 28 GM plants
• Compositional analyses
• Animal studies
Compositional Studies
• Usually only amino acids
• Usually not fatty acids
• Sometimes anti-nutrients
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Sample size
Mean
Standard deviation
95% confidence interval of mean
Nature of statistical test
P-value
Substantial Equivalence
• Corn MON 810 had 8/18 (44%) amino
acids different
• “Substantially equivalent”
• Royal Society of Canada: “Scientifically
unjustifiable and inconsistent with
precautionary regulation of the technology”
Human and Animal Testing
• No human testing
• Animal testing (of 28 foods)
– No testing (1 corn)
– Acute toxicology of protein
– Whole food
Acute Toxicology
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Of protein expect to find
Only animal testing done for 61%
Oral gavage, observe 7-14 days
Assumes:
– Only new substance is GM’d one
– Plant-produced acts same as bacterially-produced
– Creates disease within 14 days
Animal Testing
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Unusual human health models
Fed 4 weeks
Small sample sizes
Death
Body weights
Sometimes organ weights
“Gross pathology”
Often no data given
Adverse or unexpected effects
• Been found
• Canola GT73
– Increased liver weights 12-16%
– Increased glucosinolates (1/3)
– Meal not fed to humans, so OK
– Oil not fed to animals
• MON863 corn
– 90 day feeding study
– Monsanto – no problems
– Seralini – pattern of toxicity - liver and kidneys
– FSANZ returned study in 10 days
RR soy – reproduction study
CSIRO GM pea
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DNA from bean into pea
Allergy study not needed
Protein the same – glycosylation
Pigs, chickens, rats – poorly digestible
5 measures of allergy abnormal
Cross-priming
Feeding Studies Needed
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Long-term feeding studies
Biochemistry
Immunology
Allergies
Neurology
Tissue pathology
Microscopy
Gut Function
Liver function
Kidney function
Full autopsy
Cancer
Reproduction
Teratology
Things that could go wrong
Substantial Equivalence
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No definition
Showa Denko KK
GM bacteria produced tryptophan
37 died, 1500 permanently disabled
Eosinophilia-myalgia syndrome
• GM organism produced 1 or more dangerous substances
• Highly substantially equivalent (99.6% pure)
• Highly purified
Novel DNA
• DNA for antibiotic resistance
• 7 people with colostomy bags
• Single meal: GM soy burger, GM soy milkshake
• “A relatively large proportion of GM DNA survived
passage through small bowel”
• Evidence of genes from GM soy into intestinal microbes
• GM DNA in cow's milk
• Food-ingested foreign DNA can cross gut wall into blood
leucocytes and into several organs and immune cells.
Novel Protein
• Food allergies (eg peanuts)
• Mad cow disease (new variant Creutzfeld
Jacob disease)
Where are all the sick people?
• Assume that GM food is making people ill.
• How easy would it be to find the proof that
GM food is causing the illness?
Identify the problem
• What do you look for?
• Surveillance systems only for few, existing
diseases.
• HIV/AIDS took decades to find
Investigate the problem
• Surveillance does not give cause – need
investigation
• Competitive research grant system
• Causes suggested – usually known ones
• Food histories problematic
• Hard to find food-related cause
Public Health Action
• Public would want food removed from food
supply
• Hard to find very strong evidence
• Tobacco industry
• Can’t recall it from fields
Scientists Measure Risk
• Probability of something happening
• Consequences if it does
Community measures risk
• Sandman’s model:
Risk = hazard + outrage
Who takes the risk?
Who gets the benefit?
Why take the risk?
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