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
• Biolistics
• Inserted randomly
• Affect function of plant?
• New substances produced?
• Plants, animals, bacteria, fungi, viruses
• Cauliflower mosaic virus
• Antibiotic resistance
Genetically modified to be:
• Resistant to a herbicide• Make its own pesticide(s)• Both• Multi-stacked
Four main crops
• 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:– Soy
– Canola
– Potato
– Sugarbeet
– Cotton
– Corn
• Present in:– 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
• 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
• Animal testing
• Phase I - toxicity in healthy volunteers
• Phase II - therapeutic effect
• Phase III - randomised controlled trial
• Phase IV - monitor
• Meta-analysis / Cochrane Collaboration
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
• 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
• 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
• 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
CSIRO GM pea
• 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• Long-term feeding studies• Biochemistry• Immunology• Allergies• Neurology• Tissue pathology• Microscopy• Gut Function• Liver function• Kidney function• Full autopsy• Cancer• Reproduction• Teratology
Substantial Equivalence
• 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
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