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

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

• 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

RR soy – reproduction study

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

Things that could go wrong

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

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?

www.iher.org.au