Introduction to Citizens

1
Introduction to Citizens Jury on GM Food

• Professor Kathy Sykes
• University of Bristol
• 4th April 2003

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Overview

• A) Intro to Nature of Science
• B) Food Safety
• C) Intro to Genetics
• D) Intro to Genetic Modification
• E) Potential Benefits and Risks
• F) Current GM Usage

3
A) Introduction to the Nature of Science

• We all want certainties truth
• Science cant deliver the truth can rarely
  deliver certainties
• Scientists make models that try to approximate
  the truth
• Then try to knock down old models
• Experiments hard to prove things
• just show something is extremely likely... not
  usually 100
• Not usually possible to say no risk

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the Nature of Science

• A big issue we all want certainties
• Scientists often asked to give them
• Its not their job!
• Biological Sciences are v young
• Dont let scientists make it sound like we
  understand it all
• Challenge all your witnesses
• Dont be fobbed off with words you dont
  understand

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Challenging your witnesses...

• Be PROUD to say you dont get it
• Its THEIR job to be clear
• They are here for YOU
• if you dont understand they are failing
• But DONT expect them to say something has no
  risk!
• Lifes risky they cant know all the risks

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Good questions to ask

• I dont understand
• What does xxxxx etc mean?
• How do you know that?
• Whats your evidence?
• What about the risks we havent thought of yet?
• Are we still learning how to do this?
• What are the possible consequences people have
  suggested?
• Is this widely accepted? By whom?

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People youll meet?

• Witnesses - wide range of backgrounds with v
  different views
• Some very supportive of GM others have big
  concerns about it
• Challenge them all!
• Youre free to probe, question
• And you can change your mind
• there are lots of different issues and lots of
  points of view to hear

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B) Food Safety - very controversial!

• Existing risks
• a) Chemicals
• any substance, eg oxygen, plants, foods, us...
  chemicals arent bad
• but most things bad for us in high
  concentrations. Even oxygen!
• many foods (even organic ones) have residues of
  particular chemicals herbicides/pesticides/fungici
  des/ fertilisers (approved fertilisers can be
  used on organic foods)

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Food safety - existing risks

• a) Chemicals - fertilisers etc
• lots of work done on their effects
• EU - safety regs set max limits
• b) Change of DNA in plants by Radiation/Chemicals
  
• since WWII to make useful crops weve zapped
  crops with radiation or chemicals to randomly
  change DNA in the hope of a useful offspring
  plant
• c) Added ingredients
• E nos (colourings, flavourings, preservatives) an
  e-number means its been through safety
  assessment

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How are GMfoods assessed?

• Standard approach called
• Substantial equivalence.
• - compares new food with existing equivalent food
  
• - assesses whether new food has greater risks
  than existing one

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How are GMfoods assessed?

• Substantial equivalence
• takes into account
• characteristics composition of the new food and
  old food
• knowledge of all the parts of the new food, eg
  any genes added, method used to introduce them
  how they are expressed
• processing (including cooking)
• amount of the food consumed and by whom and the
  dietary pattern

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Risks more generally...

• Deaths per year UK 2000
• Accidents 10,000
• Road accident 3,600
• Accidental deaths
• in the home 4,000 (1999)
• Variant CJD 20
• Food borne illness 500
• food-related anaphylactic
• shock mostly peanuts 7
• TB from milk 2-3000 (1930s)
• Cardiovascular disease 73,000
• Cancer 136,000
• GM food related none (yet!)

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C) Intro to Genetics

• What is a gene?
• the thing that carries all the instructions that
  define different characteristics of a plant,
  animal or human being
• Theres a gene that determines
• your hair colour
• your eye colour
• the size of your feet
• a single gene can be key
• usually many genes involved

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When do genes become active?

• - at different times of your life
• They can be switched on or off
• But genes are being switched on or off at all
  stages of your life

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Where are your genes?

• Every single cell in your body has a complete
  copy of all the genes that were needed to create
  you

Credit National Human Genome Research Institute,
United States
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Inside the nucleus

• Inside each human cell is a nucleus
• Which contains 46 chromosomes

Scanning probe microscope image of human
chromosomes T J McMaster, Wellcome Trust Medical
Photographic Library
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Inside the chromosomes
The chromosomes provide the structures that carry
our DNA, which is what carries our genes. DNA has
two strands which twist around each other in the
double helix structure. Genes are made of DNA.
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DNA

• about 6 feet of DNA in a cell
• carries all the genes
• long molecules, scrunched up
• Not just us who have DNA
• Animals, Plants, Bacteria, Fungi
• ANYTHING which is living

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How similar are our genes to others?

• We share about 98 of our genes with chimps
• Surprising!
• Must mean that the way they work together is very
  complex..
• just a few genes can make a huge difference

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Genetic fingerprinting

• Every human cell has the whole info pack needed
  to create a person
• Each info pack is unique
• Just a hair or flake of dandruff
• - left at the scene of a crime
• - can lead to identification of criminal
• get a few cells
• copy them again and again
• see how the persons DNA looks

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D) Introduction to Genetic Modification

• What is Genetic Modification?
• - change the genes in some way
• - alter the DNA
• 1) switch a gene on or off while keeping all the
  DNA the same (eg switch off a gene that makes
  fruit soften, so the fruit keeps for longer)

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What is GM?

• 2) take a bit of DNA from one species, and insert
  it into another
• - from a plant to another plant
• - from an animal to another animal
• - from a human to another human
• AND
• - from a plant to an animal
• - from an animal to a human
• - from a bacteria to a human
• - or anything to anything!

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Step-by-step guide to doing GM

• Taking a gene from one plant and inserting it
  into another
• GETTING THE GENE
• a) find a plant with a characteristic you want eg
  longer lasting fruit
• b) locate the gene that produces this
  characteristic
• c) cut that gene out of plants DNA
• but its fragile - needs packaging...

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Making the Gene Package

• a) attach gene to a carrier
• - bit of DNA from bacteria (plasmid)
• b) add a type of switch to help gene work
  properly (a promoter)
• c) add something which will identify which cells
  in new plant take up the new gene (marker)

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Making the Gene Package
But now we just have one gene package not very
useful alone
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Replicating the gene package

• a) insert gene package into a bacterium
• b) get bacteria to reproduce to create many
  copies
• Now we have enough gene packages
• to make an impact on another plant

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Getting gene package into other plants

• a) usually done in 1 of 2 ways
• fire gene package at high speed into plant tissue
  (on a bit of metal)
• put into a soil bacteria (which invades tissue of
  the new plant)
• b) grow plant tissue into plants
• c) check plants to see that new gene is working
  as it should
• grow
• see
• plant
• repeat

While monitoring that the gene is still there
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Have we done anything like this before?

• Long history of changing genes, for
• tastier foods
• hardier crops
• faster horses
• more interesting pets
• mated different kinds of animal or plant to
  change characteristics
• eg broccoli, maize, roses, poodles

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Our past influence...

• Shire Horses Shetland Ponies
• Twice the height 5x the weight

Credit Shire Horse Society
Credit British Horse Society
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Other waysweve changed DNA

• After WWII zapped plants with radiation or
  powerful chemicals
• to make DNA mutate
• hoping 1 of the mutations will create a useful
  property in next generation
• if useful property is produced
• use plant to produce more plants, and so create
  useful new crops

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Past methods vs Genetic Modification

• Some argue that GM is next step on from selective
  breeding
• Some say GM is more efficient.
• selective breeding quite random
• get characteristics you didn't want
• mixing 1000s of genes
• takes many attempts
• GM can target just a few genes
• Takes fewer attempts

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Past methods vs Genetic Modification

• Changing DNA using
• radiation or powerful chemical
• GM methods are almost certainly more efficient
  than this method, where its just down to chance
  whether a mutation creates a desirable
  characteristic
• More often mutations occur that result in a less
  desirable plant.

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Past methods vs Genetic Modification

• BUT
• with GM changing 1or2 genes may still affect
  other characteristics than just the one you were
  targeting (remember complexity of genes)
• being more efficient means changing a species
  in a shorter timeframe in a more directed way
• Some argue that causing relatively rapid change
  is incredibly powerful, and potentially very
  dangerous

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Past methods vs Genetic Modification

• AND GM offers more possibilities!
• Can put genes from one thing into something
  completely different
• eg put jellyfish genes into plants
• Some believe that crossing barriers like this,
  mixing together say plant human genes, is
  messing with nature and is wrong
• Certainly its a whole new dimension needs
  very careful consideration

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E) Some potential Benefits of GM Crops

• GM foods could help feed the world?
• We can already feed the world!
• a) improved properties for farming
• Crops resistant to particular pests
• so less pesticide can be used
• Crops that are resistant to diseases
• Crops that give bigger yields
• b) crops with new qualities
• higher nutritional value
• better tasting
• need less processing/ fewer additives
• keep better

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Benefits?

• c) plants making completely new crops or valuable
  things
• Medicines
• Plants that act as factories eg rice that
  produces vitamin A
• Edible vaccines a banana that produces a
  hepatitis vaccine
• Useful new activities
• plants with very specific useful properties eg
  growing a biodegradable plastic

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Benefits?

• Useful new activities
• Biosensors to detect when levels of toxins get
  dangerous (yeast modified with jellyfish genes
  detect toxins that damage DNA )
• Terminator crops (cant produce the next
  generation)
• prevents spread of pollen from GM crops to native
  species
• BUT farmers have to keep buying new seed each
  year (especially of concern in developing
  countries)

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E) Some potential Risks of GM Crops

• People have concerns about
• the long term
• Environmental effects
• Health effects

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Risks - Environmental

• a) GM plants becoming weeds
• may be even harder to get rid of than current
  weeds?
• b) transfer GM genes to wild relatives/sim crops
  growing nearby
• could have unforeseen consequences
• wild relatives might develop herbicide resistance
  or pest resistance

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Risks - Environmental

• a) GM plants becoming weeds
• b) transfer GM genes to wild relatives/sim crops
  growing nearby
• c) transfer GM genes to other species of plant or
  bacteria etc
• Horizontal gene transfer
• could have unforeseen consequences
• unexpected properties in plants/ bacteria
• d) pests / insects may became resistant to the
  new GM crops
• - that were designed to resist pests

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Risks - Environmental

• a) GM plants becoming weeds
• b) transfer GM genes to wild relatives/sim crops
  growing nearby
• c) transfer GM genes to other species of plant or
  bacteria etc
• d) pests / insects may became resistant to the
  new GM crops
• e) impact on farmland wildlife
• English Nature, the RSPB and others concerned.
  Being studied in the UK farm scale evaluation
  programme

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Risks - Health

• Some say health risks are small
• we eat DNA all the time
• once broken down in the gut, one bit of DNA looks
  very much like another
• no health effects reported to date
• - though the USA has been eating GM foods for
  almost a decade

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Risks - Health

• Others say we are still not certain
• enough of the possible impact.
• bit of DNA from the GM plant may end up in human
  cells
• from plant to human, most think, chances are
  extremely small
• BUT may be easier for genes to go from plants
  to bacteria
• there are bacteria in the human gut
• some say genetically changed DNA in bacteria
  might make it into humans

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Risks - Health

• current area of concern is about some of the
  marker genes
• (ones added to gene package to show which
  cells have taken up new GM DNA)
• some marker genes can resist particular
  antibiotics
• so some concern that gut bacteria might become
  antibiotic resisting
• then the person wouldnt respond to treatment
  with that particular antibiotic

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F) Current GM Usage

• Where are you likely to see genetically modified
  things?
• Several vaccines medicines made by genetic
  modification
• eg organisms (usually bacteria) modified to
  produce more antibiotics, than they produce
  naturally
• or can produce entirely new medicines by
  insertion of a completely new gene
• Medicines include Hep B vaccine, insulin for
  diabetics.

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F) Current GM Usage

• Relatively few GM foods are currently available
  in the UK
• tomato paste
• GM soya
• GM maize
• BUT soya maize present in many processed
  foods eg soups, sauces, pre-prepared meals
• small amounts (up to 1) present

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Current GM Usage - Worldwide

• In 2002
• soya bean crop - over half was GM
• cotton - 20 was GM
• maize - 9 was GM
• oilseed rape - 11 was GM
• Countries growing GM foods
• Argentina, Australia, Bulgaria, Canada, China,
  Columbia, Germany, Honduras, India, Indonesia,
  Mexico, Romania, South Africa, Uruguay, USA
• live or travel here likely to be eating some GM
  ingredients in processed foods. We import food
  from these countries too.

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4 Different ways GM is used in food production

• a) GM Food
• A crop (eg fruit vegetable) or an animal
• where you eat the GM thing directly
• Whats allowed
• No human, animal or fish genes approved for use
  in GM food anywhere in the world.
• Labelling
• No FRESH GM produce approved for sale or
  consumption in the UK.
• GM tomatoes have been approved, but only sold as
  tomato puree. Have to be labelled as containing
  GM tomatoes

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4 Different ways GM is used in food production

• b) GM ingredients
• Food that comes from a GM crop, like
• GM soya, which has been processed. GM
• DNA is still in the food can be identified
• Whats allowed
• Many processed foods, like biscuits and sauces,
  contain GM ingredients up to 1 may be present
  with no label
• Animals can be fed on GM ingredients without
  their products (eg milk, meat) being labelled.
  Most animals eat some GM
• Rules are being extended so that animal feed is
  labelled when it contains any material that comes
  from GM sources.

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4 Different ways GM is used in food production

• c) GM derived ingredients
• Food that comes from a GM crop, where
• its been processed to such an extent
• that the DNA is broken into fragments.
• Its no longer possible to find out that
• the food has come from a GM source
• Eg soy oil, made from GM soya bean,
• cant be distinguished from soy oil made
• from non GM beans

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4 Different ways GM is used in food production

• c) GM derived ingredients
• Whats allowed
• Currently, this approach is allowed, and the oil
  can be sold without being labelled
• Labelling
• Rules are being extended so that foods must be
  labelled when they contain any material that
  comes from GM sources even if its not possible
  to tell. This will probably happen in a year or
  so
• But how will this labelling be enforced?
• by a paper audit trail so no piece of paper
  means you can assume non-GM

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4 Different ways GM is used in food production

• d) GM used to help processing
• A GM organism can be used to make a
• product, without the GM material being
• present in the final product
• eg you can genetically modify bacteria to make an
  enzyme CHYMOSIN which curdles milk to make
  cheese
• (avoids having to take rennet from calves
  stomachs, the traditional method)
• Then you use the CHYMOSIN, not the GM bacteria,
  to make milk. So no GM product gets into the
  cheese

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4 Different ways GM is used in food production

• d) GM used to help processing
• A GM organism can be used to make a
• product, without the GM material being
• present in the final product
• Most cheese is made like this
• Whats allowed
• Its allowed as long as no GM product ends up in
  the food
• Labelling
• Not required

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Finally

• Enjoy it a rare opportunity!
• Remember to
• challenge
• ask for explanations
• be free to change your mind