Genetically Modified Foods

What is a Genetically Modified (GM) Food? Foods that contain an added gene sequence Foods that contain an added gene sequence Foods that have a deleted gene sequence Foods that have a deleted gene sequence Animal products from animals fed GM feed Animal products from animals fed GM feed Products produced by GM organisms Products produced by GM organisms

Why are foods genetically modified?  Genetic engineering offers a rapid and precise method of altering organisms as compared to traditional methods that are slow and inaccurate.

 Vegetables  Tomatoes  Potatoes  Rice  Cheese  Meat Their genes are usually modified to make the crops pest or herbicide resistant Examples of GM food

5 1994: Flavr Savr © tomato 1994: Flavr Savr © tomato – the first approved GM food product - tomato genes are usually modified to delay ripening and softening

How is genetic modification possible?  The components of DNA are the same in all organisms.  Sequences that code for proteins can be moved from one organism to another.

How can DNA be moved from one organism to another? Its quite simple, REALLY!!!

How can DNA be moved from one organism to another? ► Find an organism with the desired trait ► Isolate the gene sequence that codes for the desired trait ► Insert the gene sequence into the genome of the plant cell

How can DNA be moved from one organism to another? ► Allow the genetically altered cell to grow into a plant ► Allow the plant to propagate

How can DNA be moved from one organism to another?  A vector can carry DNA. The vector can be a pellet from a gene gun. Viruses and bacteria also can be utilized to transfer genes.

Role of GM Foods in EMs Very important for developing countries/EMs – –By 2050  pop. 9b  food strategy for next 20 yrs – –Need more food, as such hunger and starvation – –3m deaths/year in Africa solely relating to hunger – –3 options: aid/food, money/funds, provide GM foods GM foods GM foods: Rapid, accurate, ↑ yield, ↓ labor, ↑ shelf-life

Advantages of GM Foods… Pest resistance – –Crop loss due to insets  financial loss to farmers – –So, farmers use tons of pesticides/fertilizers annually – –GM eliminates pesticides and thus ↓ cost of production Disease resistance – –Viruses, fungi, bacteria  plant diseases – –GM crops resistance to these diseases Cold resistance Frost can destroy sensitive seedlings – –Antifreeze gene from cold fish  tobacco and potatoes

Advantages of GM Foods Drought resistance – –More population  ↑ land for housing, ↓ land for farming – –Land unsuited for plant cultivation  Africa, dessert – –GM crops  grow in draughts or ↑ salt-content soil Nutrition – –Single crop (rice) cannot give all the nutrition needed – –Lack vitamin A  blindness  common in EMs – –GM food: golden rice has Vitamin A (beta-carotene) – –GM food: with enhanced iron is underway, Europe? Pharmaceuticals – –Edible vaccines in tomatoes and potatoes – –Easier to ship, store, administer than traditional injections

Criticism of GM Organism/Foods…

Criticism of GM Foods… Environmental hazards – –Unintended harm to other organism Difficult to design toxin  kills crop-damaging pests, not other insects – –Reduced effectiveness of pesticides Develops resistance  DDT – –Gene transfer to non-target species Cross-breeding Transfer of herbicide resistance from crops to weeds The “superweeds” will then have herbicide tolerance as well Solution – –Create buffer zone

Criticism of GM Foods… Human health risks – –Allergenicity – –We already have allergies to peanuts and other foods… – –Introducing gene may create more allergies – –Unknown effects on human health – –However, proposal to introduce a gene from Brazil nuts into Soyabeans was abandoned On the whole, with the exception of possible allergenicity, scientists believe that GM foods do not present a risk to human health!

Criticism of GM Foods Economic concerns – –Lengthy and costly process – –May be patented Monsanto, Novartis, Dow, DuPont hold patents for GM crops Make substantial profit by exporting it to EMs – –Farmers from developing countries/EM cannot afford – –More gap between rich and poor Other invention  discouraged/stopped – –Suicide gene technology Only one growing per season Next time would produce sterile seeds that do not germinate

Governments and GM Foods… 2009: 25 countries

Governments and GM Foods Europe: Anti-GM protests (Austria, France, Hungary) Europe: Anti-GM protests (Austria, France, Hungary) Japan: Japan: GM testing is mandatory. Customers for organic USA: FDA  GM foods are substantially equivalent to natural food, so not subject to FDA regulations – –GRAS  Generally Recognized As Safe India: No policy yet  for GM  ↓ poverty Brazil: Some states have banned GM crops – – ↑ Smuggle to compete with grain-exporting countries Africa: EU opposes the use of GM in Africa – –S. Africa, Sudan, Zimbabwe have GM laws; Kenya Act  2009 Argentina : Indifferent New Zealand: NO GM Foods grown here!

GM Food Labeling No need to label  same wrt to nutrition No need to label  same wrt to nutrition Europe and Japan  Mandatory Europe and Japan  Mandatory –1% contamination of unmodified products with GM foods –Consumers have the right the know the information –Let consumers decide  but no choice –Reduced sales, so processors do not sell GM foods –EU has disguised policy of protectionism Canada and US  Voluntary Canada and US  Voluntary –Mandatory for Non-GM foods –Let consumers decide  more choices

Homework Assignment  How do you feel about GM foods? Are they beneficial or harmful?  Compare and contrast articles of your choice  Write a short report on your views about GM foods.

Possible Risks of GM Foods  Insects might develop resistance to pesticide- producing GM crops  Herbicide-tolerant crops may cross- pollinate weeds, resulting in "superweeds"

Possible Risks for GM Foods  Certain gene products may be allergens, thus causing harm to human health  There may be unintended harm to wildlife and beneficial insects Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.