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Are these claimsclaims supported by evidenceevidence?

Let’s take a look into Let’s take a look into some examples of GM some examples of GM food!food!

Examples of GM Food

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Example 1: GM maizeAbout 7% of the world’s maize (sweet corn) production is lost to a pest called the European corn borer.

The larvae live inside the maize stalk.

Pest control is not efficient. Large amounts of pesticides are used.

The cost of growing maize increases.

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farmers the environment the economy

causes losses to

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A gene extracted from a soil bacterium is inserted into maize

Bt protein

The GM maize can produce a protein called Bt protein.

When the corn borer larvae eat this protein, their intestinal walls are damaged, causing them to die of starvation.

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GM

benefitsbenefits

The cost is lowered, the crop yield

increases.

Less pesticide is used.

Less maize is lost.

Consumers get better quality and Consumers get better quality and more maizemore maize

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Example 2: GM rice GM rice has a higher crop yield (greater

weight of rice per plant).

Who benefits?

Farmers, consumers, economy

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Rice is the main carbohydrate source in many countries.

GM rice increases food supply thus may reduce food shortage.

Who benefits?

People suffering from hunger or in poverty

(rice may be cheaper)

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A new GM rice – golden rice,– rich in pro-vitamin A (a precursor of vitamin A)

People in developing countries suffer from vitamin A deficiency leading to blindness

Golden rice may solve the problem of vitamin A deficiency in developing countries.

Golden riceGolden rice

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A protein in a new variety of GM rice (Bt rice) may cause allergy in humans (NB: this is NOT “golden rice”)

Bad news!Bad news!

Are GM foods safe enough?

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GM foods are supposed to be assessed by each different country before it is allowed onto the market there

GM foods are usually tested for their toxicity and whether or not they cause allergy

Approved GM foods are therefore not likely to cause risks to human health

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But….. The first GM food was marketed only in 1994.

– Long term effects on human health cannot yet be assessed.

Laboratory animals don’t live as long as humans do

Animal tests can’t pick up small effects on intelligence or personality (brain functions)

Trials for food safety of GM crops are often carried out by the companies that have developed them, not by independent researchers.

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Moreover….Some GM food have antibiotic-resistant marker genes

Why?Why?

The desirable gene may be transferred WITH an antibiotic-resistance gene.

By testing the modified organisms with antibiotics, scientists can tell whether the desired gene has been successfully inserted into the “new” organism.

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What is the risk?What is the risk?

The marker genes may be transferred to other pathogens which become resistant, antibiotics will no longer be effective in treating diseases.

This may lead to development of “super pests”

Some GM food have antibiotic-resistant marker genes…

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Does GM food really benefit farmers and consumers?

GM crops are mainly developed by a few large biotechnology companies

The companies have patents on the GM crops genome

Do the farmers need to pay extra to buy GM Do the farmers need to pay extra to buy GM seeds?seeds?

The cost may be higher because the seeds arThe cost may be higher because the seeds are more expensivee more expensive

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Potential risks to the environment?Genes from GM crops might escape, through pollen, to weeds which are relatives of the crops.

i.e. the genes may escape into the wild.

GM crops may be toxic to some insects that eat them.

Dead or dying insects may be eaten by birds.

The birds may die because of the toxic effect.

This may lead to extinction of some species of insects This may lead to extinction of some species of insects or birds.or birds.

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All organisms are interrelated. Changes in one species may have unpredictable consequences in other parts of an ecosystem.

GM crops may grow and reproduce faster. They may out-compete other plants in an ecosystem.

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Ethical problems?

Do we have a right to alter ANY genetic material?

Is genetic engineering unnatural?

Is genetic engineering ‘playing God’?