The lowdown on GM foods

There's probably no topic related to food production that engenders more divergent feelings among consumers than genetically modified (GM) foods.

Some people regard GM foods as toxic and dangerous, while others hail these foods as the solution to mass starvation.

In this article, we consider some of the aspects associated with this hotly debated subject:

GM foods can be defined as foods in which the genetic makeup has been changed so that one or more desirable attribute of the food is enhanced.

Generally speaking, all foods eaten in the 21st century are genetically modified. As soon as man learnt how to cultivate grains, fruits and vegetables and keep domestic animals, genetic manipulation of the characteristics of these food sources began. The human race has, therefore, been involved with genetic modification of foods for thousands of years.

Desirable traits – such as high milk yields in dairy cattle or pest-resistance in crops – have been repeatedly bred into our domestic animals and plant foods.

More recently, selection and breeding of desirable traits in food-producing animals and plants has become more scientific and targeted thanks to the use of genetic modification techniques.

Instead of having to breed plants for many years to obtain the desirable characteristic of drought resistance, scientists are now able to select a gene from another plant that is drought resistant, remove the drought-resistant gene from the parent plant and introduce it into the plant they want to improve.

Similar desirable traits such as resistance to plant pests, increase in nutritive value and the removal of negative components such as those that cause food allergies, can now also be introduced into foods.

So, we need to keep in mind that genetic modification is not new, that it has been going on for centuries and that the modern technique of genetic modification is targeted to improving food supplies and potentially removing harmful food characteristics.

The public reaction
When we speak about GM foods, we immediately enter the realm of conjecture and public hysteria and many readers probably think GM foods are “mutant meals” or "Frankenstein foods".

You may have seen pictures of tomatoes with fish tails, which are used by the media to create public fear and rejection.

Such pictures imply that genes derived from fish are being introduced into tomatoes and that this constitutes a "mutant meal".

Will GM foods affect human health?
Allergic potential
The first question that is always asked when people hear that the genetic makeup of a food has been altered is: “Will this make the food cause allergies?”

While no one disputes the fact that genetic engineering has the potential to transfer an allergenic gene into a previously non-allergenic food, any company that would make themselves party to such an act would be downright stupid.

Put yourself in the position of a company that is trying to improve one of the staple crops of the world, like maize. Would you put the gluten gene from wheat, which causes gluten allergy, into your maize? Or would you stop and think of the consequences and decide that this would be totally self-defeating? No one would want to buy your gluten-enriched maize and you would go bankrupt.

No, if you were trying to enrich maize via genetic engineering you would firstly try and add a beneficial nutrient such as lysine (an amino acid) from a source that is totally free of all allergens.

Secondly, you would test the lysine-enriched maize repeatedly to make quite sure that it does not cause an allergic reaction.

And this is what is being done in genetic engineering. Every step of the way, there are exhaustive tests to ensure that any genetic change in a foodstuff does not increase the allergenicity of the food.

The opposite is actually true. Research is in progress to remove the allergic genetic material from foods such as wheat, soya and peanuts (Madden, 1995).

The Brazil Nut Scandal
Early in the history of GM foods, a Brazil nut protein was cloned to improve the protein content of staple foods and was introduced into soya in the laboratory.

However, before this protein was transferred to staple foods, it was recognised as the major allergen in Brazil nuts and research stopped immediately. No genetically modified, soya-containing Brazil nut protein was ever commercialised and no one has ever died of eating GM soya.

Thanks to this incident, all scientists involved with genetic engineering were given a timely wake-up call. The consumer can now rest assured that no one will ever make this mistake again (FACS, 1999).

It was actually good that the “Brazil Nut Scandal” occurred, because it will prevent future generations of scientists from using any gene that has an allergenic potential in GM foods.

It is probable that GM foods will make positive, instead of negative, contributions to eliminating food allergens.

– (Dr Ingrid van Heerden, registered dietician, for Health24)

(References: (FACS, 1999, Clarifying Common Concerns About GMOs & Biotechnology, Pretoria; Madden, D (1995) Food Biotechnology - An Introduction, ILSI, Brussels)

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