Hitchhikers guide to Science

Genes make you what you are. All living things have them (humans have about 25,000) and they're like blueprints. Dr Helen Pickersgill looks at the science, use and abuse of...
05 April 2006


Genes make you what you are. All living things have them (humans have about 25,000) and they're like blueprints. So when you're being made, you will get two arms and two legs, rather than wings and a beak. Stuff like that. Genetic modification means changing a gene so the organism does or has something different. It's practically impossible to do in humans and it's only attempted for the treatment of life-threatening diseases. In plants, however, it's much easier and has spawned the current era of genetically modified foods.

I think the reason most people are afraid of GM foods is because they aren't natural like the rest of the things we buy in the supermarket. Like microwave meals, meat and potato pies, and crisps for example. Jesting aside though, even normal fruit and vegetables aren't strictly 'natural'. It's not like the raspberries grew from a stray seed that blew on a gentle breeze into a small crevice and was nurtured by the sun and the rain. What people don't realise is that so-called natural produce has already been forced to change genetically over the years. It's a bit like Hitler's plan to make us all blonde haired and blue eyed, except much less controversial and thankfully far more successful. To do that you only let the blonde and blue eyed people breed. Same with the plants, only choose the ones that look the best and last the longest. These plants have been carefully cultivated for years in artificial environments to make them look as tempting as possible (at the expense of taste unfortunately). These new techniques of genetic engineering just make the process a lot more efficient. If a geneticist (don't be afraid - I know a few and they're charming people) can make my tomato taste like a tomato should, then I applaud them and have no qualms sticking them in my salad (the tomato not the geneticist obviously- scientists thankfully aren't that crazy).

The original GM crops were developed more for the farmers and the retail industries than to make a consumer's life happier and healthier. For instance, maize and rice have had genes added that make them cheaper and easier to grow. This brings me to another common concern over GM crops - the ability of plants to pass on genes to other plants, either directly, or indirectly via a plant pathogen. But this process is inefficient, and we aren't even sure if it's a significant threat and exactly what the outcome would be. It would be like the tomato passing on one of its genes, which makes it look, smell and taste like a tomato, to a potato planted next to it and the potato becoming a bit like a tomato. (Important note: humans cannot pick up genes into their own cells from a plant by eating it or standing next to it). The problems start when a plant is modified, for example, to cope with specific herbicides or insects. If these genes get released into the wild plant populations they will alter this delicate ecosystem, and it may not be able to cope. Worst-case scenario could be that we lose some species altogether and have some plants becoming dominant and growing uncontrollably. The stringent control of GM technologies is paramount to their safety and success, and there are numerous efforts to decrease these potentially devastating effects on the natural plant populations.

The future for GM is more geared towards us, by generating foods that are healthier and have improved quality and flavour. For example, increasing the vitamin content of fruit would massively improve health and the fight against heart disease and cancer. No more need for those vitamin supplements. And you might even find you enjoy eating them rather than considering it a chore to rack up 5 portions of fruit and veg a day, especially when chips don't count. No longer will we finish an orange feeling disappointed and cheated.

As a scientist, sometimes I have to revert to scientific talk, and therefore I cannot state that GM foods are completely risk-free to the consumer. By the same token, nor can I say that eating any food is risk free. Indeed, however harmless the humble apple might appear, it still contains hidden nasties like the cyanide in the pips (in very very low quantities). Genetic modification can pose additional risks to food safety because it's possible that other genes, besides those that you wanted to alter, have been changed too. But importantly, GM foods are tested far more rigorously than any other food you buy at the supermarket, including organic food, because of these potential risks. Health and safety regulations are so extensive that they are preventing many more GM products from making it to market, partly because they are consequently so expensive to produce. However, in reality, GM crops aren't really all that different from the conventionally bred crops. In both cases you are messing around with their genes, but at least with GM you do it in one step by adding a gene which you know the function of, rather than the more hit and miss method of conventional breeding. As long as the genes that have been changed are shown to be non-toxic to humans and not dangerous if released into the wild plant populations, then it's alright by me. Long term effects of eating GM foods awaits the passage of time, but people in the US have been eating GM products since 1993, and there have been no reported cases to date of them being harmful to people.

I think it's essential for everybody to stay open minded and involved in the GM food debate because the potential benefits are extensive. Of utmost importance is the development of this technology for feeding the millions of starving people in the world, which is far more important than putting cheap and tasty food on our plates. Scientists are currently working on developing crops that are less sensitive to extreme weather conditions such as drought or monsoons. But if we can't get past current legislation and address our fears and worries, the third world, who don't have the luxury of choice, are never going to benefit.

Personally I am very excited and positive about this technology. My only request would be to know how a product has been altered and why. Normally I like to know exactly what I'm eating - unless I'm getting a take-away and then I just shut my eyes and enjoy. At the end of the day I have this piece of advice. Whether they're modified or not, always wash your fruit and veggies well before you eat them. I learnt that one from my mum.


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