Nottingham Evening Post

Food -- It's All In The Genes

Genetic engineering. Is it a science too far? Critics fear irreversible consequences to our health and environment. But scientists in the field argue genetically-modified crops are simply the latest development in the battle to provide food for the world's growing population. Environment Correspondent Helen Ward speaks to Professor Don Grierson, one of the pioneers in the genetics revolution.

Exactly what happens when a tomato ripens?

It seems a simple enough question, but Professor Don Grierson has been working on the answer for 25 years.

Because although we all know the texture, colour and smell of fruit changes as it ripens, few people can explain exactly how these changes occur.

So Prof Grierson, head of the plant science division at the University of Nottingham, began research into the specific genes which control the way tomatoes taste and smell.

His work was to lead to genetically -modified tomato puree.

He said: "We are interested in understanding what a change in texture, for example, actually means. It is a very complicated process.

"We started with a tomato. We spent the first ten years doing biology and genetics in a drive to understand it."

"In 1974 we had no plan to make a product. All we wanted to do was understand."

By 1983 the team had progressed far enough to think about not only identifying the genes involved in ripening - but changing, or modifying, them.

Prof Grierson said: "We had spent a great deal of time identifying new genes, trying to explain what their role was in ripening, and by the mid-1980s the only way to be sure what a gene did was to knock it out and see what the plant can't do then.

"We were one of the first labs to identify ripening genes and one of the first labs to work out methods for knocking out genes - called gene silencing."

The work eventually resulted in genetically-modified (GM) tomato paste - one of the first GM products on supermarket shelves in Britain.

But work on genetically-modified plants has opponents who claim tinkering with genes could have far reaching effects on human health and the environment.

The protests were sparked once genetically -modified soya grown in the USA started being imported to Europe mixed with ordinary soya - making it impossible to know which of the thousands of products which use soya, or soya derivatives, had used gm soya.

Soya, or its derivatives, are used in foods including bread, ice cream and baby food.

Sainsbury's has now introduced a policy of labelling its 30 or so products which contain GM soya, but admits that at one time GM food was sold unlabelled because the two types of soya were mixed together making it impossible to know which products the GM version ended up in.

Prof Grierson thinks it was the initial lack of choice which angered some people.

He said: "No one is protesting about the tomato puree as far as I understand. It came on the market two years ago. It is clearly labelled so people don't need to buy it."

Sainsbury's says it sells as much of the clearly-labelled GM tomato puree as non-GM tomato paste.

Supermarket chain Iceland has decided to exclude GM foods from its own brand products.

Spokeswoman Michele Collier said: "It was customers who first highlighted the issue and we decided to look into it because the technology behind GM ingredients has not proved it is safe.

"We took the decision that it was not something we'd like to supply.

"It was a very time-consuming process. About 60% of processed foods contain GM derivatives, including bread, chocolate and vegetarian meals." The Women's Environment Network wants action on labelling. Notts WEN spokeswoman Margret Vince said: "We can't be sure that it's safe to eat yet and there's an important consumer choice issue here because of the lack of labelling.

"Although there is a European law which applies to labelling food containing GM soya, there is no obligation to label products containing oils produced from GM soya and that is what makes up the bulk of GM contaminants in food.

"I'm in no position to say it is unsafe or not. What I am in a position to say is that we can't be sure, and at the moment people don't have the choice."

Prof Grierson said: "I think what is difficult for scientists to communicate to the general public is the level of risk.

"As far as genetically-modified plants have been examined, the risks so far seem to be very, very small and the benefits quite substantial.

"The bottom line is that you do have to look at each gene and each genetic change on a case by case basis.

"There is no way you can argue that all genetically-modified food is bad or dangerous.

"Similarly, there is no way you could argue that any one of the genetic modifications you could imagine must be good."

Worries Over 'Superweeds'

All genetically-modified food in Britain has been imported.

But last year Monsanto, AgrEvo and other biotechnology companies started testing crops on sites throughout Britain, including six in Notts.

Those tests have raised fears that GM crops modified to be resistant to one type of weedkiller could interbreed with closely related wild plants, giving rise to "superweeds" also resistant to weedkiller.

Friends of the Earth food and biotechnology campaigner Pete Riley said: "The test sites in most cases are not testing for the environmental effects but to see whether that variety of GM crop can perform in UK conditions.

"We want a five-year cessation of commercial testing and growing so scientists can study what effect GM crops would have on the environment. "I am almost certain that cross pollination between test crops and wild varieties has taken place."

Prof Grierson said: "If that weedkiller is used the weeds will be resistant, but there are half-a-dozen others that will kill it.

"As far as I can see, a weedkiller-resistant gene will offer no advantage to a plant in a natural environment." But campaigners say we cannot be sure. Mr Riley said: "The biotech industry claims that this technology will reduce the need for weedkiller.

"But if a farmer sprays weeds and nothing happens then he will have to spray again with another weedkiller, doubling the amount used.

"What we don't know is what weedkiller use will be like after ten years of commercial growing."

Another type of genetic modification makes crops insect-resistant, meaning insecticide use can be reduced.

But wildlife groups point out that knocking out part of the food chain - however it is done - could have far reaching effects.

Alastair Bright, spokesman for the Royal Society for the Protection of Birds, said: "We are not against GM foods or crops, but we feel more research is needed before they can be introduced.

"Together with English Nature, the Government's advisory body on wildlife, we are calling for a three-year moratorium on the commercial growing of GM crops.

"It is felt there are potentially increased risks from GM crops which will increase intensive farming, making farms even more inhospitable places for wildlife.

"With wildlife on its knees this has the potential to be the fatal blow."

In the autumn, the Government announced it would be bringing in a programme of managed development of GM crops, including monitoring for ecological effects.

And it has agreed with the industry that no insect-resistant GM crops will be introduced into the UK for the next three years.

Genetically modifying food is a way to produce more crop for your cash and mankind has always sought to find ways of growing more food.

Prof Grierson said: "If there are significant advantages, such as improved quality, reduced cost, increased safety, kinder to the environment and improved nutritional benefits, then I think we should do it."

Fact File

Within most of the cells of our bodies lie 46 chromosomes which are made up of a molecule called DNA.

DNA is the shape of a ladder, twisted into a spiral.

The length of DNA which forms a chromosome is divided into thousands of sections of code, each responsible for programming a particular job, such as determining eye colour. These sections are called genes.

All features are created by the messages from genes.