Tuesday, May 19, 1998 Published at 16:17 GMT 17:17 UK
Food for the future
Genetically-altered vegetables may soon be available in your local high street
The role of scientists in determining how our food is produced is coming under greater scrutiny than ever before.
The past few years has seen them make significant advances in modifying the genes of animals, vegetables and crops. But the tide is turning against them as concern has grown among the public about the long-term effects of genetically-modified food and animals.
The most well-known development in the area of biotechnology in 1997 was the cloning of Dolly the sheep. She was created for medical purposes rather than for food.
But the year also saw genetically altered crops and chemical residues on fruit and vegetables being blamed for a drop in male fertility.
Despite the criticisms, some scientists have said that more attention should be paid to the benefits food technology can bring.
Eat your greens
Taking up the challenge to create life-enhancing foods by improving on some old favourites is Dr Richard Mithen from the John Innes Centre, a biotechnology research centre in Norfolk.
Dr Mithen is working on modifying the popular vegetable, broccoli.
"It has been known for some years that broccoli contains a chemical that when we eat it, switches on our natural defences against cancer. All the time we are breathing in carcinogens from pollution ... our body excretes these carcinogens, and the chemical in broccoli helps us to do this. Now we have found a wild type of broccoli that grows in the cliff faces in Italy and that wild plant is 100 times more effective at helping us excrete the carcinogens."
The scientists at the John Innes Centre have made a hybrid broccoli plant, incorporating the anti-cancer properties, and Dr Mithen predicts that in three or four years it will be available for public consumption.
Scientists have been injecting foreign genes into animal embryos for more than 10 years, creating new strains that make them more suited to farming or medical research.
Dolly was the largest animal ever to be cloned.
Shortly after her existence was revealed to the world, scientists at the company PPL Therapeutics and the Roslin Institute in Edinburgh made another advance and created Polly the lamb and her four transgenic sisters. Transgenic means the sheep carry a human gene.
By combining two technologies, scientists have made possible the cloning of herds of identical sheep, in order to produce human proteins or blood products for medical use.
The human proteins are found in the sheep's milk, and they can be used to develop drugs for humans that will hopefully have fewer side effects than drugs developed by other methods.
Feed the world
For many people around the world, simply having enough food is their main concern. To combat food shortages science can offer genetically-engineered crops made resistant to insect pests. But it may not be as straightforward as it first appears.
"Genetically-modified maize is being engineered to make it resistant to certain pests - but as a by-product of that process there is also an anti-biotic resistant gene in the genetically modified maize.
"There has been a lot of concern that this will make bacteria increasingly anti-biotic resistant, which would have important implications for human health," she said.
Another concern raised by Dr Bartlett is whether crops that have weedkiller resistance can pass that resistance on to weeds, making them impervious to weedkiller too. Many British crops are not related to European weeds, so it has not been much of a worry, so far.
But Dr Bartlett said that a recent study of oil seed rape, which is weedkiller resistant, has shown that it has passed this property on to the wild radish weed.
Step by step
Concerned about this food revolution, the British Government has delayed licences to allow the new genetically modified crops to be grown in Britain. Wide use of crops resistant to weed killer would clear the way for the mass spraying of herbicides, which could be harmful to the environment.
Some scientists say that this caution is unwarranted and that the spin-offs from plant biotechnological developments will lead to an end to malnutrition, longer lasting food and tastier products.
Unconvinced, the European Commission published plans in November 1997 to require modified products such as corn and soya beans to be constantly monitored, and put on probation for seven years.
Every seven years food manufacturers would have to apply for a new licence and the products would also have to be clearly labelled as "genetically modified".
These moves towards tighter rules are an attempt to dispel public concern at the safety of modern food production. But the European Commissioners are still discussing the policy and a coherent programme has yet to be agreed upon.