Steve Connor: Purple tomatoes sow seeds of doubt

Few subjects are able to generate as much heated controversy as GM food. Attempts about 10 years ago to get the British public to accept the idea of food that had been genetically modified failed miserably, largely because of the furore over "mad cow" disease and the fact that the GM food on offer seemed to be of no benefit to anyone but the multinational agro-chemical business.

Now up pops another attempt. A team of British scientists announced this week that they had developed a purple tomato with health-promoting properties. They genetically engineered the plant's DNA by inserting a couple of genes from the snapdragon plant. These snapdragon genes boosted the production of pigments called anthocyanins, found in blackberries and blueberries, within the fruit of the tomato plant (yes, tomatoes are a fruit, scientifically, although in the kitchen we think of them as veg, presumably because we add salt to them).

Professor Cathie Martin of the John Innes Centre in Norwich, where the study was carried out, said that an anthocyanin-stuffed tomato could help ward off all sorts of illnesses, from cardiovascular disease to cancer. The GM purple tomato is designed to offer choice to the consumer, she said.

But what do they taste like, I asked her? They taste good, she said somewhat coyly. There is a problem here, as no one is technically allowed to eat a whole GM tomato because of the risk of seeds in the fruit escaping into the outside world through the human digestive system. Such an act would constitute an unlicensed release of a GM organism in to the environment – which would be unlawful.

After some further questioning, Professor Martin explained that the seeds were carefully removed from the purple tomatoes before the fruits were expertly tasted. Phew, what a relief.

Not the retiring types

Two giants of British science are having to step down from their university posts because they have reached the compulsory academic retirement age of 67. Of course, Richard Dawkins and Stephen Hawking are not the sort of people you'd expect to shuffle off sedately. But it does make you wonder why the rest of us in the non-academic world cannot retire at 67 rather than 65 if we choose to, especially given that private sector pensions are now worth even less than the generous schemes of the public sector?

Cool for cats

Scientists from the Zoological Society of London have found that the sabre-tooth tiger was a party animal. A study has concluded that the extinct cats were not solitary but hunted in packs. Much like tabloid hacks.