DVD: Food Inc. (E)

Yes, it's another worrying documentary on how American food is grown, processed and messed with by nasty corporations.

The early sections re-tread well-worn territory (chicken farms; mass production of corn etc). But there is some scary stuff here – the aggressive patenting of genetically modified seeds by biotech giant Monsanto, for example, is sinister.

One early-adopter of organics turned Wal-Mart supplier says of his idealistic Seventies endeavours that he was "preaching to the convinced". This film's importance may be lost on all but farmers' market regulars.