The impact of an improved diet on offenders' discipline is to be examined in a study with possible implications for the justice system, say scientists.
An improved diet could improve behaviour, study organisers say
A £1.4m study of 1,000 inmates at three young offenders institutions will look at the effect on behaviour of vitamins and other nutritional supplements.
The study involves institutions in Hindley, Greater Manchester, Lancaster Farms, Lancs, and Polmont, Falkirk.
A 1990s pilot project found fewer disciplinary offences were committed.
The young offenders will be monitored to see if a daily regime of vitamins, minerals and fatty acids has any effect on levels of violence, drug-taking and suicidal tendencies.
One of the organisers of the study, Oxford University professor John Stein, said: "We are not saying that nutrition is the only influence on behaviour but we seem to have seriously underestimated its importance."
Inmates, including convicted murderers, will be given more than 30 supplements to their normal prison diet. A control group will be given placebos.
They will keep diaries of what they eat and undergo regular blood tests to make sure they are taking the supplements.
Bernard Gesch, from the charity Natural Justice, said: "It may seem a little strange that what we eat has got anything to do with criminal justice.
"This is potentially something that is very simple, very humane. It is likely to be very cheap and it has been largely overlooked."
Prisons Minister David Hanson said: "I welcome this study... I hope that it will shed further light on the possible links between nutrition and behaviour among young people."
A pilot study at Aylesbury Young Offenders Institution between 1995 and 1997 found that inmates who received vitamins and other supplements committed one quarter fewer disciplinary offences, and 37% fewer violent offences.