Western countries are seeing a consistent increase in violent crime.

The best efforts by police, zero tolerance campaigns and neighbourhood watch schemes still don't make us feel much safer.

Our prisons are the fullest in Europe but it only makes sense to be "tough on crime, tough on the causes of crime" if we know what the causes actually are.

The criminal justice system seeks to address known risk factors such as social and economic deprivation or substance abuse, yet we ignore one of the most important factors which may have a causal influence - our diet.

In one of the first studies of its kind, researchers at Oxford University found by simply adding vitamins, minerals and essential fatty acids to the diet of 231 young offenders at a maximum security institution in Aylesbury caused a 26 per cent reduction in offences.

The well-designed, scientific trial was organised by Bernard Gesch, director of Natural Justice, a research charity set up to investigate the social and physical causes of crime.

Gesch says the human brain, like any other part of the body, requires adequate nourishment to function normally.

Although the brain makes up only two per cent of our body mass, it consumes around 20 per cent of available energy and to use this energy, it needs a range of essential nutrients.

If we don't obtain enough of these from our diet, the regulation of brain neurotransmitters, such as serotonin, is potentially affected.

This, in turn, might influence the choices we make and, crucially, the way we behave without us even knowing.

It would be naive to believe anti-social and criminal acts are purely due to eating and drinking junk but one wonders what might have become of the 231 young men had their brains and bodies been adequately or even optimally nourished.

Ironically, some of them are receiving healthier meals than they are normally used to while in HM's establishment.

But even in these cases, a moderate boost in vitamins, minerals and essential fatty acids measurably decreased the incidence of offences.

In this particular study, the greatest reduction was for serious offences, including violence, which fell by 37 per cent.

Following the spectacular results of the prison study, Gesch and colleagues are hoping for funding so they can replicate them in three other prisons in Great Britain.

He says: "Clinical studies suggest nutrition is cheap, humane and highly effective at reducing antisocial behaviour. Most importantly, people's positive potential might be realised if such an approach is taken at a time when criminal justice resources are under stress."

It is evident that political slogans and standard treatment programmes in prisons do little to reform violent criminals.

There have been major changes to diets in the past 50 years without real consideration for their impact on the brain. If reinstating healthier diets produces better results with offenders, it's worth investing in nutrition as this may ultimately mean fewer victims.

Bernard Gesch will be speaking about diet, crime and anti-social behaviour at the Children's Mental Health conference on October 9 in London.

For details, call 0870 161 3505.

Martina is a qualified nutritional therapist at the Crescent Clinic of Complementary Medicine, 37 Vernon Terrace, Brighton (01273 202221), the Dolphin House Clinic, Brighton 01273 324790). Email her at: martina@thehealthbank.co.uk