02 June 2008

Fish: the new crime buster?

When they're released from prison, inmates might want to increase their intake of fish or take omega-3 supplements to curb aggressive behaviours and reduce the risk of relapse.

When they're released from prison, inmates might want to increase their intake of fish or take omega-3 supplements to curb aggressive behaviours and reduce the risk of relapse, a leading psychologist suggested last week.

"Why not try it? What would be the harm?" said Dr Adrian Raine, professor of Criminology, Psychiatry and Psychology at the University of Pennsylvania, speaking at the IV Brazilian Congress of Brain, Behaviour and Emotions.

"Omega-3 fatty acids...have been shown to improve the functioning of brains and reduce violent behaviours," he told Reuters Health. "And actually, American prisoners eat very little fish."

Criminality linked to genes?
The proposal is based on a growing, but controversial body of evidence that attributes criminality to biological factors, such as a genetically driven dysfunction in the prefrontal cortex. Biological predisposition might explain at least 50 percent of criminal behaviour, Raine estimates.

In this context, nutritional intervention in prisoners might become a "naturalistic" way of helping change brains at risk. "It might not only reduce (further) serious offending, but could also make prisoners more amenable to other treatments, such as cognitive behaviour therapy," he said.

Raine based his hypothesis upon the results of some "compelling" trials in children and adults, he said. A 2002 study conducted with 231 young English prisoners showed that taking nutritional supplements containing omega-3 fatty acids, for at least 2 weeks, was associated with a 35 percent reduction in offenses after 5 months.

In another study, conducted by Raine and published in the American Journal of Psychiatry in 2003, children aged 3 to 5 participated in an "environmental enrichment" program, including a fish-enriched diet, physical activity and cognitive stimulation. Twenty years later, it was found that the crime rate in the intervention group had been lowered by 35 percent.

A third trial, published in 2005, showed that normal 8- to-11 year-old children reduced their aggressive behaviour by taking omega-3 fatty acids supplements for only 4 months.

In addition, a 2001 cross-national ecological analysis found a direct link between seafood intake and lower murder rates.

Possible treatment for aggression
A nutritional intervention, perhaps combined with some cognitive behaviour therapy, might work not only in prisoners, but also in aggressive children and others at risk for antisocial behaviours.

"Fish oil and omega-3 fatty acids improve brain structures and attention abilities. And maybe (violent people) need better brains to learn instructions to regulate their emotions," Raine said.

Effective dosages of omega-3 or fish intake to prevent antisocial conduct or criminal relapses are unknown, but about 1 g/d of omega-3 or two to three meals of fish a week might be needed, the investigator added.

Bernard Gesch, researcher in the Department of Physiology, Anatomy and Genetics at Oxford University and director of Natural Justice, an Oxford-based research charity that investigates the social and physical causes of offending behaviour, thinks that Raine's suggestion is interesting.

"But nutrition is about balance. Many nutrients, including vitamins and minerals, have already been implicated in behavioural change when lacking in the diet. Omega-3 is but one," Gesch told Reuters Health via email.

New study underway
Gesch, lead author of the 2002 English trial that investigated the impact of nutritional supplements on the behaviour of young prisoners, said that his group is about to start a much larger study with 1 000 prisoners, funded by the Wellcome Trust.

"It will take around two years to complete. We are not only retesting to see if nutrition affects behaviour, but also to explore how it works," he said. "It is a simple approach to prevent antisocial behaviour, and the only 'risk' from a better diet is better health."

According to data from the US Department of Justice obtained for 15 states, almost 70 percent of released prisoners are re-arrested for a felony or serious misdemeanour within 3 years. Eventually, 47 percent of all former prisoners are again convicted for a crime, and 25 percent are sent to prison with a new sentence. – (Matias A. Loewy/Reuters Health)

Read more:
How food affects your mood

June 2008


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