An infant's diet, known to be important for early mental development, may also play a significant role in the risk for mental illness or criminal behavior in later life, suggests a new study.
The study, published in the current issue of the American Journal of Psychiatry, found that children aged three to five years old who took part in an 'enrichment program', including healthy diet, exercise and pre-school education, were less likely to develop personality disorders and antisocial behavior in their late teens, and were also less likely to show criminal behavior at age 23, than control subjects.
The benefits of the enrichment were much stronger in children who were poorly nourished before the study started, reported the researchers, suggesting that good nutrition was the active ingredient in the prevention program.
"Parents often feel helpless as though there's nothing they can do to ward off mental illness," said Adrian Raine, a psychology professor at the University of South Carolina and leader of the project. "Our results clearly show there are several proactive steps parents can take."
In the study, among the first to look at ways of preventing psychotic disorders, 83 three-year-olds from the island of Mauritius were fed hot meals, given two-and-a-half hours of daily exercise and treated to intense cognitive stimulation over a two-year period in a pre-school setting.
Compared to 355 children who received no special treatment, the enriched group at 17 years of age had 31.9 per cent reduction in schizotypal personality, a precursor to schizophrenia. Those who received the intervention also had a 27.9 per cent reduction in antisocial behavior problems at age 17.
And the crime rate was cut by 35 per cent at age 23.
When the study was launched, the two sets of children did not differ in their nutritional status. The children in the control group were fed a traditional Mauritian diet, high in starches, including mostly bread and rice.
The enriched group was fed fish, chicken or mutton and salad for lunch. They were given milk breaks and morning fruit juices. They also had an afternoon nap.
"This suggests that proper nutrition, exercise and cognitive stimulation in preschool very likely will create better behavior 20 years later," Raine said. "Perhaps what is critical is the establishment of good habits early on in life - when the brain is growing. The implication for society is that we may have identified some of the building blocks of schizophrenia and crime."
This is not first time that diet has been connected to criminal behaviour. Previous research in the UK has investigated the impact of vitamins and other nutrients on behaviour of criminals. The current study suggests that government investment in children's health can benefit society as a whole.
"One of the best changes society could make is to invest in the early years of childhood, when children's brains are more amenable to change. A small investment now will reap big returns later," added Raine.