At the forefront of a field known as
"neurocriminology," Adrian Raine of the University of Pennsylvania
has long studied the interplay between biology and environment when it comes to
antisocial and criminal behavior. With strong physiological evidence that
disruption to the emotion-regulating parts of the brain can manifest in violent
outbursts, impulsive decision-making and other behavioral traits associated
with crime, much of Raine's research involves looking at biological
interventions that can potentially ward off these behavioral outcomes.
A new study by Raine now suggests that omega-3, a fatty acid
commonly found in fish oil, may have long-term neurodevelopmental effects that
ultimately reduce antisocial and aggressive behavior problems in children.
He is a Penn Integrates Knowledge Professor with
appointments in the School of Arts & Sciences and the Perelman School of
Medicine.
Along with Raine, the study featured Jill Portnoy a graduate
student in the Department of Criminology, and Jianghong Liu, an associate
professor in the Penn School of Nursing. They collaborated with Tashneem
Mahoomed of Mauritius' Joint Child Health Project and Joseph Hibbeln of the
National Institute on Alcohol Abuse and Alcoholism.
It was published in the Journal of Child Psychology and
Psychiatry.
When Raine was a graduate student, he, his advisor and
colleagues conducted a longitudinal study of children in the small island
nation of Mauritius. The researchers tracked the development of children who
had participated in an enrichment program as 3-year-olds and also the
development of children who had not participated. This enrichment program had
additional cognitive stimulation, physical exercise and nutritional enrichment.
At 11 years, the participants showed a marked improvement in brain function as
measured by EEG, as compared to the non participants. At 23, they showed a 34
percent reduction in criminal behavior.
Raine and his colleagues were interested in teasing apart
the mechanisms behind this improvement. Other studies suggested the nutritional
component was worth a closer look.
"We saw children who had poor nutritional status at age
3 were more antisocial and aggressive at 8, 11 and 17," Raine said.
"That made us look back at the intervention and see what stood out about
the nutritional component. Part of the enrichment was that the children
receiving an extra two and a half portions of fish a week."
Other research at the time was beginning to show that
omega-3 is critical to brain development and function.
"Omega-3 regulates neurotransmitters, enhances the life
of a neuron and increases dendritic branching, but our bodies do not produce
it. We can only get it from the environment," Raine said.
Research on the neuroanatomy of violent criminals suggested
this might be a place to intervene. Other brain-imaging researchers have shown
that omega-3 supplementation increases the function of the dorsolateral
prefrontal cortex, a region Raine found to have higher rates of damage or
dysfunction in criminal offenders.
Raine's new study featured a randomized controlled trial
where children would receive regular omega-3 supplements in the form of a juice
drink. One hundred children, aged 8 to 16, would each receive a drink
containing a gram of omega-3 once a day for six months, matched with 100
children who received the same drink without the supplement. The children and
parents in both groups took a series of personality assessments and
questionnaires at the start.
After six months, the researchers administered a simple
blood test to see if the children in the experimental group had higher levels
of omega-3 than those in the controls. They also had both parents and children
take the personality assessments. Six months after that, the researchers had
parents and children take the assessment again to see if there were any lasting
effects from the supplements.
The assessments had parents rate their children on
"externalizing" aggressive and antisocial behavior, such as getting
into fights or lying, as well as "internalizing" behavior, such as
depression, anxiety and withdrawal. Children were also asked to rate themselves
on these traits.
While the children's self-reports remained flat for both
groups, the average rate of antisocial and aggressive behavior as described by
the parents dropped in both groups by the six-month point. Critically, however,
those rates returned to the baseline for the control group but remained lowered
in the experimental group, at the 12-month point.
"Compared to the baseline at zero months," Raine
said, "both groups show improvement in both the externalizing and
internalizing behavior problems after six months. That's the placebo effect.
"But what was particularly interesting was what was
happening at 12 months. The control group returned to the baseline while the
omega-3 group continued to go down. In the end, we saw a 42 percent reduction
in scores on externalizing behavior and 62 percent reduction in internalizing
behavior."
At both the six- and 12-month check-ins, parents also
answered questionnaires about their own behavioral traits. Surprisingly,
parents also showed an improvement in their antisocial and aggressive behavior.
This could be explained by the parents taking some of their child's supplement,
or simply because of a positive response to their child's own behavioral
improvement.
The researchers caution that this is still preliminary work
in uncovering the role nutrition plays in the link between brain development
and antisocial behavior. The changes seen in the one-year period of the
experiment may not last, and the results may not be generalizable outside the
unique context of Mauritius.
Beyond these caveats, however, there is reason to further
examine omega-3's role as a potential early intervention for antisocial
behavior.
"As a protective factor for reducing behavior problems
in children," Liu said, "nutrition is a promising option; it is
relatively inexpensive and can be easy to manage."
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