 |
|
|
Dutch prison study: Nutrients reduce behavior problems
Young male adult offenders who received nutritional supplements committed significantly fewer incidents of aggression and rule-breaking than those taking a placebo, according to a new Dutch study.
In the randomized, double-blind, placebo-controlled study, Ap Zaalberg and colleagues evaluated more than 200 offenders between the ages of 18 and 25 who were incarcerated in eight Dutch prisons. Half of the group received a placebo, while the other half received supplements containing 25 vitamins and minerals and several essential fatty acids. Participants who took the supplements or placebos for at least one full month were included in the results.
The researchers’ data showed a significant reduction in reported incidents among prisoners taking the supplements compared to those receiving the placebo. “When expressed in proportional differences, the decrease on this measure was impressive,” they say, “with a reduction of 34% in the experimental group against a 14% increase in the control group.” However, the researchers did not see differences between the active and placebo groups in measurements of aggression or psychiatric symptoms.
The findings of Zaalberg and colleagues are consistent with an earlier report by Bernard Gesch and colleagues, who found that prisoners receiving nutritional supplements committed 26% fewer offences than those taking placebos. In Gesch’s study, prisoners taking supplements committed 37% fewer serious offences compared to baseline levels. Like Zaalberg and colleagues, Gesch and colleagues did not detect changes in the prisoners’ self-reported aggression or psychological symptoms. Zaalberg comments that the actual count of incidents “may be a more ‘concrete’ outcome measurement” than personal reports.
The researchers conclude that “the prospect of influencing aggression and rule-breaking behavior with nutrients in moderate doses is important enough to warrant future research.” They add, “This is particularly true as adequate supplementation may also have beneficial effects on mental health and cognitive functioning.”
A third large-scale study, conducted by Oxford University researchers, is currently investigating the effects of nutritional supplements on 1,000 prisoners in three facilities. The three-year study will end in 2011.
-----
“Effects of nutritional supplements on aggression, rule-breaking, and psychopathology among young adult prisoners,” Ap Zaalberg, Henk Nijman, Erik Bulten, Luwe Stroosma, and Cees van der Staak, Aggressive Behavior, Vol. 35, 2009, 1-10. Address: Ap Zaalberg, WODC, Ministry of Justice, P.O. Box 20301, NL-2500, EH, The Hague, The Netherlands, a.zaalberg@minjus.nl.
|
|
