Dutch study: dietary supplements cut prisoner infractions

Researchers in the Netherlands report that prisoners given nutritional supplements showed less aggressive behavior than those who did not take the supplements.

The Dutch Ministry of Justice’s National Agency of Correctional Institutions carried out the study in cooperation with the Radboud University of Nijmegen. More than 200 juvenile and adult offenders from eight institutions participated on a volunteer basis, with half receiving supplements containing vitamins, minerals, and essential fatty acids and the other half taking a placebo. The prisoners used the products for one to three months.

The study found a 34 percent reduction in the rate of disciplinary offending in the group taking the supplements compared to a 13 percent increase in the unsupplemented group, for an overall difference of 47 percent between the two groups. No differences in overall aggression or psychiatric complaints were seen between the groups.

Bernard Gesch, whose own study of British prisoners also showed a drop in disciplinary offending when prisoners received supplements (see related article, Crime Times, 2002, Vol. 8, No. 3, Page 1), comments, “There are now three sizable double-blind randomized, controlled trial studies in the U.S., U.K., and now the Netherlands all showing significant reduction in disciplinary offending…. These results seem to confirm the need for a policy review to consider the role of diet in criminal justice as this approach seems to be low cost and highly effective, and the only risk is better health.”