Gesch, C.B., Hammond, S.M., Hampson, S.E., Eves, A., Crowder, M.J. (2002) British Journal of Psychiatry 181 22-8.
BACKGROUND: There is evidence that offenders consume diets lacking in essential nutrients and this could adversely affect their behaviour.
AIMS: To test empirically if physiologically adequate intakes of vitamins, minerals and essential fatty acids cause a reduction in antisocial behaviour.
METHOD: Experimental, double-blind, placebo-controlled, randomised trial of nutritional supplements on 231 young adult prisoners, comparing disciplinary offences before and during supplementation.
RESULTS: Compared with placebos, those receiving the active capsules committed an average of 26.3% (95% CI 8.3-44.33%) fewer offences (P=0.03, two-tailed). Compared to baseline, the effect on those taking active supplements for a minimum of 2 weeks (n=172) was an average 35.1% (95% CI 16.3-53.9%) reduction of offences (P
CONCLUSIONS: Antisocial behaviour in prisons, including violence, are reduced by vitamins, minerals and essential fatty acids with similar implications for those eating poor diets in the community.
This study shows striking effects of dietary supplements in reducing antisocial behaviour by young offenders. Its importance is difficult to overstate, although the findings will obviously need replication.
In January 2008, a replication study was initiated by a team of scientists based at Oxford University. This will involve up to 1000 offenders at three UK prisons, with completion expected in 2012.
Update February 2010. Similar results have been reported by scientists at the Dutch Ministry of Justice. This was a smaller study with some methodological limitations, but the pattern of results is obviously encouraging for the ongoing UK replication study.