Understanding and Preventing Violence, Volume 2: Biobehavioral Influences (1994)
Chapter: HYPOGLYCEMIA, DIET, AND VIOLENT BEHAVIOR
Although studies suggest differences between violent and nonviolent offenders, sample sizes have been relatively small, and findings should be viewed as preliminary. Nevertheless, brain imaging is clearly a new field that has enormous potential for addressing questions concerning altered brain structure and function in violent offenders. For example, PET studies would be capable of directly assessing differential effects of alcohol administration on brain glucose metabolism in violent and nonviolent offender groups, and could help address the issue of whether some violent offenders constitute a subgroup that is particularly susceptible to the disinhibitory effects of alcohol on specific brain areas. Studies that combine both MRI and PET techniques are clearly desirable in that assessments of both structure and function would allow more complete statements to be made with regard to brain dysfunction in violence. Studies that combine brain imaging assessment with neuropsychologic, cognitive-psychophysiologic, and hormonal assessments in violent and nonviolent subjects would allow us to address the potentially important interactions between different biologic systems in predisposing to violence.
HYPOGLYCEMIA, DIET, AND VIOLENT BEHAVIOR
Some studies have observed that violent offenders, particularly those with a history of alcohol abuse, are characterized by reactive hypoglycemia (Virkkunen, 1986). Although there have been no demonstrations to date that violent individuals are hypoglycemic at the time of the commission of violence, it is possible that low blood glucose levels (hypoglycemia) could be conducive to aggressive behavior. Increased irritability is one symptom of hypoglycemia (Marks, 1981), and this could be the first step in the development of a full-blown aggressive outburst. Anthropologic studies, studies of aggressive personality in "normal" subjects, and experimental studies in animals all support a link between hypoglycemia and aggression (Venables and Raine, 1987). Acute symptoms of hypoglycemia are reported as maximal at 11.00–11.30 a.m. (Marks, 1981), and this time corresponds to peaks in assaults on both staff and other inmates in prison, both of which reach their maximum at 11.00–11.30 a.m. (Davies, 1982).
A number of studies have claimed that dietary changes aimed at reducing sugar consumption reduce institutional antisocial behavior in juvenile offenders, but these studies have methodological weaknesses that preclude drawing any firm conclusions at the present time (see Kanarek, in this volume). There is also some
