The scattergram indicates the relationship between homicide mortality rates and seafood consumption among 26 countries. Higher rates of death due to homicide were predicted by lower rates of seafood consumption in a logarithmic regression model (r= – 0.63, p<0.0006) and in a simple regression model (r= – 0.47, p<0.01). These data suggest that insufficient intake of omega-3 fats may be one of the many factors that contribute to a greater risk mortality due to homicide. Joe Hibbeln, M.D, “Seafood Consumption and Mortality from Homicide: A Cross-national Ecological Analysis, In The World Review of Nutrition and Dietetics, 4th Congress of the International Society for the Study of Lipids and Fatty Acids. Karger??Press, 2000, In Press.
Virkkunen et. al. reported that impulsive and violent offenders had lower plasma concentrations of DHA and higher concentrations of 22:5n6 than non-impulsive offenders and healthy controls. Virkkunen ME, Horroboin DF, Jenkins DK, Manku MS: Plasma phospholipid essential fatty acids and prostaglandins in alcoholic, habitually violent and impulsive offenders. Biol Psychiatry 1987; 22: 1087-1096.
A double blind placebo controlled intervention trial with 2 grams of DHA/ day, gave reductions in a measure of hostility among Japanese students under the stress of University exams. Hamazaki T, Sawazaki S, Itomura M, Asaoka E, Nagao Y, Nishimura N, Yazawa K, Kuwamori T, Kobayashi M: The effect of docosahexaenoic acid on aggression in young adults. A placebo-controlled double-blind study. J Clin Invest 1996; 97: 1129-1133.
Weidner et. al. also noted a decrease in measures of hostility in a five-year dietary intervention study that increased fish intake. Weidner G, Connor SL, Hollis JF, Connor WE: Improvements in hostility and depression in relation to dietary change and cholesterol lowering. Ann Int Med 1992; 117: 820-823.
It is reasonable to assume that measures of the affective state of hostility are in continuum that includes violent behavior in the most extreme cases. Among healthy volunteers, low concentrations of CSF 5-HIAA correlated with low concentrations of plasma DHA. Perhaps an insufficient status of tissue EPA and DHA may increase predisposition to impulsive behaviors. % Hibbeln JR, Linnoila M, Umhau JC, Rawlings R, George DT, Salem Jr. N: Essential fatty acids predict metabolites of serotonin and dopamine in cerebrospinal fluid among healthy control subjects, and early- and late-onset alcoholics. Biol Psychiatry 1998; 44: 235-242.
Recent studies have both offered and contested the proposition that lowering plasma cholesterol by diet and medications increases suicide, homicide, and depression. Epidemiological studies show lower n 3 fatty acid consumption correlates with higher rates of depression, consistent with a well established positive correlation between depression and coronary artery disease. Long chain n 3 polyunsaturate deficiency may also contribute to depressive symptoms in alcoholism, multiple sclerosis, and postpartum depression. Perhaps adequate long chain polyunsaturated fatty acids, particularly docosahexaenoic acid, may reduce the development of depression just as n 3 polyunsaturated fatty acids may reduce coronary artery disease. -Hibbeln JR and Salem N Jr. Dietary polyunsaturated fatty acids and depression: when cholesterol does not satisfy. Am J Clinical Nutr 1995; 62: 1-9; -Hibbeln JR and Salem N Jr. Risks of cholesterol-lowering therapies. Biological Psychiatry 1996; 40: 7: 686-687. % Hibbeln JR, Umhau JC, George DT, and Salem N Jr. Do Plasma Polyunsaturates predict Hostility and Violence? World Rev Nutr Diet 1996; 82: 175-186. %Hibbeln JR, Salem Jr. N: Dietary polyunsaturated fatty acids and depression: when cholesterol does not satisfy. Am J Clin Nutr 1995; 62: 1-9.
Violent subjects had significantly higher lifetime violence and hostility ratings and lower concentrations of CSF 5 HIAA than nonviolent subjects, Plasma docosahexaenoic acid was negatively correlated with CSF 5 HIAA only among violent subjects. Prospective dietary intervention trials will be required to determine if increasing dietary intake of docosahexaenoic acid will increase or decrease either CSF 5 HIAA concentrations or impulsive and violent behaviors. Hibbeln JR; Umhau JC; Linnoila M; George DT; Ragan PW; Shoaf SE; Vaughan MR; Rawlings R; Salem N. A replication study of violent and nonviolent subjects: Cerebrospinal fluid metabolites of serotonin and dopamine are predicted by plasma essential fatty acids. BIOLOGICAL PSYCHIATRY 1998; 44: 243 249.
Among recent suicide attempters, low plasma concentrations of EPA predicted increased severity of psychometric measures closely related to suicide; greater guilt, greater impulsivity, greater scores of the suicide assessment scale and greater severity in most sub-scales of the Comprehensive Psychopathological Rating Scale. Hibbeln JR, Enstrom G, Majchrzak S, Salem Jr. N, Traskman-Benz L. Suicide attempters and PUFAS: lower plasma eicosapentaenoic acid alone predicts greater psychopathology. 4th Congress of the International Society for the Study of Lipids and Fatty Acids 2000; P-5-28:
For 1,767 subjects in Northern Finland, frequent fish consumption (twice per week or more) related to significantly lower risk of reporting depressive symptoms (odds ratio = 0.63, p < 0.03) and of reporting suicidal thinking (odds ratio = 0.57, p, 0.04). Tanskanen A, Hibbeln JR, Hintikka J, Haatainen K, Honkalampi K, Viinamaki H: Fish consumption, depression , and suicidality in a general population. 4th Congress of the International Society for the Study of Lipids and Fatty Acids, 2000; O-7-A4.
There is no silver bullet capable of neutralizing the biological or psychological triggers that set an individual on a path toward violence. Indeed, it’s still unclear how much animal studies can reveal about our own capacity for violence. But ultimately, researchers are bound to converge on a common goal: Deeper knowledge of the biology of violence will help social scientists match violence-prone individuals with intervention programs that can steer them onto a path toward conciliation and respect for the sanctity of life. Richard Stone and Katrina Kelner Violence: No Silver Bullet. Science 2000 July 28; 289: 569
Emotion is normally regulated in the human brain by a complex circuit consisting of the orbital frontal cortex, amygdala, anterior cingulate cortex, and several other interconnected regions. There are both genetic and environmental contributions to the structure and function of this circuitry. Richard J. Davidson, Katherine M. Putnam, Christine L. Larson. Dysfunction in the Neural Circuitry of Emotion Regulation–A Possible Prelude to Violence. Science 2000; 289: 591-594.