According to Golomb et al 2012 some studies found omega-3 fatty acids to be associated with increased agreeableness and reduced impulsivity. 
Dietary trans fatty acids (dTFA) inhibit the production of omega-3 fatty acids, which experimentally have been shown to reduce aggression toward self, others, and objects assessing Overt Aggression Scale Modified, Life History of Aggression, Conflict Tactics Scale, impatience and irritability. The authors found that eating more trans fats increased aggression and irritability.
High trans-fat consumption increases heart disease and certain cancers and behavioural distress. Supporting the public health initiatives to limit trans-fat consumption.
 Golomb BA, Evans MA, White HL, Dimsdale JE: Trans fat consumption and aggression.PLoS One. 2012;7(3):e32175.