Study leader by Dr. Beatrice Golomb, an associate professor in the University of California, San Diego, Department of Medicine, said the study involved nearly 1,000 men and women.
Dietary trans fatty acids are primarily products of hydrogenation, which makes unsaturated oils solid at room temperature. They are present at high levels in margarine, shortening and prepared foods, Golomb said.
Golomb and colleagues measured factors such as a life history of aggression, conflict tactics and self-rated impatience and irritability. They used an "overt aggression" scale that tallies recent aggressive behaviors.
"We found that greater trans fatty acids were significantly associated with greater aggression, and were more consistently predictive of aggression and irritability, across the measures tested, than the other known aggression predictors that were assessed," Golomb said in a statement. "If the association between trans fats and aggressive behavior proves to be causal, this adds further rationale to recommendations to avoid eating trans fats, or including them in foods provided at institutions like schools and prisons, since the detrimental effects of trans fats may extend beyond the person who consumes them to affect others."
The findings were published in the journal PLoS ONE.