Feeling crabby? Maybe you should put the onion rings down.
According to a new study in the journal PLoS ONE, there may be a link between eating dietary trans fatty acids -- known as trans fats, and found in foods from French fries to some cake mixes -- and being irritable and aggressive.
"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," study researcher Dr. Beatrice Golomb, M.D., Ph.D., an associate professor at the University of California San Diego department of medicine, said in a statement.
That's because "the detrimental effects of trans fats may extend beyond the person who consumes them to affect others," she added.
For the study, Golomb and colleagues examined the dietary information of 945 men and women, and also conducted behavioral assessments on them. The behavioral survey included their life histories of aggression, how they handled conflict, their self-rated impatience and irritability levels, and their score on an "overt aggression" scale.
Researchers found that greater trans fats intake seemed to predict whether a person was more aggressive. The finding held true even after taking into account factors like sex, age and ethnicity.
Aside from this new finding, there are plenty of other reasons to avoid trans fats. The Mayo Clinic explained that trans fat -- which is made when hydrogen is added to vegetable oil, to help foods last longer -- increases "bad" cholesterol levels and lowers "good" cholesterol levels, increasing heart disease risk.
And a past study, published last year in the journal Neurology, showed that people with high blood trans fats levels perform worse on cognitive tests, and they have less total brain volume. That study involved 100 elderly people who live in California and Oregon.
"It's clear that trans fats are bad -- both for your heart and now, we see, for your brain," the researcher of that study, Dr. Gene Bowman of Oregon Health & Science University, told HuffPost Food. "So I would recommend that people stay away from all trans fats. If you aren't sure whether something has them, just look at the ingredients; if there's vegetable shortening, partially hydrogenated anything... just put it down. That's the big message here."
Fortunately, a lot of restaurants and food brands have eliminated trans fats from their products. But the not-so-good news is that the fats are still lurking in many of the foods we eat. Check out this slideshow from our partner Health.com for foods that may still contain trans fats: