A study of 931 men and women in the San Diego area showed that people who ate an average of 8.4 servings of chocolate per month tested positive for possible depression, while people who ate only 5.4 servings per month did not test positive. People who ate 11.8 servings per month tested positive for probable major depression, a more severe form of the condition. The participants were not taking any antidepressant drugs at the time of the study.
The findings were based on questionnaires about the participants’ diets and emotional well-being and were published in the April 26 issue of Archives of Internal Medicine.
Researchers led by Natalie Rose, MD, of the University of California at San Diego, defined a medium-sized serving as one small bar or 28 grams (1 ounce) of chocolate candy.The participants’ ages ranged from 20 to 85; 80% of the group was white; 70% were male; more than half were college graduates; and most were not severely overweight or obese — the average body mass index was 27.8.
The results suggest several possible relationships between eating chocolate and mood.
“First, depression could stimulate chocolate cravings as ‘self-treatment’ if chocolate confers mood benefits, as has been suggested in recent studies of rats,” Rose and colleagues write. “Second, depression may stimulate chocolate cravings for unrelated reasons, without a treatment benefit of chocolate (in our sample, if there is a ‘treatment benefit,’ it did not suffice to overcome the depressed mood on average). Third, from cross-sectional data the possibility that chocolate could causally contribute to depressed mood, driving the association, cannot be excluded.”
Inflammation may also play a role in depression and chocolate cravings. It is possible that the biochemical effects of chocolate may be counteracted by the ingredients found in consumer chocolate products, such as artificial trans fat, which may, in turn, lower omega-3 fatty acid production. Omega-3 fatty acids, which are abundant in fish, have been shown to produce an antidepressive effect.
Rose and her team noted that the intake of caffeine, fat, carbohydrates, and energy in the participants’ diets had no significant correlation with the participants’ mood, suggesting there may be something specific about the relationship between chocolate and one’s state of mind.
“Future studies are required to elucidate the foundation of the association and to determine whether chocolate has a role in depression, as cause or cure,” the authors conclude.