LAUSANNE, Switzerland—Eating half an ounce of dark chocolate a day for two weeks reduced levels of stress hormones in the bodies of people feeling highly stressed and partially corrected other stress-related biochemical imbalances, according to a new study published online in ACS’ Journal of Proteome Research.
Researchers studied 30 participants who were classified in low and high anxiety traits using validated psychological questionnaires. Biological fluids (urine and blood plasma) were collected during three test days at the beginning, mid-time and at the end of a two-week study. Subjects with higher anxiety trait showed a distinct metabolic profile indicative of a different energy homeostasis (lactate, citrate, succinate, trans-aconitate, urea, proline), hormonal metabolism (adrenaline, DOPA, 3-methoxy-tyrosine) and gut microbial activity (methylamines, p-cresol sulfate, hippurate). Dark chocolate reduced the urinary excretion of the stress hormone cortisol and catecholamines and partially normalized stress-related differences in energy metabolism (glycine, citrate, trans-aconitate, proline, β-alanine) and gut microbial activities (hippurate and p-cresol sulfate).
Researchers identified reductions in stress hormones and other stress-related biochemical changes in volunteers who rated themselves as highly stressed and ate dark chocolate for two weeks. The study provides strong evidence that a daily consumption of 40 grams during a period of two weeks is sufficient to modify the metabolism of healthy human volunteers.