Chocolate Against Stress

40 grams of dark chocolate per day reduces the urinary excretion of the stress hormone cortisol and it almost normalizes the stress related differences in energy metabolism and gut microbial activities between participants with low and high anxiety traits.

You are what you eat, it has been described how dietary preferences is associated with metabolic processes in healthy subjects. How does dark chocolate, by some considered to be a very healthy, affect the human metabolism? A number of studies have shown cardiovascular benefits of eating flavanol rich cocoa. In a recent post I discussed the possible underlying mechanisms of these cardioprotective properties of chocolate. The mechanism of action of chocolate at the molecular level are poorly understood. In this recent study the metabolic changes due to chocolate in healthy subjects was examined with metabonomics.

we have used proton nuclear magnetic resonance (1H NMR) spectroscopy and mass spectrometry (MS) as complementary analytical platforms for monitoring metabolic changes associated with a daily intake of 40 g of dark chocolate over a period of 2 weeks in the urine and blood plasma of 30 individuals (11 males, 19 females) classified according to their self-reported anxiety trait.

Already after one week metabolic changes were evident in the metabolic profiles of participants compared to the baseline analyses. This became more significant after two weeks of dark chocolate at 40 grams per day. The metabolic changes in both endogenous and gut microbial metabolism was evident.

Comparing the groups with low and high anxiety traits revealed a decreased level of urinary stress hormone levels in the participants with high level trait anxiety after two weeks of dark chocolate. This suggest potential beneficial implications of dark chocolate consumption for reduction of mental and/or physical stress and improvement of the metabolic response to stress. 40 grams can be considered a low dose, still waiting for proof of dose response relationship, what do you think?
Martin, F., Rezzi, S., Peré-Trepat, E., Kamlage, B., Collino, S., Leibold, E., Kastler, J., Rein, D., Fay, L., & Kochhar, S. (2009). Metabolic Effects of Dark Chocolate Consumption on Energy, Gut Microbiota, and Stress-Related Metabolism in Free-Living Subjects Journal of Proteome Research, 8 (12), 5568-5579 DOI: 10.1021/pr900607v