Long term cocoa ingestion leads to an increased resistance against UV-induced erythema and a lowered transepidermal water loss. AIM OF THE STUDY: To investigate the acute effects of a single dose of cocoa rich in flavanols on dermal microcirculation. METHODS: In a crossover design study, 10 healthy women ingested a cocoa drink (100 ml) with high (329 mg) or low (27 mg) content of flavanols. The major flavanol monomer in both drinks was epicatechin, 61 mg in the high flavanol, and 6.6 mg in the low flavanol product per 100 ml. Dermal blood flow and oxygen saturation of hemoglobin were examined by laser Doppler flowmetry and spectroscopically at 1 mm skin depth at t = 0, 1, 2, 4, and 6 h. At the same time points, plasma levels of total epicatechin (free compound plus conjugates) were measured by means of HPLC. RESULTS: Subsequent to the intake of high flavanol cocoa, dermal blood flow was significantly increased by 1.7-fold at t = 2 h and oxygen saturation was elevated 1.8-fold. No statistically significant changes were found upon intake of low flavanol cocoa. Maximum plasma levels of total epicatechin were observed 1 h after ingestion of the high flavanol cocoa drink, 11.6 +/- 7.4 nmol/l at baseline, and 62.9 +/- 35.8 nmol/l at 1 h. No change of total epicatechin was found in the low flavanol group. CONCLUSION: Flavanol-rich cocoa consumption acutely increases dermal blood flow and oxygen saturation.
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Dietary antioxidants contribute to endogenous photoprotection and are important for the maintenance of skin health. In the present study, 2 groups of women consumed either a high flavanol (326 mg/d) or low flavanol (27 mg/d) cocoa powder dissolved in 100 mL water for 12 wk. Epicatechin (61 mg/d) and catechin (20 mg/d) were the major flavanol monomers in the high flavanol drink, whereas the low flavanol drink contained 6.6 mg epicatechin and 1.6 mg catechin as the daily dose. Photoprotection and indicators of skin condition were assayed before and during the intervention. Following exposure of selected skin areas to 1.25 x minimal erythemal dose (MED) of radiation from a solar simulator, UV-induced erythema was significantly decreased in the high flavanol group, by 15 and 25%, after 6 and 12 wk of treatment, respectively, whereas no change occurred in the low flavanol group. The ingestion of high flavanol cocoa led to increases in blood flow of cutaneous and subcutaneous tissues, and to increases in skin density and skin hydration. Skin thickness was elevated from 1.11 +/- 0.11 mm at wk 0 to 1.24 +/- 0.13 mm at wk 12; transepidermal water loss was diminished from 8.7 +/- 3.7 to 6.3 +/- 2.2 g/(h x m2) within the same time frame. Neither of these variables was affected in the low flavanol cocoa group. Evaluation of the skin surface showed a significant decrease of skin roughness and scaling in the high flavanol cocoa group compared with those at wk 12. Dietary flavanols from cocoa contribute to endogenous photoprotection, improve dermal blood circulation, and affect cosmetically relevant skin surface and hydration variables.
