Flavanol-rich chocolate acutely improves arterial function and working memory performance counteracting the effects of sleep deprivation in healthy individuals.
J Hypertens. 2016 Jul ;34(7):1298-308. PMID: 27088635
BACKGROUND: Sleep deprivation is a risk factor for cardiovascular disease. Cocoa flavonoids exert cardiovascular benefits and neuroprotection. Whether chocolate consumption may mitigate detrimental effects of sleep loss on cognitive performance and cardiovascular parameters has never been studied.
AIM: We investigated the effects of flavanol-rich chocolate consumption on cognitive skills and cardiovascular parameters after sleep deprivation.
METHODS: Thirty-two healthy participants underwent two baseline sessions after one night of undisturbed sleep and two experimental sessions after one night of total sleep deprivation. Two hours before each testing session, participants were randomly assigned to consume high or poor flavanol chocolate bars. During the tests were evaluated, the Psychomotor Vigilance Task and a working memory task, office SBP and DBP, flow-mediated dilation and pulse-wave velocity.
RESULTS: Sleep deprivation increased SBP/DBP. SBP/DBP and pulse pressure were lower after flavanol-rich treatment respect to flavanol-poor treatment (SBP: 116.9 ± 1.6 vs. 120.8 ± 1.9 mmHg, respectively, P = 0.00005; DBP: 70.5 ± 1.2 vs. 72.3 ± 1.2 mmHg, respectively, P = 0.01; pulse pressure: 46.4 ± 1.3 vs. 48.4 ± 1.5 mmHg, P = 0.004). Sleep deprivation impaired flow-mediated dilation (5.5 ± 0.5 vs. 6.5 ± 0.6%, P = 0.02), flavanol-rich, but not flavanol-poor chocolate counteracted this alteration (flavanol-rich/flavanol-poor chocolate: 7.0 ± 0.6 vs. 5.0 ± 0.4%, P = 0.000001). Flavanol-rich chocolate mitigated the pulse-wave velocity increase (P = 0.001). Flavanol-rich chocolate preserved working memory accuracy in women after sleep deprivation. Flow-mediated dilation correlated with working memory performance accuracy in the sleep condition (P = 0.04).
CONCLUSION: Flavanol-rich chocolate counteracted vascular impairment after sleep deprivation and restored working memory performance. Improvement in cognitive performance could be because of the effects of cocoa flavonoids on blood pressure and peripheral and central blood flow.