Cocoa flavanols improve peakVO₂ and exercise capacity in a randomized double blinded clinical trial in healthy...

Background: Loss of functional capacity is one of the hallmarks in cardiovascular aging. Cocoa flavanols (CF) exert favorable effects on endothelial function, blood pressure, and inflammation. These cardiovascular health markers worsen with increasing age and limit functional exercise capacity. Aim: To investigate the effect of CF on cardiorespiratory-fitness in healthy elderly people. Methods: In a randomized, double-masked, placebo-controlled, parallel-group dietary intervention trial, 68 healthy elderly people (55-79 years, 28 female) received either 500 mg of CF or a nutrient-matched control capsule twice a day for 30 days. Primary endpoint was defined as peak oxygen consumption (VO₂) in a cardiopulmonary exercise test (CPET). Secondary endpoints were oxygen pulse (VO₂ per heart rate (HR)), resting blood pressure (BP), and resting vascular function. Results: After 30 days of CF intake peakVO₂ increased by 190 ml min^-1 (95% CI 1-371 ml min^-1) and peakVO₂ per kg by 2.5 ml (min kg)^-1 (95% CI 0.30-4.2 ml (min kg)^-1). O₂-pulse increased by 1.7 ml (95% CI 0.29-3.2 ml) and max exercise capacity by 9.6 W (95% CI 2.1-17.7 W). CF decreased resting systolic and diastolic BP by 5.4 mmHg (95% CI -10.7 to -0.1 mmHg) and 2.9 mmHg (95% CI -5.5 to -0.4 mmHg), respectively. Flow-mediated vasodilation (FMD) increased by an absolute 1.3% (95% CI 0.76-1.79%) in the CF group. Indexes of pulmonary function were not affected. No changes for primary and secondary endpoints were detected in control. Conclusion: CF substantially improve markers of cardiorespiratory fitness in healthy elderly humans highlighting their potential to preserve cardiovascular health with increasing age.