Cocoa flavanols improve peakVO ₂ and exercise capacity in a randomized double blinded clinical trial in healthy elderly

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. Methods In a randomized, double-masked, placebo-controlled, parallel-group dietary intervention trial, 68 healthy elderly (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 (VO 2 ) in a cardiopulmonary exercise test (CPET). Secondary endpoints were oxygen pulse (VO 2 /heart rate (HR)), resting blood pressure (BP), and resting vascular function. Results After 30 days of CF intake peakVO 2 increased by 190 ml/min (95% CI 1-371 ml/min) and peakVO 2 /kg by 2.5 ml/(min*kg) (95% CI 0.30-4.2 ml/(min*kg)). O 2 -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 - -0.1 mmHg) and 2.9 mmHg (95% CI (-) 5.5-(-) 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.