Cocoa flavanols improve cardiorespiratory fitness in older adults Original paper

In this randomized controlled study, supplementation with cocoa flavanols increased cardiorespiratory fitness and improved blood pressure in a group of older adults without apparent health conditions.

The effect of cocoa flavonols on cardiorespiratory fitness and cardiovascular disease risk factors in older adults without apparent health conditions.

The primary outcome was VO₂peak. The secondary outcomes included endothelial function and blood pressure.

68 older adults without apparent health conditions (ages 55–79; 28 women and 40 men).

In this 30-day randomized controlled trial, the participants received a high-flavanol cocoa extract supplement (1,000 mg of cocoa extract including 160 mg of (−)-epicatechin) or a placebo daily.

Before and after supplementation, the participants completed a cardiopulmonary exercise test (CPET) on a bicycle ergometer to assess cardiorespiratory fitness (VO₂peak). Endothelial function was measured using flow-mediated dilation (FMD).

Absolute VO₂peak increased by 190 milliliters per minute (mL/min) in the cocoa group, and relative VO₂peak increased by 2.51 milliliters of oxygen per kilogram per minute (mL/kg/min); absolute and relative VO₂peak did not change in the placebo group.

Systolic and diastolic blood pressure decreased in the cocoa group by 5.4 and 2.9 mmHg, respectively, and FMD increased by 1.28%; neither of these outcomes changed in the placebo group.

Although changes were observed in the cocoa group and not the placebo group, the authors didn’t report whether the values for cardiorespiratory fitness, blood pressure, or FMD were better in the cocoa group in comparison with the control group at the end of the intervention, which reduces our confidence in the findings.

The participants in this study were described as not having any health conditions, but a baseline systolic/diastolic blood pressure of 138/81 puts them in the category of stage I hypertension. Thus, the blood-pressure-lowering effects of cocoa flavanols may not be generalizable to people with normal (120/80) blood pressure.