Theobromine consumption does not improve fasting and postprandial vascular function in overweight and obese subjects

Backgound Theobromine, a component of cocoa, may favorably affect conventional lipid-related cardiovascular risk markers, but effects on flow-mediated dilation (FMD) and other vascular function markers are not known. Objective To evaluate the effects of 4-week theobromine consumption (500 mg/day) on fasting and postprandial vascular function markers. Design In a randomized, double-blind crossover study, 44 apparently healthy overweight ( N = 30) and obese ( N = 14) men and women with low HDL-C concentrations, consumed daily 500 mg theobromine or placebo for 4 weeks. After 4 weeks, FMD, peripheral arterial tonometry (PAT), augmentation index (AIx), pulse wave velocity (PWV), blood pressure (BP) and retinal microvasculature measurements were performed. These measurements were carried out under fasting conditions and 2.5 h after a high-fat mixed meal challenge. Results 4-week theobromine consumption did not change fasting vascular function markers, except for a decrease in central AIx (cAIx, − 1.7 pp, P = 0.037) and a trend towards smaller venular calibers (− 2 µm, P = 0.074). Consuming a high-fat mixed meal decreased FMD (0.89 pp, P = 0.002), reactive hyperemia index (RHI, − 0.30, P