Atherosclerosis progressively occurs with increasing age in the general population. So far most dietary intervention studies with flavanols were performed over short time frames and in small groups of young healthy and older patients with manifest cardiovascular disease, respectively. Vascular health is defined as absence of vascular disease and the presence of optimal parameters that determine the development and progression of arteriosclerosis (endothelial function, blood pressure, plasma lipids, and glucose). It is not clear whether flavanols can improve parameters of vascular health, most importantly endothelial function, when given repetitively to healthy middle aged and which factors affect the efficacy of flavanol interventions.

Inclusion Criteria:

• male, age 35-60 years, healthy
• female, age 35-60 years, healthy

Exclusion Criteria:

• diabetes mellitus, acute inflammation, arrhythmia, active malignancy, terminal renal failure, signs, symptoms or medication indicative of manifest cardiovascular disease (CAD, PAD, CVD)