Purpose: Preventive health effects of coffee could have a widespread impact on public health. Green coffee has more phenols than roasted, and thus is healthier, although with less acceptable organoleptic properties. Therefore, the effects of regularly consuming a green/roasted coffee blend (35/65) on the main components of MetS in humans were evaluated.
Methods: A crossover, randomized, controlled study was performed in 25 normocholesterolaemic and 27 hypercholesterolaemic men and women aged 18-45 years with BMI 18-25 kg/m2. Three servings/day of the blend, providing 510.6 mg hydroxycinnamic acids and 121.2 mg caffeine/day, were consumed versus a control drink, during 8 weeks each. Polyphenol and methylxanthine-rich foods were restricted along the study. At the beginning (baseline) and end of the control and coffee interventions, blood samples were collected and glucose, HDL-cholesterol, triglycerides, insulin, leptin, plasminogen activator inhibitor-1 (PAI-1), resistin and visfatin were analysed; waist circumference, %body fat, and blood pressure were measured and dietary records and physical activity questionnaires completed.
Results: Systolic and diastolic blood pressure decreased (p = 0.001 and p < 0.001, respectively) in both groups as well as %body fat (p = 0.001) which may be related to the lower leptin (p = 0.001), PAI-1 (p < 0.001) and resistin (p = 0.034) levels in the two groups after coffee consumption. Glucose concentration (p = 0.030) and insulin resistance (p = 0.011; HOMA-IR) also decreased, as well as triglyceride levels (p = 0.017), so that the reduction was much greater in the hypercholesterolaemics (group effect, p = 0.027).
Conclusion: Regular consumption of the green/roasted coffee blend may be recommended to healthy and hypercholesterolaemic subjects to prevent MetS, as it produces positive effects on blood pressure, glucose and triglyceride levels.
Keywords: Coffee; Diabetes; Hydroxycinnamic acids; Hypertension; Metabolic syndrome; Weight loss.