Dark chocolate and reduced snack consumption in mildly hypertensive adults: an intervention study

Background: Several studies have shown that cocoa and cocoa-containing foods have the potential to lower blood pressure and improve endothelial function. Most of the studies reporting the beneficial effects of dark chocolate on blood pressure have been short (<= 4 weeks). The aim of the present 8-wks (weeks) study was to assess the effects of regular consumption of dark chocolate during a reduced snack consumption intervention on blood pressure and other cardiovascular risk factors in mildly hypertensive individuals. Design: This was a randomized, controlled, cross-over trial involving 22 adults (8 women, 14 men), aged 33-64 y, BMI 27.7 +/- 3.7 kg/m(2) with mild hypertension. During the intervention period (8-wks) the participants reduced the intake of habitual snacks and replaced them with dark chocolate (49 g/day). In the control period, they only reduced the snacks without any added chocolate. Data (blood lipid profile, glucose, insulin, 24 h blood pressure) was collected in the beginning and end of both periods (intervention and control), and some variables also in the run-in and run-out periods (weight, body fat percentage, blood pressure, arterial stiffness index, diet and physical activity). Results: Daily consumption of dark chocolate had no effects on 24 h blood pressure, resting blood pressure (mean +/- SD, pre 142 +/- 11.5/89 +/- 4 mmHg vs. post 142 +/- 14.2/88 +/- 9.4 mmHg in systolic and diastolic blood pressure, respectively) or arterial stiffness (mean +/- SD, pre 7.68 +/- 0.88 vs. post 7.76 +/- 0.89). Weight was reduced by 1.0 +/- 2.2 kg during the control (reduced snack only) period, but was unchanged while eating chocolate (p < 0.027 between the treatments). Conclusion: The data collected in this study indicates that inclusion of dark chocolate daily in the diet had no significant effects on blood pressure or other cardiovascular risk factors during a reduced snack period.