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 ± 8.4 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. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02130141.

Favorable effects of berry consumption on platelet function, blood pressure, and HDL cholesterol.

BACKGROUND: Berries are a particularly rich source of polyphenols. They also contain other bioactive substances, such as vitamin C. Previous studies indicated that the consumption of polyphenol-rich foods (eg, cocoa, tea, and red wine) may induce beneficial changes in pathways related to cardiovascular health. Whether the consumption of berries has similar effects is unknown. OBJECTIVE: We aimed to investigate the effects of berry consumption on hemostatic function, serum lipids, and blood pressure (BP). DESIGN: Middle-aged unmedicated subjects (n = 72) with cardiovascular risk factors consumed moderate amounts of berry or control products for 8 wk in a single-blind, randomized, placebo-controlled intervention trial. RESULTS: Berry consumption inhibited platelet function as measured with a platelet function analyzer (using collagen and ADP as platelet activator) [changes: 11% and -1.4% in the berry and control groups, respectively; P = 0.018, analysis of covariance (ANCOVA)]. Plasma biomarkers of platelet activation, coagulation, and fibrinolysis did not change during the intervention. Serum HDL-cholesterol concentrations increased significantly more (P = 0.006, ANCOVA) in the berry than in the control group (5.2% and 0.6%, respectively), but total cholesterol and triacylglycerol remained unchanged. Systolic BP decreased significantly (P = 0.050, ANCOVA); the decrease mostly occurred in subjects with high baseline BP (7.3 mm Hg in highest tertile; P = 0.024, ANCOVA). Polyphenol and vitamin C concentrations in plasma increased, whereas other nutritional biomarkers (ie, folate, tocopherols, sodium, and potassium) were unaffected. CONCLUSION: The consumption of moderate amounts of berries resulted in favorable changes in platelet function, HDL cholesterol, and BP. The results indicate that regular consumption of berries may play a role in the prevention of cardiovascular disease.

Consumption of chokeberry (Aronia mitschurinii) products modestly lowered blood pressure and reduced low-grade inflammation in patients with mildly elevated blood pressure.

Previous studies suggest that consumption of chokeberries may improve cardiovascular disease risk factor profiles. We hypothesized that chokeberries (Aronia mitschurinii) have beneficial effects on blood pressure, low-grade inflammation, serum lipids, serum glucose, and platelet aggregation in patients with untreated mild hypertension. A total of 38 participants were enrolled into a 16-week single blinded crossover trial. The participants were randomized to use cold-pressed 100% chokeberry juice (300 mL/d) and oven-dried chokeberry powder (3 g/d), or matched placebo products in random order for 8 weeks each with no washout period. The daily portion of chokeberry products was prepared from approximately 336 g of fresh chokeberries. Urinary excretion of various polyphenols and their metabolites increased during the chokeberry period, indicating good compliance. Chokeberries decreased daytime blood pressure and low-grade inflammation. The daytime ambulatory diastolic blood pressure decreased (-1.64 mm Hg, P = .02), and the true awake ambulatory systolic (-2.71 mm Hg, P = .077) and diastolic (-1.62 mm Hg, P = .057) blood pressure tended to decrease. The concentrations of interleukin (IL) 10 and tumor necrosis factor α decreased (-1.9 pg/mL [P = .008] and -0.67 pg/mL [P = .007], respectively) and tended to decrease for IL-4 and IL-5 (-4.5 pg/mL [P = .084] and -0.06 pg/mL [P = .059], respectively). No changes in serum lipids, lipoproteins, glucose, and in vitro platelet aggregation were noted with the chokeberry intervention. These findings suggest that inclusion of chokeberry products in the diet of participants with mildly elevated blood pressure has minor beneficial effects on cardiovascular health.

Bioavailability of various polyphenols from a diet containing moderate amounts of berries.

Berries are a rich source of various polyphenols. The objective of this study was to investigate the bioavailability of polyphenols from berries. Middle-aged subjects (n = 72) consumed moderate amounts of berry or control products for 8 weeks in a randomized, placebo-controlled dietary intervention trial. Average intake of berries was 160 g/day (bilberries, lingonberries, black currants, and chokeberries). Plasma and urine polyphenols were analyzed by GC-MS and HPLC and berry polyphenols by HPLC. The total intake of polyphenols was 837 mg/day. Plasma quercetin, p-coumaric acid, 3-hydroxyphenylacetic acid, caffeic acid, protocatechuic acid, vanillic acid, homovanillic acid, and 3-(3-hydroxyphenyl)propionic acid increased significantly from the baseline in the berry group compared to the control group (p < 0.05). The urinary excretion of quercetin, p-coumaric acid, and 3-hydroxyphenylacetic acid increased significantly in the berry group compared to the control group (p < 0.05). In conclusion, a number of polyphenols are bioavailable from a diet containing moderate amounts of blue and red berries.