flavan-3-ol and Hypertension

The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).. This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.. With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.. A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.. The trial is registered at http://clinicaltrials.gov (identifier: NCT01690676 ). Registered 25th May 2012.

Topics: Adult; Aged; Brachial Artery; Catechin; Chlorogenic Acid; Cross-Over Studies; Dose-Response Relationship, Drug; Double-Blind Method; Endothelium, Vascular; Female; Flavonoids; Humans; Hypertension; Male; Malus; Middle Aged; Tannins; Vasodilation

This study aimed to evaluate the protective role of ground raspberry seeds (RBS) as a source of polyphenols and essential fatty acids on blood plasma enzymatic antioxidant status, lipid profile, and endothelium-intact vasodilation during physiological and pathological conditions. Young normotensive Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) at ten weeks of age were fed with either a control diet or were supplemented with added 7% RBS for six weeks (

Topics: Acetylcholine; Animals; Aspartate Aminotransferases; Atherosclerosis; Cardiovascular Diseases; Catalase; Cyclooxygenase 2; Dietary Fiber; Dietary Supplements; Disease Models, Animal; Epoprostenol; Flavonoids; Hydrolyzable Tannins; Hypertension; Liver; Male; Nitric Oxide Synthase Type II; Rats, Inbred SHR; Rats, Inbred WKY; Rubus; Vasodilation

Flavan-3-ols are a group of bioactive compounds that have been shown to improve vascular function in intervention studies. They are therefore of great interest for the development of dietary recommendation for the prevention of cardio-vascular diseases. However, there are currently no reliable data from observational studies, as the high variability in the flavan-3-ol content of food makes it difficult to estimate actual intake without nutritional biomarkers. In this study, we investigated cross-sectional associations between biomarker-estimated flavan-3-ol intake and blood pressure and other CVD risk markers, as well as longitudinal associations with CVD risk in 25,618 participants of the European Prospective Investigation into Cancer (EPIC) Norfolk cohort. High flavan-3-ol intake, achievable as part of an habitual diet, was associated with a significantly lower systolic blood pressure (- 1.9 (- 2.7; - 1.1) mmHg in men and - 2.5 (- 3.3; - 1.8) mmHg in women; lowest vs highest decile of biomarker), comparable to adherence to a Mediterranean Diet or moderate salt reduction. Subgroup analyses showed that hypertensive participants had stronger inverse association between flavan-3-ol biomarker and systolic blood pressure when compared to normotensive participants. Flavanol intake could therefore have a role in the maintenance of cardiovascular health on a population scale.

Topics: Aged; Blood Pressure; Cross-Sectional Studies; Eating; Feeding Behavior; Female; Flavonoids; Heart Disease Risk Factors; Humans; Hypertension; Male; Melanesia; Middle Aged; Nutritional Physiological Phenomena

We studied the short-term antihypertensive effect of flavan-3-ols (-)-epicatechin, (+)-catechin and (-)-catechin, in spontaneously hypertensive rats (SHR). Plasma metabolites and the corresponding plasma antioxidant capacity were determined. All the assayed flavan-3-ols decreased systolic blood pressure (SBP) in SHR. Their antihypertensive effects were less pronounced than that of Captopril (50 mg kg(-1)) and were not shown in normotensive Wistar-Kyoto rats. 6 mg kg(-1) (-)-epicatechin caused the maximum decrease in SBP. The maximum effects of the catechin monomers were observed post-administration of 0.5 mg kg(-1) of flavan-3-ols, (-)-catechin being the least effective among the three assayed compounds. Glucuronide and methyl glucuronide metabolites were obtained in the flavan-3-ol treated SHR, but it was not possible to relate the antihypertensive effect of the assayed flavan-3-ols with a concrete plasma metabolite or with their antioxidant effect. In conclusion, the studied flavan-3-ols could be responsible for the antihypertensive effect of cocoa products.

Topics: Animals; Antihypertensive Agents; Antioxidants; Blood Pressure; Cacao; Captopril; Catechin; Flavonoids; Glucuronides; Hypertension; Male; Rats; Rats, Inbred SHR; Rats, Inbred WKY

A low sodium diet has often been implicated in the protection of low blood pressure populations from hypertension, but several other dietary factors, including those as yet unidentified, may also be involved. The Kuna Indians of Panama are free of hypertension and cardiovascular disease, but this is changing with migration to urban areas. We compared the indigenous diet of Kuna Indians living on remote islands in Panama (Ailigandi), whose lifestyle is largely hunter-gatherer, with those who have moved to a suburb of Panama City (Vera Cruz). Between April and October 1999, members of a Kuna research team administered a 118-item food frequency questionnaire to133 adult Kuna from Ailigandi and 183 from Vera Cruz. Single 24-hour urine collections and nonfasting blood samples were obtained. The Kuna in Ailigandi reported consuming a 10-fold higher amount of cocoa-containing beverages, 4 times the amount of fish, and twice the amount of fruit as urban Kuna (P<0.05 by t test). Salt added was ample among those living in Ailigandi and Vera Cruz according to both self-report (7.1+/-1.1 and 4.6+/-0.3 tsp weekly) and urinary sodium levels (177+/-9 and 160+/-7 mEq Na/g creatinine), respectively. The low blood pressure of island-dwelling Kuna does not seem to be related to a low salt diet. Among dietary factors that varied among migrating Kuna, the notably higher intake of flavanol-rich cocoa is a potential candidate for further study.

Topics: Acculturation; Adult; Animals; Beverages; Biflavonoids; Cacao; Catechin; Diet; Diet Surveys; Female; Fishes; Flavonoids; Fruit; Humans; Hypertension; Indians, Central American; Male; Middle Aged; Panama; Proanthocyanidins; Sodium, Dietary; Vegetables

Diet patterns are widely recognized as contributors to hypertension. Widely studied potential contributors include intake of sodium, potassium, magnesium, calcium, soluble fiber, omega-3 fatty acids, alcohol, protein, and calories. We add to that list the effect of dietary flavanols present in certain cocoas, which have sufficient activity on vascular nitric oxide to influence blood pressure control. Kuna Indians who live on islands near Panama have little age-related rise in blood pressure or hypertension. On migration to Panama City, blood pressure rises with age, and the frequency of essential hypertension matches urban levels elsewhere. We have identified a specific food that probably makes an important contribution to cardiovascular status. Island-dwelling Kuna drink more than 5 cups of flavanol-rich cocoa per day and incorporate that cocoa into many recipes. Mainland Kuna ingest little cocoa, and what they take is commercially available and flavanol-poor. The flavanol-rich cocoa activates nitric oxide synthase in vitro and in intact humans in the doses that the Kuna employ. Vasodilator responses to flavonoid-rich cocoa are prevented or reversed by the arginine analog, N-nitro-L-arginine methyl ester. Island-dwelling Kuna have a 3-fold larger urinary nitrate:nitrite than do Mainland dwellers. As endothelial dysfunction is central to current thinking on cardiovascular pathophysiology, a food that enhances endothelial function could have broad implications. The list of candidate conditions that might be influenced is impressive, ranging from atherosclerosis and diabetes mellitus to hypertension and preeclampsia, to vascular dementias and end-stage renal disease. The next decade will be interesting.

Topics: Aging; Blood Pressure; Blood Vessels; Cacao; Enzyme Activation; Flavonoids; Humans; Hypertension; Indians, Central American; Nitric Oxide Synthase; Panama