 |
|
Chocolate and Blood Pressure in Elderly Individuals With Isolated Systolic Hypertension
To the Editor: Chocolate may have beneficial cardiovascular effects, possibly due to cocoa polyphenols.1 Experiments in animals suggest that plant polyphenols decrease blood pressure (BP)2; however, evidence from human clinical trials is lacking. We examined whether dark chocolate (polyphenol-rich chocolate [PRC]) may lower BP in individuals with mild isolated hypertension.
Methods
We conducted a randomized crossover trial in 13 otherwise healthy individuals (6 men and 7 women, aged 55-64 years, with body mass index of 21.9-26.2 [calculated as weight in kilograms divided by the square of height in meters]) with recently diagnosed and untreated stage 1 mild isolated systolic hypertension (mean [SD] systolic BP, 153.2 [3.9] mm Hg; mean [SD] diastolic BP, 83.8 [3.5] mm Hg). After a cocoa-free run-in phase of 7 days, participants were randomly assigned to receive 14 consecutive daily doses of either 100-g dark PRC bars containing 500 mg of polyphenols and 480 kcal of energy (Ritter Sport Halbbitter, Alfred Ritter, Waldenbuch, Germany), or 14 days of 90-g white chocolate (polyphenol-free chocolate [PFC]) bars that also contained 480 kcal and similar amounts of cocoa butter, macronutrients, fiber, electrolytes, and vitamins (Milka Weisse Schokolade, Kraft Foods, Bremen, Germany). After a cocoa-free washout phase of 7 days, participants were crossed over to the other condition. Participants were asked to substitute the chocolate bars for foods of similar energy and macronutrient composition. Overall diet during the study period was assessed by reports of daily food intake and by measurement of body weight, plasma concentrations of lipids and glucose, and urinary excretion of sodium, potassium, and nitrogen at the run-in phase and after each intervention period.
The BP was recorded daily, in a blinded fashion, with participants in a seated position, 12 hours post-dose, in the left upper arm with a validated oscillometer (Omron HEM 722C, Omron, Mannheim, Germany). A systolic BP of more than 170 mm Hg or a diastolic BP of more than 100 mm Hg at a single visit was necessary for referral for antihypertensive pharmacological treatment. At the end of the study participants were referred to their physician for further monitoring and management of BP. We received approval for our study from the ethics committee of the Medical Faculty of the University of Cologne; all participants gave written informed consent.
Results
Participants had significantly lower systolic and diastolic BPs within 10 days of beginning PRC, but this effect was not seen during the PFC period (Figure 1). At the end of the 14-day PRC intervention, mean (SD) systolic BP had declined by 5.1 (2.4) mm Hg (P<.001; paired 2-tailed t test) and mean (SD) diastolic BP by 1.8 (2.0) mm Hg (P = .002; paired 2-tailed t test) compared with PFC. After discontinuation of PRC consumption, BP returned to preintervention values within 2 days. Heart rate was not affected by either treatment. There were no sex differences in the effects of chocolate on BP. None of the participants reached the predefined threshold that would have required antihypertensive drug therapy. Daily energy intake and macronutrient composition remained stable throughout the study. Body mass index, 24-hour urinary excretion of sodium, potassium, and total nitrogen, as well as fasting plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and glucose were not significantly different between the run-in phase and the postintervention periods.
Comment
A calorie-balanced increase in consumption of dark chocolate may favorably affect BP in previously untreated elderly hypertensive individuals. Control meals using PFC differed from PRC meals only by the lack of cocoa solids. Plant polyphenols are major constituents of the cocoa solids,3 have significant bioavailability,4 and appear to be responsible for the reductions in BP. The long-term clinical effects, however, remain unknown.
Dirk Taubert, MD, PhD
Department of Pharmacology
Reinhard Berkels, PhD;
Renate Roesen, PhD;
Wolfgang Klaus, MD, PhD
Medical College of the University of Cologne
Cologne, Germany
1. Keen CL. Chocolate: food as medicine/medicine as food. J Am Coll Nutr. 2001;20(5 suppl):436S-439S, 440S-442S.
FREE FULL TEXT
2. Diebolt M, Bucher B, Andriantsitohaina R. Wine polyphenols decrease blood pressure, improve NO vasodilatation, and induce gene expression. Hypertension. 2001;38:159-165.
FREE FULL TEXT
3. Luna F, Crouzillat D, Cirou L, Bucheli P. Chemical composition and flavor of Ecuadorian cocoa liquor. J Agric Food Chem. 2002;50:3527-3532.
PUBMED
4. Holt RR, Lazarus SA, Sullards MC, et al. Procyanidin dimer B2 [epicatechin-(4beta-8)-epicatechin] in human plasma after the consumption of a flavanol-rich cocoa. Am J Clin Nutr. 2002;76:798-804.
FREE FULL TEXT
Letters Section Editor: Stephen J. Lurie, MD, PhD, Senior Editor.
JAMA. 2003;290:1029-1030.
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
|
Blood Pressure Is Reduced and Insulin Sensitivity Increased in Glucose-Intolerant, Hypertensive Subjects after 15 Days of Consuming High-Polyphenol Dark Chocolate
Grassi et al.
J. Nutr. 2008;138:1671-1676.
ABSTRACT
| FULL TEXT
Acute dark chocolate and cocoa ingestion and endothelial function: a randomized controlled crossover trial
Faridi et al.
Am. J. Clin. Nutr. 2008;88:58-63.
ABSTRACT
| FULL TEXT
A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults
Crews et al.
Am. J. Clin. Nutr. 2008;87:872-880.
ABSTRACT
| FULL TEXT
Daily Consumption of a Dark Chocolate Containing Flavanols and Added Sterol Esters Affects Cardiovascular Risk Factors in a Normotensive Population with Elevated Cholesterol
Allen et al.
J. Nutr. 2008;138:725-731.
ABSTRACT
| FULL TEXT
Favorable effects of berry consumption on platelet function, blood pressure, and HDL cholesterol
Erlund et al.
Am. J. Clin. Nutr. 2008;87:323-331.
ABSTRACT
| FULL TEXT
Effects of Low Habitual Cocoa Intake on Blood Pressure and Bioactive Nitric Oxide: A Randomized Controlled Trial
Taubert et al.
JAMA 2007;298:49-60.
ABSTRACT
| FULL TEXT
Effect of Cocoa and Tea Intake on Blood Pressure: A Meta-analysis
Taubert et al.
Arch Intern Med 2007;167:626-634.
ABSTRACT
| FULL TEXT
Red wine polyphenols prevent angiotensin II-induced hypertension and endothelial dysfunction in rats: Role of NADPH oxidase
Sarr et al.
Cardiovasc Res 2006;71:794-802.
ABSTRACT
| FULL TEXT
Cocoa intake, blood pressure, and cardiovascular mortality: the zutphen elderly study.
Buijsse et al.
Arch Intern Med 2006;166:411-417.
ABSTRACT
| FULL TEXT
(-)-Epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans
Schroeter et al.
Proc. Natl. Acad. Sci. USA 2006;103:1024-1029.
ABSTRACT
| FULL TEXT
Chocolate Consumption and Incidence of Hypertension
Alonso et al.
Hypertension 2005;46:e21-e22.
FULL TEXT
Acute Consumption of Flavanol-Rich Cocoa and the Reversal of Endothelial Dysfunction in Smokers
Heiss et al.
J Am Coll Cardiol 2005;46:1276-1283.
ABSTRACT
| FULL TEXT
Reply to CJ Kelly
Grassi et al.
Am. J. Clin. Nutr. 2005;82:487-488.
FULL TEXT
Cocoa Reduces Blood Pressure and Insulin Resistance and Improves Endothelium-Dependent Vasodilation in Hypertensives
Grassi et al.
Hypertension 2005;46:398-405.
ABSTRACT
| FULL TEXT
Review: Health Effects of Cocoa Flavonoids
Lamuela-Raventos et al.
Food Science and Technology International 2005;11:159-176.
ABSTRACT
Cocoa, diabetes, and hypertension: should we eat more chocolate?
Fraga
Am. J. Clin. Nutr. 2005;81:541-542.
FULL TEXT
Short-term administration of dark chocolate is followed by a significant increase in insulin sensitivity and a decrease in blood pressure in healthy persons
Grassi et al.
Am. J. Clin. Nutr. 2005;81:611-614.
ABSTRACT
| FULL TEXT
Bioavailability and bioefficacy of polyphenols in humans. II. Review of 93 intervention studies
Williamson and Manach
Am. J. Clin. Nutr. 2005;81:243S-255S.
ABSTRACT
| FULL TEXT
Cocoa polyphenols and inflammatory mediators
Sies et al.
Am. J. Clin. Nutr. 2005;81:304S-312S.
ABSTRACT
| FULL TEXT
The Polymeal: a more natural, safer, and probably tastier (than the Polypill) strategy to reduce cardiovascular disease by more than 75%
Franco et al.
BMJ 2004;329:1447-1450.
ABSTRACT
| FULL TEXT
Pentameric Procyanidins Isolated from Theobroma cacao Seeds Selectively Downregulate ErbB2 in Human Aortic Endothelial Cells
Kenny et al.
Exp. Biol. Med. 2004;229:255-263.
ABSTRACT
| FULL TEXT
|
P<.001; 
P = .04; and 
P = .03, indicating significant differences in blood pressure between diets with polyphenol-rich or polyphenol-free chocolate, adjusted to a baseline blood pressure difference of zero (paired 2-tailed t tests, individual P values are adjusted for multiple comparisons by the method of Holm). All other P values are >.05. Error bars indicate SEM.