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Effects of Cocoa Intake on Blood Pressure in Elderly Individuals With Mild Hypertension

This study has been completed.
Information provided by:
University of Cologne Identifier:
First received: January 11, 2007
Last updated: NA
Last verified: January 2007
History: No changes posted

Regular intake of cocoa-containing foods is linked to a considerably lower cardiovascular and all-cause mortality in observational studies. Short-term intervention studies indicate that high doses of cocoa improve endothelial function and reduce blood pressure (BP), but the clinical impact of long-term intake of small dietary amounts of cocoa on BP and the underlying BP lowering mechanisms are unclear. We hypothesized that cocoa consumption lowers blood pressure by augmentation of the circulating vasodilative nitric oxide (NO) pool due to the action of the cocoa polyphenols at the vascular endothelium.

To test this hypothesis, we will conduct a randomized single-blind, parallel group study in subjects with mild essential hypertension to evaluate the effects of polyphenol-rich dark chocolate versus polyphenol-free white chocolate on blood pressure and plasma levels of cocoa phenols, circulating bioactive nitric oxide, and plasma markers of oxidative stress. After a 7 day cocoa-free run-in period, 44 subjects will be 1:1 randomized to receive over 18 weeks daily doses of either dark chocolate (6.3 g per day with a total of 30 mg of polyphenols and 30 kcal) or polyphenol free white chocolate (5.6 g per day with 30 kcal, containing similar amounts of macronutrients, electrolytes and vitamins). Subjects will be counseled to maintain an isocaloric diet and to abstain from other cocoa products during the study. Blood pressure and plasma parameters will be assessed in each subject after the run-in period and after 6, 12, and 18 weeks of treatment.

Condition Intervention Phase
Hypertension Drug: dark chocolate Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single
Primary Purpose: Treatment
Official Title: Randomized Controlled, Parallel Group, Single Blinded, Phase 1 Study That Investigates the Effects of Regular Daily Intake of Small Amounts of Dark or White Chocolate on Blood Pressure in Elderly Individuals With Mild Hypertension

Further study details as provided by University of Cologne:

Primary Outcome Measures:
  • changes in systolic and diastolic blood pressure

Secondary Outcome Measures:
  • plasma levels of bioactive nitric oxide, 8-isoprostane, cocoa polyphenols

Estimated Enrollment: 44
Study Start Date: January 2005
Estimated Study Completion Date: May 2005

Ages Eligible for Study:   55 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Subjects between the ages of 55 - 75 years in good general health with high normal blood pressure (between 130/80 and 140/90 mmHg) or mild hypertension (blood pressure between 140/90 and 160/100 mmHg)on no medication or nutritional supplements
  • Non-manual workers with a household income > 20,000 €/year
  • Normal plasma lipids (total plasma cholesterol < 6.18 mmol/L
  • LDL < 4.11 mmol/L
  • HDL > 0.9 mmol/L
  • Triacylglycerols < 1.8 mmol/L) and normal plasma glucose (fasting plasma glucose 4.2-6.4 mmol/L).
  • If a subject's blood pressure exceeds 170/100 mmHg on a single visit, the subject will be withdrawn from the study and referred to appropriate antihypertensive therapy.

Exclusion Criteria:

Subjects are excluded if they have:

  • Cardiovascular diseases (other than hypertension)
  • Diabetes mellitus
  • Hyper-/dyslipidemia
  • Gastrointestinal diseases
  • Hepatic and renal disorders
  • Pulmonary diseases
  • Coagulopathy
  • Cancer
  • Psychiatric disorders
  • Alcohol or drug dependence
  • Seizure disorders
  • History of organ transplantation
  • Surgery within the last 12 months
  • Positive tests for HIV, hepatitis B or C.

Subjects are excluded if they have:

  • A body-mass index of more than 27.5 or less than 18.5 kg/m2
  • Actively smoked tobacco within the last five years
  • Regularly use medications
  • Used any medication within the last two weeks before entry
  • Use vitamin, mineral or polyphenol supplements or functional food.

Subjects will be excluded if they are unable to give informed consent for all procedures; or subjects who are not capable or willing to appear for controlling visits.

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Please refer to this study by its identifier: NCT00421499

Department of Pharmacology, University of Cologne
Cologne, Germany, 50931
Sponsors and Collaborators
University of Cologne
Principal Investigator: Dirk Taubert Department of Pharmacology, University of Cologne
  More Information

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00421499     History of Changes
Other Study ID Numbers: ECA-02-005
Study First Received: January 11, 2007
Last Updated: January 11, 2007

Additional relevant MeSH terms:
Vascular Diseases
Cardiovascular Diseases processed this record on September 21, 2017