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NCT Number: NCT00421499

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

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.

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Key information

Conditions

Hypertension Cardiovascular Diseases Vascular Diseases

Age range

55 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Department of Pharmacology, University of Cologne

Cologne, 50931, Germany

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

dark chocolate

Drug

Primary outcomes

  1. changes in systolic and diastolic blood pressure

Secondary outcomes

  1. plasma levels of bioactive nitric oxide, 8-isoprostane, cocoa polyphenols

Sponsors and collaborators

Lead sponsor

University of Cologne

Other

Registry information

Official study 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

Important dates

Study start
2005
Study completion
2005
First posted
Jan 12, 2007
Registry last updated
Jan 12, 2007

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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