Dose and Response to Cocoa (DARC): A Randomized Double-Blind Controlled Trial
Complete Project
Title:
Dose and Response to Cocoa (DARC): A Randomized Double-Blind Controlled Trial
Status:
Completed
Topic:
Cardiovascular Health / Endothelial Function*
Funding Source:
The Hershey Company
Funding Period:
2012-2014
Study Design:
Randomized, controlled, modified Latin square parallel design
Purpose:
To compare the effects of two daily doses of cocoa consumption (five vs. 10 grams of cocoa powder) over an 8-week period on risk factors for cardiovascular disease in adults with stage one hypertension. Our own prior studies had shown that a 10-gram dose of cocoa powder could lead to improved blood vessel function in overweight adults. For this study, we wanted to learn whether the cardiovascular benefits of cocoa-containing products would vary when comparing this dose to a smaller dose (five grams) of cocoa powder, and whether this would affect blood pressure. Because chocolate is a popular dietary source of cocoa but is high in calories and often high in added sugar, we sought to determine a minimum cocoa dose that could provide heart-healthy benefits.
Further Study Details:
The PRC recruited 60 men and women age 18-75 years who met the study criteria listed below. Boston Medical Center recruited 60 patients who met the same criteria.
Findings:
When we analyzed the data for the entire group of participants, we found that daily consumption of either 5 or 10 grams of cocoa-containing products did not significantly improve blood pressure, endothelial function, arterial stiffness, lipid profile, glucose levels, or insulin resistance. When we analyzed the data on a sub-group basis (based on the types of blood pressure prescription medications that participants happened to be taking prior to, and during, the study), we found that the extent to which adding cocoa-containing products to their usual diets appeared to reduce their cardiovascular disease risk seemed to depend on which prescription medications that they were taking to control their blood pressure.
Eligibility:
Men and women age 18-75 years with stage 1 hypertension (high blood pressure, with systolic pressure ranging from 140 to 159 and diastolic pressure ranging from 90 to 99) who were taking no more than one blood pressure medication, and who had a body mass index (BMI) of less than 35.
Yale-Griffin Prevention Research Center