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Effects of Combining Cocoa and Soy in Type 2 Diabetes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT01754662
Recruitment Status : Completed
First Posted : December 21, 2012
Last Update Posted : November 21, 2013
Information provided by (Responsible Party):

Study Description
Brief Summary:

Diabetes is an increasingly common condition affecting millions of people world wide. The cornerstone of treatment is lifestyle that includes looking at the way how people eat. It is known that food containing compounds called polyphenols can reduce the risk of heart disease risk in people with diabetes. Two foods that are rich sources of polyphenols are cocoa (epicatechins) and soy (isoflavones). Previous studies have shown the benefits of these foods in the diets of people with diabetes. It has also been shown that soy isoflavones and cocoa polyphenols can improve the mood in certain groups of patients.

What is not known is whether there is any extra benefit of combining soy protein and isoflavones with cocoa.

The aim of the study is to look at the modification of cardiovascular risk by soy and/or cocoa in patients with type 2 diabetes, alone or in combination.

Condition or disease Intervention/treatment
Type 2 Diabetes Dietary Intervention Dietary Supplement: Soy protein Dietary Supplement: Isoflavones Dietary Supplement: Cocoa Dietary Supplement: Placebo

Detailed Description:
  1. General information about the study

    The target number of participants is 100. All participants are patients with type 2 diabetes on diet alone or metformin treatment. Participants will be asked to eat two soy bars daily for 8 weeks. The length of the study is 10 weeks and involves 4 visits at the Diabetes Research Centre in Hull, UK.

    The bars will contain:

    • soy protein alone, or
    • soy protein with additional isoflavones, or
    • soy protein with cocoa, or
    • soy protein with isoflavones and cocoa, or
    • placebo bars without soy protein, isoflavones or cocoa.

    The study is randomised (a computer based allocation schema will be used to decide which bars the participant will need to consume). Participants have the same 20% chance to be participant of any of the above groups. The study is placebo-controlled (there is one arm of placebo bars without soy protein, additional isoflavones or cocoa). The study is double-blind (neither the participants or the research team will know which bars they will take).

  2. Study-specific procedures

Visit 1 (week 0). Non-fasting visit. Interested participants discuss the study with a member of the study team who will explain each aspect of the study, following which informed consent will be then obtained. Subsequently, blood pressure, weight, height and waist circumference will be measured, medical history and list of medication are recorded, and blood is taken to determine eligibility. A dietitian will explain about eating a normal diet and the foods we would like the participants to avoid during the study. Vegetarian patients may include too much soy in the diet and for this reason they will not be able to take part in the study. All participants will be non smokers.

Visit 2 (week 2)and Visit 4 (week 10). Fasting visits. Fasting blood is taken and the EndoPAT is performed. Weight, height and waist circumference measurement performed. The EndoPAT test takes between 20-30 minutes. The first box of study bars is dispensed during visit 2. Participants need to consume two bars daily. All remaining uneaten bars and empty wrappers will be collected during visit 4.

Visit 3 (week 6). Non-fasting visit. Height, weight, abdominal circumference, blood pressure are measured. Second box of study bars is dispensed.

Participants are asked to complete a one week food diary and a three day hunger questionnaire before the fasting blood tests. The food diary includes mood rating scales to assess the effect of the consumption of the bars on mood. Participants need to complete these prior to Visit 2 and visit 4.

Participants have 24 hours blood pressure measurement prior to Visit 2 and Visit 4.

24 hours urine collection also takes place prior to visit 2 and visit 4.

3. Optional test incorporated into the study: Body Volume Index measurement Based on participants preference, Body Volume Index measurement is offered as a complementary tool to assess body shape and weight.

Study Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 84 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: A Pilot Study Investigating the Effects of the Combined Effects of Cocoa and Soy Polyphenols in a Soy Protein Matrix on Insulin Resistance and Cardiovascular Disease Risk in Type 2 Diabetes - A Randomised Placebo-Controlled Double-Blind Parallel Study
Study Start Date : October 2011
Primary Completion Date : June 2013
Study Completion Date : June 2013

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Experimental: Soy protein with isoflavones and cocoa
Soy protein with isoflavones and cocoa bars. 2 bars daily for 8 weeks.
Dietary Supplement: Soy protein
2 bars daily for 8 weeks.
Dietary Supplement: Isoflavones
2 bars daily for 8 weeks.
Dietary Supplement: Cocoa
2 bars daily for 8 weeks.
Experimental: Soy protein alone with cocoa
Soy protein alone with cocoa with no isoflavones. 2 bars daily for 8 weeks.
Dietary Supplement: Soy protein
2 bars daily for 8 weeks.
Dietary Supplement: Cocoa
2 bars daily for 8 weeks.
Experimental: Soy protein with soy isoflavones
Soy protein with isoflavones bar. 2 bars daily for 8 weeks.
Dietary Supplement: Soy protein
2 bars daily for 8 weeks.
Dietary Supplement: Isoflavones
2 bars daily for 8 weeks.
Experimental: Soy protein alone
Soy protein alone without soy isoflavone or cocoa polyphenol. 2 bars daily for 8 weeks.
Dietary Supplement: Soy protein
2 bars daily for 8 weeks.
Placebo Comparator: Placebo
Placebo bar without soy protein, isoflavones or cocoa polyphenols. 2 bars daily for 8 weeks
Dietary Supplement: Placebo

Outcome Measures

Primary Outcome Measures :
  1. Insulin resistance, lipid profile [ Time Frame: 8 weeks ]
    Soy with isoflavones and cocoa polyphenols have a greater impact on insulin resistance, lipid parameters in type 2 diabetes than seen with soy protein alone, soy protein with isoflavones and soy protein with cocoa polyphenols.

Secondary Outcome Measures :
  1. Cardiovascular risk [ Time Frame: 8 weeks ]
    Soy with isoflavones reduces cardiovascular risk as measured by fasting lipids and blood pressure

  2. Isoflavones [ Time Frame: 8 weeks ]
    Soy with isoflavones increases plasma isoflavones

  3. Endothelial function [ Time Frame: 8 weeks ]
    Soy and cocoa improves endothelial function

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   45 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients with type 2 diabetes controlled by diet or metformin only
  • Stable medication history for 3 months prior to screening visit
  • Age 45-80

Exclusion Criteria:

  • Patients with concurrent illness or any medication (especially antibiotics)3 months prior to enrollment that would effect the study results based on investigator's judgement
  • Patients not wishing to allow disclosure to their GPs
  • Pre-menopausal women or on hormone replacement therapy
  • HbA1c >9% at screening
  • Patients with known food allergies
  • Smokers
  • Vegans and vegetarians
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01754662

United Kingdom
Michael White Diabetes Centre
Hull, North Humberside, United Kingdom, HU3 2RW
Sponsors and Collaborators
Hull and East Yorkshire Hospitals NHS Trust
University of Hull
Principal Investigator: Stephen Atkin University of Hull
More Information


Responsible Party: Stephen L Atkin, Professor, University of Hull
ClinicalTrials.gov Identifier: NCT01754662     History of Changes
Other Study ID Numbers: R1188
First Posted: December 21, 2012    Key Record Dates
Last Update Posted: November 21, 2013
Last Verified: November 2013

Keywords provided by Stephen L Atkin, University of Hull:
Type 2 diabetes
Cardiovascular risk
Endothelial function
Insulin resistance

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases