Dark Chocolate and Glucose Levels in Diabetes

Impact of Dark Chocolate Consumption on Glucose Levels of People With Diabetes

Diabetes is a growing concern in the world with an estimated 9.3% of adults, ages 20-79, with it in 2019, type 2 diabetes accounting for 90% of this total. A common recommendation for individuals with diabetes is to limit sugars and sweets as it may cause a high blood glucose response. As a result, chocolate is often avoided due to the sugar content; though, high-polyphenol chocolate may have a beneficial effect on hyperglycaemia and vascular function. The sugar-free chocolate from Ross Chocolates is formulated with a blend of inulin, erythritol, and stevia. These alternatives to sugar are not expected to cause a significant change in blood glucose levels following consumption. The main objective of this study is to verify glucose levels before and after consumption of Ross Chocolates' blend of sweeteners dark chocolate and conventional chocolate in people with diabetes.

Study Overview

• Status: Completed
• Conditions: Type 1 Diabetes; Type 2 Diabetes
• Intervention / Treatment: Dietary supplement: Dark chocolate

Detailed Description

Individuals with type 1 or type 2 diabetes (10 participants each) will consume a Ross Chocolate or conventional sugar-sweetened dark chocolate bar on two occasions in a randomized crossover trial. Blood glucose levels will be measured by finger prick for 120 minutes after consumption to determine postprandial glucose excursions after consumption of each type of chocolate bar.

Due to the COVID-19 pandemic, the trial was converted to be completed remotely/virtually with participants completing the testing at their home under the supervision of a research team member who will describe the study procedures and monitor testing via video conferencing.

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Kelowna, British Columbia, Canada, V1V 3G1
      • University of British Columbia Okanagan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• physician-diagnosed T1D or T2D of ≥1 year;
• current HbA1c of 6.5-8.5%;
• BMI: 25-40 kg/m2;
• blood pressure of <160/99 mm Hg assessed according to guidelines;
• non-smoking;
• not on hormone replacement therapy, corticosteroids, or anti-inflammatory medications;
• 18-75 years old.

Exclusion Criteria:

• Are taking more than 2 glucose lowering medications;
• Are ongoing medical treatment for diseases such as cancer, auto-immune or inflammatory disease, liver or kidney disorders;
• Have allergy, intolerance or aversion to cocoa, stevia, erythritol, inulin, or any other dietary restrictions (e.g., vegan) that will prevent them from following the standardized study diets;
• Are unable to follow remote guidance by internet or smartphone;
• Are unable to follow the controlled diet instructions;
• Are unable to read or communicate in English.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Conventional Dark Chocolate then Ross Dark Chocolate; A Conventional dark chocolate bar will be consumed and after a 1-week washout period, Ross Dark chocolate will be consumed.	Dietary supplement: Dark chocolate; Dark chocolate
Experimental: Ross Dark Chocolate and then Conventional chocolate; A dark chocolate bar sweetened with stevia, erythritol, and inulin - Ross Dark Chocolate will be consumed and after a 1-week washout period, Conventional Dark chocolate will be consumed.	Dietary supplement: Dark chocolate; Dark chocolate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood Glucose Incremental Area Under the Curve	A self-monitoring blood glucose device (OneTouch Verio IQ® kit Blood glucose monitoring system) will be used to measure blood glucose levels before and after consumption of chocolates. Incremental area under the curve will calculate the glucose above baseline fasting values across 120 minutes.	0 and 120 min after consumption of chocolate bar

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak Blood Glucose Concentration	Highest blood glucose value measured after consumption of the chocolate bar	0 and 120 minutes after consumption of chocolate bar
Peak Blood Glucose Concentration Above Baseline	Highest blood glucose value above fasting baseline after consumption of the chocolate bar	Throughout study completion: 0-120 minutes after consumption of chocolate bar
Blood Glucose	A self-monitoring blood glucose device (OneTouch Verio IQ® kit Blood glucose monitoring system) will be used to measure blood glucose levels before and after consumption of chocolates. Total area under the curve will calculate the glucose above zero across 120 minutes.	0 and 120 minutes

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Taste Questionnaire - 0 to 100 Point Scale	Self-reported taste of chocolate bars will be assessed by questionnaire with ratings from awful (0), average (50) to fantastic (100).	Throughout study completion:120 min after consumption of chocolate bar

Collaborators and Investigators

• Sponsor: University of British Columbia

Study record dates

Study Major Dates

• Study Start (Actual): November 20, 2020
• Primary Completion (Actual): May 4, 2021
• Study Completion (Actual): May 4, 2021

Study Registration Dates

• First Submitted: January 5, 2021
• First Submitted That Met QC Criteria: April 12, 2021
• First Posted (Actual): April 19, 2021

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 24, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus
• Other Study ID Numbers: H20-02122

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No