Effect of Green Coffee Extract Combined With Alpha-Lipoic Acid on Blood Glucose Homeostasis in Healthy Adults (GCE)

Green coffee extract (GCE) supplementation has been shown to induce favourable health benefits on glucose metabolism and weight management. Previous literature suggests that the benefits of GCE are due to the high bioavailability of chlorogenic acid (CGA) which is known for its antioxidant and anti-inflammatory properties but is destroyed during the bean roasting process used to make coffee in Western societies. Whilst some studies examining chronic and high dose GCE supplementation (4-12 weeks) report beneficial effects on glucose metabolism and reductions in body mass following supplementation, comparably less is known about the effect of acute (single dose) GCE supplementation. Another natural compound, alpha-lipoic acid (ALA) has antioxidant properties and may also benefit glucose metabolism. The purpose of the current study is to determine the impact of acute supplementation of GCE with ALA on postprandial blood glucose concentration following consumption of a carbohydrate drink in healthy adults. A secondary objective is to evaluate the effect of GCE+ALA on blood insulin concentrations, insulin sensitivity, glucose oxidation, and perceptions of appetite.

Study Overview

• Status: Recruiting
• Conditions: Nutrition, Healthy
• Intervention / Treatment: Dietary supplement: GCE + Low ALA; Dietary supplement: GCE + High ALA; Dietary supplement: Placebo

Detailed Description

The primary purpose of this study is to determine if GCE combined with ALA supplementation influences postprandial glucose metabolism. Participants will complete 3 visits to the investigator's laboratory at the University of Toronto. On each occasion, participants will consume a sugary drink (75g sugar) and investigators will take blood and breath samples for 2 hours. Participants will also be asked to fill out some questionnaires about appetite during this time. Thirty minutes before consuming the sugary drink, participants will consume one of the following pill supplements in a randomized order: 1) 200mg CGE + 200mg ALA; 2) 200mg GCE + 400mg ALA; or 3) Placebo (no CGE or ALA).

The study will advance knowledge regarding the effects of GCE and ALA on postprandial glycemia and insulin sensitivity.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jenna Gillen, PhD; Phone Number: 14169783244; Email: jenna.gillen@utoronto.ca
• Study Contact Backup: Name: Mirey Karavetian, PhD; Email: mirey.karavetian@utoronto.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M4K1C8
      • Recruiting
      • Goldring Centre for High Performance Sport
      • Contact: Jenna Gillen; Phone Number: 14169783244; Email: jenna.gillen@utoronto.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18-45 years
• BMI 20 - 30 kg/m2
• Weight stable (within ± 2kg for at least 6 months)
• Experiencing monthly menstrual periods (eumenorrheic) if female
• Non-smoker

Exclusion Criteria:

• Previous history of cardiovascular or metabolic disease
• Use of medication for managing blood glucose or lipid metabolism
• Current use of monophasic or biphasic oral contraceptives within the last 3 months (triphasic oral contraceptives are okay)
• Current supplementation of green coffee extract or supplementing in the last 3 months
• Irregular menstrual cycles (<21 days or >35 days)
• Pregnant or lactating
• Recreational smoking of any form (tobacco or cannabis)
• Not willing to consume the 24-hour control diet prior to metabolic trials

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: GCE + Low ALA; Green coffee extract and a low dose of alpha-lipoic acid prior to an oral glucose tolerance test	Dietary supplement: GCE + Low ALA; Participants will consume a pill containing 200mg green coffee extract and 200mg alpha-lipoic acid 30 minutes before a 75g oral glucose tolerance test
Active Comparator: GCE + High ALA; Green coffee extract and a moderate dose of alpha-lipoic acid prior to an oral glucose tolerance test	Dietary supplement: GCE + High ALA; Participants will consume a pill containing 200mg green coffee extract and 400mg alpha-lipoic acid 30 minutes before a 75g oral glucose tolerance test
Placebo Comparator: Placebo; Inert placebo pill prior to an oral glucose tolerance test	Dietary supplement: Placebo; Participants will consume a placebo pill (500mg insoluble microcrystalline cellulose, 5mg magnesium stearate, 5mg silicon dioxide) prior to a 75g oral glucose tolerance test

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glucose incremental area under the curve	glucose incremental area under the curve measured during an oral glucose tolerance test	2 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean glucose concentration	Mean glucose concentration measured during an oral glucose tolerance test	2 hours
Insulin incremental area under the curve	insulin incremental area under the curve measured during an oral glucose tolerance test	2 hours
Mean insulin concentration	mean insulin concentration measured during an oral glucose tolerance test	2 hours
peak glucose concentration	peak glucose concentration measured during an oral glucose tolerance test	2 hours
peak insulin concentration	peak insulin concentration measured during an oral glucose tolerance test	2 hours
Postprandial glucose oxidation	Postprandial glucose oxidation measured with a metabolic tracer	2 hours
Insulin sensitivity	insulin sensitivity measured via the Matsuda Index during an oral glucose tolerance test	2 hours
Appetite perceptions	Visual analog scales (0-100) will be used to determine perceptions of hunger, satisfaction, fullness, and prospective food consumption with higher scores denoting increased perceptions.	2 hours

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Iovate Health Sciences International Inc
• Investigators: Principal Investigator: Jenna Gillen, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Actual): February 8, 2024
• Primary Completion (Estimated): July 1, 2024
• Study Completion (Estimated): July 1, 2024

Study Registration Dates

• First Submitted: November 2, 2023
• First Submitted That Met QC Criteria: November 2, 2023
• First Posted (Actual): November 8, 2023

Study Record Updates

• Last Update Posted (Actual): March 20, 2024
• Last Update Submitted That Met QC Criteria: March 19, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 44741

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