The Effect of Long-term Momordica Charantia Supplementation on Blood Glucose Levels

Study Overview
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Brief Summary
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The study is a parallel, double blind, controlled trial in which study participants will receive a 12-week intervention with 3.6 g/d dried bitter-gourd supplements or a reference intervention with 3.6 g/d dried cucumber supplements. Research subjects will come to the research facility for a test day on four occasions, with an interval of 4 weeks. The main study parameter is fasting levels of plasma glucose.

Detailed Description
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Bitter gourd (BG) (Momordica charantia) is a highly nutritive vegetable from the cucumber family. The objective is to assess the impact of 12-weeks of BG supplementation on blood glucose levels in subjects with impaired fasting glucose levels. In a previous trial (Bitter-Zoet NL70259.081.19) the short-term effects of BG (4 weeks) were studied, but no effect was observed. In the current trial a different BG cultivar is chosen, the intervention period is prolonged, the dosage per day is higher and study subjects with slightly higher fasting blood glucose levels will be included. The study is a parallel, double blind, controlled trial in which study participants will receive a 12-week intervention with 3.6 g/d dried bitter-gourd supplements or a reference intervention with 3.6 g/d dried cucumber supplements. Research subjects will come to the research facility for a test day on four occasions, with an interval of 4 weeks. The main study parameter is fasting levels of plasma glucose. Secondary outcome measures are glucose tolerance, HbA1c, insulin and HOMA-IR and HOMA-B levels.

Official Title
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The Effect of Long-term Momordica Charantia Supplementation on Blood Glucose Levels

Conditions
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Glucose, High Blood, Impaired Glucose Tolerance

Intervention / Treatment
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* Other: Bitter-gourd
* Other: Cucumber


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 40-75yrs BMI >25 kg/m2 Having a fasting glucose >6.1 mmol/L Exclusion Criteria: Use of medication/supplements that may influence the study results, such as metformin, gliclazide, glimepiride, tolbutamide, insulin, sitagliptin (DPP4 inhibitor), liraglutide (GLP-1 agonist), acarbose, repaglinide, pioglitazone, corticosteroids (systemically) , SGLT-2 inhibitors, (judged by our research physician) Having a fasting glucose >11.0 mmol/L History of gastro-intestinal surgery or having (serious) gastro-intestinal complaints History of liver dysfunction (cirrhosis, hepatitis) or liver surgery Reported slimming, medically prescribed or other extreme diets Reported weight loss or weight gain of > 5 kg in the month prior to pre-study screening Not willing to give up blood donation during the study Current smokers Alcohol intake ≥14 glasses (women) or >21 glasses (men) of alcoholic beverages per week, on average pregnant or lactating (self-reported) Abuse of illicit drugs (soft- and hard drugs) Food allergies for products that we use in the study Participation in another clinical trial at the same time Being an employee of the Food, Health & Consumer Research group of Wageningen Food & Biobased Research or dept. human nutrition and health of Wageningen University.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Bitter-gourd<br>dried bitter-gourd supplements | Other: Bitter-gourd<br>* 12-week intervention of 3.6 grams of dried bitter-gourd supplements<br>|
| Active Comparator: Cucumber<br>dried cucumber supplements | Other: Cucumber<br>* 12-week intervention of 3.6 grams of cucumber supplements<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in fasting plasma glucose concentrations | marker for glucose metabolism | Baseline (before supplementation (T0)), after 4 weeks (T2), 8 weeks (T3) and 12 weeks (T4) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in 2hour plasma glucose concentrations after a 75-gram OGTT | marker for glucose metabolism | Baseline (before supplementation (T0)) and after 12 weeks (T4) | 
| change in HbA1c | marker for glucose metabolism | Baseline (before supplementation (T0)), after 4 weeks (T2), 8 weeks (T3) and 12 weeks (T4) | 
| change in insulin | marker for glucose metabolism | Baseline (before supplementation (T0)), after 4 weeks (T2), 8 weeks (T3) and 12 weeks (T4) | 
| change in HOMA-IR levels | marker for glucose metabolism | Baseline (before supplementation (T0)), after 4 weeks (T2), 8 weeks (T3) and 12 weeks (T4) | 
| change in HOMA-B levels | marker for glucose metabolism | Baseline (before supplementation (T0)), after 4 weeks (T2), 8 weeks (T3) and 12 weeks (T4) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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bitter gourd, pre-diabetes, fasting blood glucose