Glutathione-rich Foods for Type 2 Diabetes (GSH)

Effects of the "Glutathione Support for Health (GSH)" Plan on Glutathione Status in Type 2 Diabetes

The purpose of this research study is to find out whether certain plant-based foods may be beneficial for individuals with type 2 diabetes. To meet the goal, study participants will be fed known amounts of foods and nutrients. Before and after participants have eaten the food, they will self-measure height, weight, and waist circumference and study staff will administer questionnaires. Blood samples will be taken at a local lab to measure blood sugar and blood lipids.All study appointments will be conducted online.

Study Overview

• Status: Completed
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Other: GSH Foods; Other: Nutrition education about glutathione sources in the diet; Other: Standard of care nutrition education for type 2 diabetes

Detailed Description

This research study is a randomized, controlled trial that will evaluate whether diet and nutrition education on, and short-term partial feeding of, specific plant foods high in the antioxidant glutathione will impact total glutathione status, gamma-glutamyltransferase (GGT) activity, glucose control or insulin sensitivity in people with type 2 diabetes. Dietary education will include information on plant sources of glutathione, as well as, cooking methods to reduce glycation and lipid peroxidation during cooking, which may indirectly alter glutathione status by reduce demand for elimination of these compounds. Participants will be randomized to one of two groups: the educational intervention plus partial feeding of two small meals per day vs. a wait list control group that will receive standard advice on nutrition for diabetes. After 12 weeks, the intervention group will no longer receive foods, but will be followed for 12 additional weeks to determine if lasting effects are achieved. After 12 weeks, the control group will receive access to the educational materials, but will not receive study foods, to see if the educational intervention alone impacts food/nutrition choices. Both groups will have lab measures (as described above) again after this additional 12 weeks, for a total duration of 24 weeks in the trial.

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Diego, California, United States, 92093
      • University of California, San Diego

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Men and women
• Ages 18 to 65
• Type 2 diabetes
• Free of self-reported acute and confounding chronic diseases (e.g., heart failure, kidney disease, liver disease, gastrointestinal disorder) based on a standardized medical history questionnaire
• Free of alcoholism, smoking and major cardiovascular event with the past 6 months
• Not on insulin to help manage diabetes
• Planning on staying in the San Diego area for the next 6 months
• Willing to select plant-based foods from a "menu" and eat the selected foods provided by the study team
• Have access to the internet and a computer
• Willing to view 4 weekly educational classes online, followed by periodic telephone and email contacts
• Agree to schedule and complete periodic questionnaires and measurements during up to four total online appointments

Exclusion Criteria:

• Alcoholism, smoking and recent cardiovascular events
• Individuals will be excluded if they report any dietary restrictions, allergies or preferences
• Unsuitability based on screening visit

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm 1: Experimental Feeding; Small glutathione-rich meals will be prepared and delivered to participants for 12 weeks.	Other: GSH Foods; The intervention consists of customized foods/small meals that have been designed to be high in a single nutrient called glutathione (GSH).; Other: Nutrition education about glutathione sources in the diet; Four videos will outline food sources of glutathione, cooking methods to reduce systemic requirements for glutathione, food sources of nutrient cofactors for glutathione production and other related content.
Active Comparator: Arm 2: Education Control; Standard of care medical nutrition education for type 2 diabetes will be provided in the form of electronic handouts and web-based resources.	Other: Standard of care nutrition education for type 2 diabetes; The educational control is provided with information on standard dietary interventions for diabetes as electronic handouts and web links.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total glutathione	Total glutathione concentration in the blood	12 weeks
gamma-glutamyltransferase (GGT)	Measure of glutathione demand in the blood	12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fasting glucose	Serum glucose concentration while fasting	12 weeks
Fasting insulin	Plasma insulin concentration while fasting	12 weeks
Hemoglobin A1c	Measure of glycemic control	12 weeks
Homeostasis Assessment Index of Insulin Resistance (HOMA-IR)	Estimate of insulin resistance	12 weeks
Low density lipoprotein concentration (LDL-c)	concentration of LDL lipoproteins in serum	12 weeks
High density lipoprotein concentration (HDL)	concentration of HDL lipoproteins in serum	12 weeks
Triglycerides	concentration of triglycerides in serum	12 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total glutathione	Total glutathione concentration in the blood	24 weeks
gamma-glutamyltransferase (GGT)	Measure of glutathione demand in the blood	24 weeks
Fasting insulin	Plasma insulin concentration while fasting	24 weeks
Fasting glucose	Serum glucose concentration while fasting	24 weeks
Hemoglobin A1c	Measure of glycemic control	24 weeks
Homeostasis Assessment Index of Insulin Resistance (HOMA-IR)	Estimate of insulin resistance	24 weeks
Low density lipoprotein concentration (LDL-c)	concentration of LDL lipoproteins in serum	24 weeks
High density lipoprotein concentration (HDL)	concentration of HDL lipoproteins in serum	24 weeks
Triglycerides	concentration of triglycerides in serum	24 weeks

Collaborators and Investigators

• Sponsor: University of California, San Diego
• Investigators: Principal Investigator: Ryan Bradley, ND, MPH, University of California, San Diego

Study record dates

Study Major Dates

• Study Start (Actual): July 28, 2020
• Primary Completion (Actual): April 2, 2021
• Study Completion (Actual): April 2, 2021

Study Registration Dates

• First Submitted: February 27, 2020
• First Submitted That Met QC Criteria: May 8, 2020
• First Posted (Actual): May 13, 2020

Study Record Updates

• Last Update Posted (Actual): January 21, 2022
• Last Update Submitted That Met QC Criteria: January 20, 2022
• Last Verified: January 1, 2022

More Information

Terms related to this study

• Keywords: Type 2 diabetes; Nutrition; Glutathione
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 180215

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