Berry Components and Blood Sugar & Fat Metabolism

Study Overview
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Brief Summary
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The primary objective of this study is to determine which components of berries improve glucose metabolism and increase fat oxidation in humans.

Detailed Description
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The aim of this study is to improve understanding of how diet can regulate glucose metabolism and fuel use. Previous human and animal studies have demonstrated that berries can improve gluco-regulation and increase fat oxidation. The aim of this study is to determine which component of berries is conveying this health benefit.

Official Title
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Berry Components and Blood Sugar & Fat Metabolism

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Other: Mixed Berry Diet
* Other: Carbohydrate Control Jello
* Other: Fiber Enriched Jello
* Other: Low Fiber Mixed Berry Juice


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy non-smoker able to understand consent Exclusion Criteria: Body Mass Index less than 25 kg/m2 pregnant, lactating, having given birth in the past year allergy to berries blood glucose greater than 125 mg/dL history of bariatric surgery or nutrient malabsorption disease diagnosis or treatment of cancer in past three years type 2 diabetes requiring the use of diabetes pills, insulin, or non-insulin shots

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Mixed Berry Diet<br>Participants will receive between 400 to 800 grams of mixed berries daily, as a proportion of their daily caloric intake added to their base diet. The base diet will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. | Other: Mixed Berry Diet<br>* Mixed Berry Treatment<br>|
| Other: Carbohydrate Control Jello<br>Participants will receive between 400 to 800 grams of strawberry jello daily, as a proportion of their daily caloric intake added to their base diet. The jello will be matched to the mixed berries in both total carbohydrate level and gram quantity. The base diet will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. | Other: Carbohydrate Control Jello<br>* Carbohydrate Control<br>|
| Other: Fiber Enriched Jello<br>Participants will receive between 400 to 800 grams of fiber enriched strawberry jello daily, as a proportion of their daily caloric intake added to their base diet. The jello will be matched to the mixed berries in both total carbohydrate level and fiber content, and in the same gram quantity. The base diet will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. | Other: Fiber Enriched Jello<br>* Fiber Control<br>|
| Other: Low Fiber Mixed Berry Juice<br>Participants will receive 1 liter per day of low fiber mixed berry juice added to their base diet. The juice will be squeezed from the mixed berries, then filtered. The sugar level of the juice will match that of the mixed berries. The base diet will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. | Other: Low Fiber Mixed Berry Juice<br>* Anthocyanin Control<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glucose Metabolism Phase 1 | Subjects will undergo a meal-based glucose tolerance test; blood samples will be analyzed for glucose in mmol/L. | Day 8 | 
| Glucose Metabolism Phase 2 | Subjects will undergo a meal-based glucose tolerance test; blood samples will be analyzed for glucose in mmol/L. | Day 29 | 
| Glucose Metabolism Phase 3 | Subjects will undergo a meal-based glucose tolerance test; blood samples will be analyzed for glucose in mmol/L. | Day 50 | 
| Glucose Metabolism Phase 4 | Subjects will undergo a meal-based glucose tolerance test; blood samples will be analyzed for glucose in mmol/L. | Day 71 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin sensitivity | Subjects will undergo a meal-based glucose tolerance test; blood samples will be analyzed for insulin in units of microIU/mL. | Day 8, 29, 50, 71 | 
| Fat trafficking | Subjects will undergo a meal-based glucose tolerance test; blood samples will be analyzed for non-esterified fatty acids in mmol/L. | Day 8, 29, 50, 71 | 
| Peripheral mononuclear blood cells energetics | Blood cells called peripheral mononuclear blood cells will be isolated and analyzed for mitochondrial function/oxygen consumption in nmol/ml. | Day 8, 29, 50, 71 | 
| Metabolic Fuel Use | Subjects will spend the night in an indirect calorimeter to measure their oxygen consumption and carbon dioxide evolution which will be used to calculate the dietary energy source being oxidized, expressed as respiratory quotient which is a unitless ratio of liters of O2 inhaled to liters of CO2 exhaled. | Day 7-8, 28-29, 49-50, 70-71 |