Effect of Fruit and Vegetables on Insulin Resistance

Study Overview
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Brief Summary
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Current evidence indicates that fruit and vegetable intake and dietary patterns rich in fruit and vegetables may be associated with reduced insulin resistance and may reduce the risk of the metabolic syndrome. If proven, this relationship may partly explain the inverse association between fruit and vegetable intake and cardiovascular disease risk. There are currently no published dietary interventions that have examined in detail the relationship between fruit and vegetable intake and insulin resistance. There is, however, some preliminary evidence from whole diet interventions that a diet rich in fruit and vegetables may have a beneficial effect on insulin resistance. Evidence to date indicates that an investigation of the direct association between fruit and vegetable intakes and insulin resistance in a carefully controlled intervention study is warranted. This study will investigate the dose-response effect of fruit and vegetable intake on insulin resistance in people who are overweight and at high-risk of CVD using state-of-the-art techniques.

Official Title
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Dose-Response Effect of Fruit and Vegetables on Insulin Resistance in Healthy People Who Are Overweight and at High Risk of Cardiovascular Disease

Conditions
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Cardiovascular Disease

Intervention / Treatment
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* Other: Fruit and vegetable intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI between 27-35 CVD risk >20% over 10 years (using the Joint British Society risk assessment tables) Low consumers of fruit and vegetables (<2 portions per day) Exclusion Criteria: Diabetes Existing CVD Food intolerance/sensitivity preventing adherence to a high fruit and vegetable diet Subjects taking antioxidant supplements Surgery within the last 3 months Pregnancy/lactation Aspirin Subjects following a weight loss diet

Ages Eligible for Study
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Minimum Age: 18 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: 1<br> | |
| Active Comparator: 2<br>4 portions fruit and vegetables daily for 12 weeks | Other: Fruit and vegetable intervention<br>* Dose-response effect of fruit and vegetable intake (1-2 vs 4 vs 7 portions per day for 12 weeks)<br>|
| Active Comparator: 3<br>7 portions of fruit and vegetables daily for 12 weeks | Other: Fruit and vegetable intervention<br>* Dose-response effect of fruit and vegetable intake (1-2 vs 4 vs 7 portions per day for 12 weeks)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin resistance (two-step euglycaemic-hyperinsulinaemic clamp) |  | Start and end of 12 week intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self-reported intake of fruit and vegetables (number of portions per day) |  | Start and end of 12 week intervention | 
| Cardiovascular risk factors |  | Start and end of 12 week intervention | 
| Biochemical markers of nutritional status |  | Start and end of 12 week intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fruit, Vegetables, Intervention, Insulin resistance, Cardiovascular disease risk, Dose response, High risk of cardiovascular disease