Cardiovascular Disease
Conditions
Keywords
Fruit, Vegetables, Intervention, Insulin resistance, Cardiovascular disease risk, Dose response, High risk of cardiovascular disease
Brief summary
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.
Interventions
OTHERFruit and vegetable intervention
Dose-response effect of fruit and vegetable intake (1-2 vs 4 vs 7 portions per day for 12 weeks)
Sponsors
Queen's University, Belfast
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Insulin resistance (two-step euglycaemic-hyperinsulinaemic clamp) | Start and end of 12 week intervention |
Secondary
| Measure | 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 |
Countries
United Kingdom
Outcome results
None listed