Clinical trial NCT00874341: Effect of Fruit and Vegetables on Insulin Resistance
Official title: Dose-Response Effect of Fruit and Vegetables on Insulin Resistance in Healthy People Who Are Overweight and at High Risk of Cardiovascular Disease
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
Conditions: Cardiovascular Disease
Keywords: Fruit
Vegetables
Intervention
Insulin resistance
Cardiovascular disease risk
Dose response
High risk of cardiovascular disease
Lead sponsor: Queen's University, Belfast
Sponsor class: OTHER
First posted: 2009-04-02
Enrollment: 105
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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.


Eligibility criteria: 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

Primary outcomes:
measure: Insulin resistance (two-step euglycaemic-hyperinsulinaemic clamp)
timeFrame: Start and end of 12 week intervention
Secondary outcomes:
measure: Self-reported intake of fruit and vegetables (number of portions per day)
timeFrame: Start and end of 12 week intervention
measure: Cardiovascular risk factors
timeFrame: Start and end of 12 week intervention
measure: Biochemical markers of nutritional status
timeFrame: Start and end of 12 week intervention
Other outcomes:
Locations:
city: Belfast
country: United Kingdom
facility: Queen's University Belfast
state: Northern Ireland
city: Belfast
country: United Kingdom
facility: Royal Victoria Hospital
Study officials:
affiliation: Queens University Belfast
name: Michelle McKinley, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Wallace IR, McEvoy CT, Hunter SJ, Hamill LL, Ennis CN, Bell PM, Patterson CC, Woodside JV, Young IS, McKinley MC. Dose-response effect of fruit and vegetables on insulin resistance in people at high risk of cardiovascular disease: a randomized controlled trial. Diabetes Care. 2013 Dec;36(12):3888-96. doi: 10.2337/dc13-0718. Epub 2013 Oct 15.
citation: Wallace IR, McKinley MC, McEvoy CT, Hamill LL, Ennis CN, McGinty A, Bell PM, Patterson CC, Woodside JV, Young IS, Hunter SJ. Serum 25-hydroxyvitamin D and insulin resistance in people at high risk of cardiovascular disease: a euglycaemic hyperinsulinaemic clamp study. Clin Endocrinol (Oxf). 2016 Sep;85(3):386-92. doi: 10.1111/cen.13100. Epub 2016 Jun 13.
citation: McEvoy CT, Wallace IR, Hamill LL, Neville CE, Hunter SJ, Patterson CC, Woodside JV, Chakravarthy U, Young IS, McKinley MC. Increasing fruit and vegetable intake has no effect on retinal vessel caliber in adults at high risk of developing cardiovascular disease. Nutr Metab Cardiovasc Dis. 2016 Apr;26(4):318-25. doi: 10.1016/j.numecd.2015.10.010. Epub 2015 Nov 14.
citation: McEvoy CT, Wallace IR, Hamill LL, Hunter SJ, Neville CE, Patterson CC, Woodside JV, Young IS, McKinley MC. Increasing Fruit and Vegetable Intake Has No Dose-Response Effect on Conventional Cardiovascular Risk Factors in Overweight Adults at High Risk of Developing Cardiovascular Disease. J Nutr. 2015 Jul;145(7):1464-71. doi: 10.3945/jn.115.213090. Epub 2015 May 13.