Diabetes Care 2013 Dec 01;36(12)3888-3896, IR Wallace, CT McEvoy, SJ Hunter, LL Hamill, CN Ennis, PM Bell, CC Patterson, JV Woodside, IS Young, MC McKinley Research · January 06, 2014
TAKE-HOME MESSAGE
- This randomized study evaluated the dose–response relationship between fruit and vegetable intake and insulin resistance in 89 patients at high-risk for cardiovascular disease. Despite good adherence to the dietary program, no statistically significant improvement was observed for whole-body, peripheral, or hepatic insulin resistance or for adiponectin multimers.
- Although negative, the study supports increased intake of fruits and vegetables to improve nutritional status.
ABSTRACT
OBJECTIVE
The purpose of this randomized controlled trial was to investigate the dose-response effect of fruit and vegetable (F&V) intake on insulin resistance (IR) in people who are overweight and at high risk of cardiovascular disease (CVD).
RESEARCH DESIGN AND METHODS
A total of 105 participants (mean age 56 years) followed a 4-week washout diet (one to two portions of F&Vs per day). Ninety-two participants completed the washout and were randomized to receive one to two, four, or seven portions of F&Vs per day for 12 weeks. IR was assessed at the start and end of this 12-week period by the two-step euglycemic-hyperinsulinemic clamp. Compliance was monitored using a combination of 4-day food diaries and plasma biomarkers of F&V intake.
RESULTS
A total of 89 participants completed the study. Participants attained self-reported F&V intakes of 1.8, 3.8, and 7.0 portions per day (P < 0.001) per group. There was a significant linear increase in serum lutein status across the groups, indicating good compliance (P < 0.001), and body weight was maintained (P = 0.77). No significant difference was found between groups in terms of a change in measures of whole-body, peripheral, or hepatic IR or adiponectin multimers.
CONCLUSIONS
Increased consumption of F&Vs, as advocated in public-health advice, has no effect on IR in overweight individuals who are at high risk of CVD when body weight is maintained. Recent evidence from systematic reviews indicates that particular classes or types of F&Vs may have particular antidiabetic properties; hence, it is possible that benefits may only be observed in response to a more specific fruit or vegetable intervention.
Diabetes Care
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 01;36(12)3888-3896, IR Wallace, CT McEvoy, SJ Hunter, LL Hamill, CN Ennis, PM Bell, CC Patterson, JV Woodside, IS Young, MC McKinley
This abstract is available on the publisher’s site: http://dx.doi.org/10.2337/dc13-0718