For individuals at high risk of cardiovascular disease, increased consumption of fruits and vegetables has no impact on insulin resistance, according to a study published in the Oct. 15 issue of Diabetes Care.
Ian R. Wallace, M.B.B.Ch., from Queen’s University Belfast in the United Kingdom, and colleagues examined the dose-response effect of fruit and vegetable intake on insulin resistance in a cohort of 89 overweight individuals at high risk ofcardiovascular disease. After a four-week washout diet, participants were randomized to receive one to two, four, or seven portions of fruit and vegetables per day for 12 weeks. At the start and end of the 12-week period, insulin resistance was assessed by the two-step euglycemic-hyperinsulinemic clamp.
The researchers found that across the groups there was a significant linear increase in serum lutein status, indicative of good compliance, and body weight was maintained. There was no significant difference between the groups with respect to change in measures of whole-body, peripheral, or hepatic insulin resistance or adiponectin multimers.
“Increased consumption of fruits and vegetables, as advocated in public-health advice, has no effect on insulin resistance in overweight individuals who are athigh risk of cardiovascular disease when body weight is maintained,” the authors write.