Amelioration of Cardiometabolic Risk Factors With a Pecan‐rich Diet in Overweight and Obese Adults

Abstract

Evidence from in vitro and observational studies indicates tree nuts may reduce the risk of cardiovascular diseases (CVD) and type 2 diabetes mellitus (T2DM), though support from controlled feeding trials is limited. Most nut intervention studies to date have counseled subjects to incorporate nuts into their usual diet, an approach that can neither control for inter‐individual variability in the background diet, nor fully account for the intake of other food/beverage components that can influence CVD and T2DM risk, e.g., antioxidants, fatty acids, and fiber. We conducted a 12 wk randomized, controlled, cross‐over feeding trial to examine the effects of pecans in overweight and obese men and postmenopausal women ≥45 y with central adiposity. Subjects (n=25) were randomized to either a diet resembling the average American diet (control) or the same diet with whole pecans (intervention) incorporated at ~15% of energy (1.5 oz/2000 kcal) for 4 wk, and then the opposite diet for the final 4 wk. Total fat and fiber in these isocaloric diets were similar, and all meals/snacks were provided. During the 2 wk run‐in and 4 wk washout periods, subjects were counseled to consume the control diet. A multivariate multilevel model was used to simultaneously analyze change in z‐scores of insulin, glucose, total cholesterol, triglycerides, and LDL. An interim analysis (n=18) yielded a mean increase of 0.11 SD in the control arm and a decrease of 0.23 SD in the intervention arm (mean difference between arms = 0.34 SD, P=0.047). Although differences in favor of the intervention arm were observed for all individual cardiometabolic risk factors, the sample size was too small for them to reach statistical significance. Preliminary evidence suggests a pecan‐rich diet may have a benefit in modifying cardiometabolic risk factors.Support or Funding InformationSupported by USDA and the National Pecan Shellers Association