Scientific Study

OBJECTIVE: The authors tested the hypothesis that in adults with prediabetes; an almond-enriched American Diabetes Association (ADA) diet improves measures of insulin sensitivity and other cardiovascular risk factors compared with an ADA nut-free diet. METHODS: DESIGN: Randomized parallel-group trial. SETTING: Outpatient dietary counseling and blood analysis. SUBJECTS: Sixty-five adult participants with prediabetes. INTERVENTION: Sixteen weeks of dietary modification featuring an ADA diet containing 20% of energy from almonds (approximately 2 oz per day). Measures of Outcome: Outcomes included fasting glucose; insulin; total cholesterol (TC); low-density lipoprotein cholesterol (LDL-C); high-density lipoprotein cholesterol (HDL-C); triglycerides; TC:HDL-C; and HbA1c; which were measured at weeks 0; 8; and 16. Body weight; body mass index (BMI); waist circumference; blood pressure; and nutrient intake were measured at weeks 0; 4; 8; 12; and 16. RESULTS: The almond-enriched intervention group exhibited greater reductions in insulin (-1.78 µU/ml vs. +1.47 µU/ml; p = 0.002); homeostasis model analysis for insulin resistance (-0.48 vs. +0.30; p = 0.007); and homeostasis model analysis for beta-cell function (-13.2 vs. +22.3; p = 0.001) compared with the nut-free control group. Clinically significant declines in LDL-C were found in the almond-enriched intervention group (-12.4 mg/dl vs. -0.4 mg/dl) as compared with the nut-free control group. No changes were observed in BMI (-0.4 vs. -0.7 kg/m(2); p = 0.191); systolic blood pressure (-4.4 mm Hg vs. -3.5 mm Hg; p = 0.773); or for the other measured cardiovascular risk factors. CONCLUSIONS: An ADA diet consisting of 20% of calories as almonds over a 16-week period is effective in improving markers of insulin sensitivity and yields clinically significant improvements in LDL-C in adults with prediabetes.