Controlling blood pressure in diabetes is important for reducing cardiovascular morbidity and mortality. This study compared the effects of two healthy diets that differed in fat content on blood pressure and hemodynamics. We enrolled 30 adults with type 2 diabetes in a randomized, crossover, controlled-feeding study with isocaloric diet periods. After a 2wk run-in on a typical Western diet (36% total fat, 12% saturated fat), participants consumed a low-fat control diet (27% total fat, 7% saturated fat) and a moderate fat pistachio diet (33% total fat, 7% saturated fat) for 4wk each. While on the pistachio diet, participants consumed pistachios equivalent to 20% of daily calories (ranging from 2-5 ounces/day). At the end of each diet period, blood pressure and systemic hemodynamics were assessed at rest and during acute psychological stress (mental arithmetic and hand cold pressor). A subset of participants (n=20) also underwent 24hr ambulatory blood pressure monitoring. Treatment effects were assessed with the mixed models procedure in SAS v9.3. There was no difference between treatments in resting blood pressure or systemic hemodynamics. During acute stress, stroke volume and cardiac output were significantly lower following the control diet (66.4 ml/beat and 4.43 l/min) than the pistachio diet (68.4 ml/beat and 4.57 l/min). Total peripheral resistance was significantly lower following the pistachio diet than the control diet (1682 vs 1746 dyne-sec/cm5). Systolic blood pressure during the 24hr ambulatory monitoring was significantly lower following the pistachio diet than the control diet (113.8 vs 117.3 mmHg). Taken together with other recent studies, these results provide evidence that daily pistachio consumption can benefit blood pressure and systemic hemodynamics in adults with type 2 diabetes.
High saturated-fat and low-fibre intake: a comparative analysis of nutrient intake in individuals with and without type 2 diabetes
