Effects of full-fat dairy products on subclinical vascular function in adults with elevated blood pressure: a randomized clinical trial

Background High consumption of low- and non-fat dairy products improves vascular dysfunction associated with elevated arterial blood pressure (BP). Currently, it is unknown if conventional full-fat dairy products improve vascular functions. Objectives To determine if adding whole milk and full-fat dairy products to the normal routine diet improves vascular function in adults with elevated BP. Design Sixty adults (age +/- SEM; 58 +/- 2 years) with elevated BP (systolic/diastolic; 120-159/ < 99 mmHg) were randomized into a controlled crossover intervention trial consisting of two 4-week dietary periods. The high dairy condition consisted of adding four daily servings of whole milk or full-fat dairy products to the normal diet and eliminated all dairy intake during the control (no dairy) condition. A 2-week washout period separated the dietary conditions. Results Carotid-femoral pulse wave velocity (cfPWV) did not differ significantly between high dairy (11.3 +/- 0.3 versus 10.9 +/- 0.3 m/sec) and no dairy conditions (11.2 +/- 0.3 versus 11.0 +/- 0.3 m/sec). The results were consistent when ultrasound-derived vascular distension measures (arterial compliance, beta-stiffness index, and elastic modulus) were evaluated. Cardiovagal baroreceptor sensitivity (via Valsalva maneuver) demonstrated no significant difference for either dietary condition. Brachial arterial flow-mediated dilation (FMD) did not differ significantly during the high dairy (5.7 +/- 0.5 versus 5.4 +/- 0.6%) and no dairy conditions (6.5 +/- 0.5 versus 5.6 +/- 0.6%). Conclusions The solitary addition of whole milk and full-fat dairy products has no effect on subclinical vascular function in adults with elevated BP.