Objective: Red wines and grape juices contain polyphenolics with antioxidant and antiplatelet properties that may be protective against oxidative stress leading to hypertension, insulin resistance, and type 2 diabetes (T2D). This study evaluated the effects of supplementing meals of subjects with 150 mL of muscadine grape juice (MJ), muscadine grape wine (MW), and dealcoholized muscadine grape wine (Dz-W) on glycemic indices, blood constituents, lipid profile, anthropometric, and nutrient intakes of healthy and T2D subjects over a 28-d period.
Methods: Subjects with T2D were assigned to take MJ, MW, or Dz-W. Non-diabetics consumed MJ and controls were given no test drinks. Several metabolic indicators associated with diabetic conditions were measured at baseline and repeated after 28 d.
Results: Diabetics given MW and Dz-W showed lower levels of blood glucose, insulin, and glycated hemoglobin, indicating better glycemic control. Elevated dietary vitamin C and E levels were observed in diabetics given Dz-W, indicating improved antioxidant status. Decreased red blood cell membrane saturated fatty acids and increased mono- and polyunsaturated fatty acids for subjects with T2D given MW suggested improved membrane fluidity. Lower sodium and chloride values for subjects T2D given MW suggested lower risk for developing hypertension. Improved hepatic conditions were noted by decreases in alanine aminotransferase and aspartate aminotransferase among subjects with T2D given MW, indicating better insulin sensitivity and decreased tendency toward impaired liver function.
Conclusion: Daily intake of 150 mL of MW or Dz-W with meals improved several metabolic responses among diabetics compared with diabetics given MJ.