Lead researcher Dr. Harold Bays, medical director and president of Louisville Metabolic and Atherosclerosis Center, said the study included 46 men and women who had not previously been diagnosed with type 2 diabetes, but who had mild elevations in glucose levels.
Participants were randomly assigned to snack on raisins or prepackaged commercial snacks that did not contain raisins or other fruits or vegetables, three times a day for 12 weeks, Bays said.
The study, funded by the California Raisin Marketing Board, found compared to the control snacks, raisins significantly decreased mean post-meal glucose levels by 16 percent, and they reduced mean hemoglobin A1c -- three-month average of blood sugar scores -- by 0.12 percent, while consumption of the control snacks did not significantly reduce mean post-meal glucose or hemoglobin A1c.
"Compared to the snacking control group, the group consuming raisins had a significant statistical reduction in their after-liquid meal blood sugar levels among study participants who had mean baseline fasting glucose levels between 90 and 100 milligrams per deciliter," Bays said.
The findings were presented at the American Diabetes Association's 72nd annual scientific session in Philadelphia.