Consuming raisins three times per day may reduce postprandial (post-meal) sugar levels significantly, according to a new study.

The research, conducted by Harold Bays, MD, medical director and president of Louisville Metabolic and Atherosclerosis Center (L-MARC), was presented at the American Diabetes Association’s 72nd Annual Scientific Session.

The study involved 46 adults who had slight increases in glucose levels, but no previous diagnosis of diabetes mellitus. The researchers randomly assigned participants to two groups. The first group was told to snack on raisins three times per day for 12 weeks, while the second group snacked on pre-packaged commercial snacks that did not contain raisins or other fruits or vegetables.

The researchers found that raisins considerably reduced mean post-meal glucose levels by 16% and reduced mean hemoglobin A1c by 0.12% from baseline. Pre-packaged commercial snacks on the other hand, did not significantly reduce mean post-meal glucose or hemoglobin A1c.

Dr. Bays explained:

“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 mg/dl.

This favorable glucose effect of raisins was further supported by the statistically significant reduction in hemoglobin A1c (a standard test for overall blood sugar control in diabetes mellitus) in the within group comparison to baseline. The within group comparisons from baseline with snacks did not demonstrate a reduction in hemoglobin A1c.”

James Painter, Ph.D., R.D., and nutrition research advisor for the California Raisin Marketing Board, said:

“Raisins have a relatively low glycemic index and contain fiber and antioxidants, all factors which contribute to blood sugar control. Decreasing blood sugar and maintaining normal hemoglobin A1c levels is important because it can prevent long-term damage to the heart and circulatory system.”

The research received support from the California Raisin Marketing Board through a grant to the L-MARC Research Center in Louisville, Kentucky.

Written by Grace Rattue