Technical Abstract: Objective Previously, four months of a blueberry-enriched (BB) antioxidant diet prevented impaired object recognition memory in aged rats. Experiment 1 determined whether one and two-month BB diets would have a similar effect and whether the benefits would disappear promptly after terminating the diets. Experiment 2 determined whether a one-month BB diet can subsequently reverse existing object memory impairment in aged rats. Methods In Experiment #1, Fischer 344 rats were maintained on an appropriate control diet or on one or two months of the BB diet prior to testing object memory at 19 months post-natal (p.n.). In Experiment #2, rats were tested for object recognition memory at 19 months and again at 20 months after a month of maintenance on a 2% blueberry-enriched or control diet. Results In Experiment 1, the control group performed no better than chance, while the one-month and two-month BB diet groups both performed similarly and significantly better than controls. The two-month BB-diet group, but not the one-month group, maintained its performance over a subsequent month on a standard laboratory diet. In Experiment 2, the 19-month old rats performed near chance. At 20 months of age, the rats subsequently maintained on the BB diet significantly increased their object memory scores , while the control diet group exhibited a non-significant decline. The change in object memory scores differed significantly between the two diet groups. Conclusions These results suggest that a considerable degree of age-related object memory decline in aged rats can be both prevented and reversed by brief maintenance on blueberry-enriched diets.