Preliminary evidence that glucose ingestion facilitates prospective memory performance

Previous research has found that the ingestion of glucose boosts task performance in the memorydomain (including tasks tapping episodic, semantic, and working memory). The present pilot studytested the hypothesis that glucose ingestion would enhance performance on a test of prospectivememory. In a between-subjects design, 56 adults ranging from 17 to 80 years of age performed acomputerized prospective memory task and an attention (filler) task after 25 g of glucose or asweetness-matched placebo. Blood glucose measurements were also taken to assess the impact ofindividual differences on glucose regulation. After the drink containing glucose, cognitivefacilitation was observed on the prospective memory task after excluding subjects with impairedfasting glucose level. Specifically, subjects receiving glucose were 19% more accurate than subjectsreceiving a placebo, a trend that was marginally nonsignificant, F1,41 = 3.4, P = .07, but that had amedium effect size, d = 0.58. Subjects receiving glucose were also significantly faster on theprospective memory task, F1,35 = 4.8, P b .05, d = 0.6. In addition, elevated baseline blood glucose(indicative of poor glucose regulation) was associated with slower prospective memory responding,F1, 35 = 4.4, P b .05, d = 0.57. These data add to the growing body of evidence suggesting that bothmemory and executive functioning can benefit from the increased provision of glucose to the brain