Background: A glucose drink has been shown to improve memory in persons with poor glucose regulation and poor cognition. Objective: The objective of this study was to determine 1) whether an association between cognition and glucose regulation is apparent in healthy seniors and 2) the effects of dietary carbohydrates on cognition. Design: After an overnight fast, 10 men and 10 women (aged 60-82 y) consumed 50 g carbohydrate as glucose, potatoes, or barley or a placebo on 4 separate mornings. Cognitive tests were administered 15, 60, and 105 min after ingestion of the carbohydrate. Plasma glucose and serum insulin were measured. Results: In a multiple regression analysis, poor baseline (placebo) verbal declarative memory (immediate and 20-min delayed paragraph recall and word list recall) and visuomotor task performance were predicted by poor ␤ cell function, high incremental area under the glucose curve, low insulin resistance, and low body mass index. The difference in plasma glucose after food consumption [glucose > potatoes > barley > placebo (P < 0.03)] did not predict performance. Although overall performance did not differ with consumption of the different test foods, baseline score and ␤ cell function correlated with improvements in immediate and delayed paragraph recall for all 3 carbohydrates (compared with placebo); the poorer the baseline memory or ␤ cell function, the greater the improvement (correlation between ␤ cell function and improvement in delayed paragraph recall: r > Ϫ0.50, P < 0.03). Poor ␤ cell function correlated with improvement for all carbohydrates in visuomotor task performance but not on an attention task. Conclusions: Glucose regulation was associated with cognitive performance in elderly subjects with normal glucose tolerance. Dietary carbohydrates (potatoes and barley) enhanced cognition in subjects with poor memories or ␤ cell function independently of plasma glucose.Am J Clin Nutr 2000;72:825-36. KEY WORDSGlucose, carbohydrates, insulin, memory, cognition, elderly subjects, ␤ cells, insulin resistance, glucose regulation, glucose tolerance INTRODUCTIONThe proportion of North Americans with cognitive impairments is increasing as the population ages. It is important to understand environmental factors, such as nutrition, that may help prevent or reduce such deficits (1). However, research examining the role of specific macronutrients on cognitive function in adults is inconclusive (2, 3).Several lines of evidence suggest that impaired glucose regulation is associated with impaired cognition and that improved regulation leads to cognitive improvements. Elderly subjects with type 2 diabetes generally perform worse on memory tests than do age-matched control subjects (4), and nondiabetic subjects with poor glucose regulation perform worse than do those with better regulation (5-12). Moreover, diabetes-associated cognitive deficits can be enhanced by improving glucose regulation with oral hypoglycemic agents (13,14).A wide range of studies have shown that a glucose drink enhan...