The Moderating Role of Response to a Blood Glucose Challenge in Postprandial Cognition Following Consumption of Milk, Fruit Juice, and Water (FS05-05-19)

Abstract

ObjectivesResults from recent studies indicate that milk facilitates cognition in children and college students with higher fasting glucose, particularly compared to a beverage higher in sugar (i.e., fruit juice). Although other findings suggest that low-sugar options facilitate cognition in persons with larger glycemic responses to meal or glucose challenges, studies thus far have artificially dichotomized glycemic response measures, a practice that introduces imprecision and decreases statistical power. The present investigation examined postprandial cognition following milk, apple juice, and water among adults, with response to a high-sugar beverage challenge considered as a moderator. We hypothesized that participants who showed a larger glycemic response to a high-sugar beverage (apple juice) would perform better following a low-sugar beverage (2% milk) compared to juice. MethodsForty-four healthy adults attended three morning sessions after fasting overnight. In a randomized, counterbalanced, crossover design, participants completed baseline cognitive testing (CNS Vital Signs), followed by ingestion of 8 oz of 2% milk, apple juice, or water. Postprandial cognitive testing occurred 30, 90, and 150 min post-ingestion. Plasma glucose was measured pre-consumption, as well as 30, 60, 90, 120, 150, and 180 minutes after each beverage, with glycemic response assessed as the incremental area under the curve (iAUC) for plasma glucose. Processing Speed and Executive Function domain scores were analyzed using linear mixed modeling. ResultsAfter adjusting for age and BMI, analyses showed significant Beverage*iAUC*Time interactions comparing water and milk for both Processing Speed (b = 1.11 * 10–4, P = 0.01) and Executive Function (b = 7.00 * 10–6, P = 0.03). For both composites, persons with larger glycemic responses performed better after drinking milk versus water at 30 minutes, while this pattern reversed at 150 minutes. No significant differences were observed overall between apple juice and the other beverage conditions. ConclusionsMilk consumption may acutely (∼30–60 min) facilitate cognitive performance in persons with a larger glycemic response to a high-sugar beverage challenge. However, this pattern appears to reverse as blood glucose returns toward pre-consumption values. Funding SourcesWork funded by the National Dairy Council.