Isomaltulose-Based Stimulant Beverages Can Improve Postprandial Metabolic Responses Without Compromising Cognitive Benefits Associated with Caffeinated Energy Drinks

Purpose: We hypothesised that cognition following consumption of an isomaltulose beverage would be comparable to that of an isoenergetic sucrose-based beverage, but the latter would attenuate post-ingestive metabolic responses. Methods: Thirty adults (15 males, 15 females) aged 21–44 years completed three experimental sessions, following at least 3 h fasting. Plasma insulin and glucose were measured in arterialised capillary blood 30 min after beverage consumption. Cognitive functions were assessed 45 min after beverage consumption using a computerised test battery; the primary cognitive performance outcome was a composite neurocognitive index score. Subjective symptoms were measured using questionnaires. Data are presented as the mean 95% confidence interval. Results: Circulating glucose was greater after ingesting sucrose compared to isomaltulose and placebo beverages (sucrose: 7.3 6.9, 7.7 mmol·L−1; isomaltulose: 6.3 6.1, 6.6 mmol·L−1; and placebo: 5.3 5.2, 5.4 mmol·L−1). Insulin rose to a greater degree with sucrose compared to isomaltulose (mean difference = 8.5 2.4, 14.6 µU·mL−1, p = 0.005). Non-inferiority was shown between isomaltulose and sucrose for the composite neurocognitive index score (isomaltulose mean score = 0.931 −2.3, 4.2; sucrose mean score = 0.414 −2.6, 3.5). However, performance with the sucrose and placebo beverages was similar, limiting broader interpretation. The sensation of postprandial tiredness for isomaltulose was non-inferior to sucrose (isomaltulose mean score = −3.8 −15.8, 8.2; sucrose mean score = 0.1 −10.9, 11.1). Conclusions: A commercial stimulant beverage with isomaltulose as the energy substrate elicits substantial reductions in glycaemic and insulinaemic responses compared with an isoenergetic sucrose-based beverage, without compromising cognitive performance.