A pilot study of the possible effects of early morning fasting on blood glucose levels and cognitive preformance, which may impact on work safety

Abstract

Objectives: Previous investigations have demonstrated that blood glucose might play a role in the action of some aspects of cognitive performance in adults of various age ranges. Generally these studies have used a procedure where participants were tested after administration of a glucose drink. The aims of the study, was to investigate the glucose cognitive facilitation affects under more natural conditions of breakfast consumption or early morning fasting. Method: 20 participants with a mean age of 50.4 years (± 4.22) were studied. Measures of auditory verbal learning, executive function, visual attention and motor speed were compared following overnight fasting and after breakfast consumption with presumed elevation of glyceamic conditions Results: There was a significant difference under the two conditions (overnight fasting vs., breakfast consumption) on time taken to complete the motor speed test (p< 0.0005). There was also a significant condition effect on the amount of words recalled immediately on the auditory verbal learning test (p< 0.005) and the time taken to complete a simple executive function test (p< 0.0005). There was no significant effect on delayed word call on the auditory verbal learning test, attention test or the more complex executive function test. Changes in cognitive performance were significantly correlated with levels of blood glucose. Conclusion: The results of the study support the hypothesis that during neuropsychological testing, capacities of cognitive performance were inversely affected by early morning fasting and may have an impact on work place safety.