Effects of Blood Glucose Levels on Resting-State EEG and Attention in Healthy Volunteers

Purpose:Although glucose is the primary source of energy for the human brain, only a few studies have quantitatively evaluated the effects of glucose supply in healthy fasting subjects. Thus, this study used an EEG power spectral analysis to investigate whether alterations in EEG are associated with changes in blood glucose levels in healthy fasting subjects.Methods:This study included 24 healthy volunteers who underwent resting-state EEG and completed two attention examinations following a fasting period of at least 8 hours. The same tests were repeated after the participants ingested a glucose-rich drink.Results:After consumption of the glucose-rich drink, significant increases in low alpha (8-10 Hz) and theta (4-8 Hz) power were observed in the whole brain and were especially prominent in the frontal and parieto-occipital regions. The participants performed better on the attention tests after than before the intake of glucose, but regional EEG changes were not correlated with this attentional enhancement.Conclusions:The present study demonstrated that recovery from low levels of blood glucose following a prolonged fasting period was associated with increased power in the theta and low alpha bands on a resting-state EEG and that this recovery was accompanied by improved attentional performance.