The effects of blood sugar level changes on cognitive function, affective state, and somatic symptoms

Abstract

In an attempt to find out whether decreased blood sugar level is associated with impaired cognitive function, adverse emotional changes, or somatic symptoms, 35 subjects who suspected that they had hypoglycemia were given 5-hr glucose tolerance tests (GTTs). Nine blood samples were taken during the GTT, and the subject's mood, Serial Sevens Test (SST) performance, and somatic symptom reports were recorded on each occasion of sampling. The subjects reported significantly more negative affect and somatic symptoms after glucose nadir than before nadir. SST performance deteriorated at glucose nadir. These effects were more pronounced for subjects with high hypoglycemic index scores than for subjects with low index scores. The impairment in SST performance was greater for subjects who showed rapid decreases in blood sugar than for subjects who showed slow decreases. Dividing subjects by high and low nadirs did not reveal any differences in symptomatology.

Food for thought? Trust your unconscious when energy is low.

“…The brain relies on glucose for almost all of its operations (Scholey, Harper, & Kennedy, 2001;Siesjo, 1978;Taylor & Rachman, 1988). Cerebral stores of glucose and glycogen run out in a matter of minutes (Marks & Rose, 1981).…”

Cognitive and physiological effects of an ?energy drink?: an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions

“…It has been used to assess cognitive impairment during hypoglycaemia (e.g. Hale et al 1982;Taylor and Rachman 1987), and has also been used to investigate the relationship between blood glucose levels and cognitive performance Scholey 2001;Scholey et al 2001) and the acute effects of ginkgo and ginseng (Scholey and Kennedy 2002). In the current study, computerised versions of serial subtractions were implemented (see Scholey et al 2001 for details), here using tests of 2 min duration.…”

Acute cognitive effects of standardised Ginkgo biloba extract complexed with phosphatidylserine

“…It has been used to assess cognitive impairment during hypoglycaemia (e.g. Taylor and Rachman, 1987), and has also been used to investigate the relationship between increased blood glucose levels and cognitive performance (Kennedy et al, 2000;Scholey et al, 2001;Scholey, 2001). In the current studies, computerised versions of serial subtractions were implemented (see Scholey et al, 2001 for details), here using tests of 2-min duration.…”