The nature of the control of blood glucose in those with poorer glucose tolerance influences mood and cognition
The ability to control the levels of blood glucose was related to mood and cognition. 155 adults, aged 45–85 years, without a diagnosis of diabetes, were given an oral glucose tolerance test and cognitive tests. Participants were classified according to age (41–60/61–85 years), whether they had better or poorer glucose tolerance and whether blood glucose did or did not fall below baseline values. There were two main findings. Those with poorer glucose tolerance forgot more words and had slower decision times, but only if 61 years or older. Secondly as there are reports in animal studies that inducing low levels of blood glucose values benefited cognitive performance, for the first time in humans, individual differences in the tendency to develop low levels of blood glucose were considered. In those with poor glucose tolerance a tendency for blood glucose to fall below baseline values was associated with better mood and faster working memory.
KeywordsGlucose intolerance Hypoglycemia Memory Mild cognitive impairment Mood
Low blood glucose
The authors declare that they have no conflict of interest and that the work was not externally funded. We are grateful to the Swansea University for supplying the necessary facilities.
- Brun JF, Fedou C, Mercier J (2000) Postprandial reactive hypoglycaemia. Diabetes Metab (Paris) 26:337–351Google Scholar
- Convit A (2005) Links between cognitive impairment in insulin resistance: an explanatory model. Neurobiol Aging 26(Suppl. 1):31–35Google Scholar
- De Feo P, Gallai V, Mazzotta G, Crispino G, Torlone E, Perriello G, Ventura MM, Santeusanio F, Brunetti P, Bolli GB (1988) Modest decrements in plasma glucose concentration cause early impairment in cognitive function and later activation of glucose counterregulation in the absence of hypoglycemic symptoms in normal man. J Clin Investig 82:436–444PubMedCentralPubMedCrossRefGoogle Scholar
- Nelson HE (1982) National Adult Reading Test: test manual. NFER-Nelson, WindsorGoogle Scholar
- Uehara Y, Nipper V, McCall AL (1997) Chronic insulin hypoglycaemia induces GLUT-3 protein in rat brain neurons. Am J Physiol 272:716–719Google Scholar