Effects of differences in postprandial glycaemia on cognitive functions in healthy middle-aged subjects

Eur J Clin Nutr. 2009 Jan;63(1):113-20. doi: 10.1038/sj.ejcn.1602900. Epub 2007 Sep 12.


Objective: To find useful methods for the studies of cognitive function during a postprandial period, and to use these methods to evaluate function after test meals differing in post meal glycaemia.

Subjects/methods: Forty healthy volunteers aged 49-70 years were studied. A glucose solution (glucose 50 g) was provided through either a bolus or sipping regimen at breakfast to simulate a high-GI or a low-GI breakfast, respectively. Cognitive tests of working memory (WM) were performed at 35, 90, 120 and 150 min after commencing the breakfast, and a test of selective attention (SA) was performed at 170 min.

Results: Subjects with higher glucose tolerance performed better in the cognitive tests (P<0.05). After entering glucose tolerance as covariate, the subjects performed better in the working memory test at 90 min (P<0.034) and in the selective attention test at 170 min (P<0.017) after the simulated low-glycaemic index (GI) breakfast compared with the simulated high-GI breakfast.

Conclusion: Possibly, the cognitive functions tested were enhanced by avoiding a sharp decline in blood glucose concentration and by maintaining a higher glycaemia in the late postprandial period, respectively. A low-GI diet is preferable in the prevention of the risk of cognitive decline as a result of less efficient glucose regulation.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Attention / drug effects*
  • Blood Glucose / metabolism*
  • Cognition / drug effects*
  • Female
  • Glucose / pharmacology*
  • Glucose Tolerance Test
  • Glycemic Index / physiology
  • Humans
  • Male
  • Memory / drug effects*
  • Middle Aged
  • Postprandial Period / physiology


  • Blood Glucose
  • Glucose