Effects on cognitive performance of modulating the postprandial blood glucose profile at breakfast.
OBJECTIVE
Considering the importance of glucose as a brain substrate, the postprandial rate of glucose delivery to the blood could be expected to affect cognitive functions. The purpose was to evaluate to what extent the rate of glucose absorption affected measures of cognitive performance in the postprandial period. In addition, cognitive performance was evaluated in relation to individual glucoregulation.


METHODS
A white wheat bread (WWB) enriched with guar gum (G-WWB) with the capacity to produce a low but sustained blood glucose net increment was developed. The G-WWB was evaluated in the postprandial period after breakfast with respect to effects on cognitive function (working memory and selective attention (SA)) in 40 healthy adults (49-71 years, body mass index 20-29 kg/m(2)), using a high glycaemic index WWB for comparison in a randomised crossover design.


RESULTS
The G-WWB improved outcome in the cognitive tests (SA test) in the later postprandial period (75-225 min) in comparison with the WWB (P<0.01). Subjects with better glucoregulation performed superior in cognitive tests compared with subjects with worse glucoregulation (P<0.05).


CONCLUSIONS
Beneficial effects on cognitive performance were observed with the G-WWB in the late postprandial period. The positive effect is suggested to emanate from improved insulin sensitivity, possibly in a combination with an enhanced neural energy supply. The results highlight the importance of carbohydrate foods that induces a low but sustained blood glucose profile in enhancing postprandial cognitive functions.
Division of Applied Nutrition and Food Chemistry, Department of Food Technology, Engineering and Nutrition, Lund University, Lund, Sweden. Anne.Nilsson@appliednutrition.lth.se
A
A
Nilsson
K
K
Radeborg
I
I
Björck
D000327:Adsorption; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D062408:Breakfast; D003071:Cognition / Q000502:physiology*; D018592:Cross-Over Studies; D005260:Female; D005527:Food, Fortified; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism* / Q000493:pharmacokinetics; D038321:Glycemic Index; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period / Q000502:physiology*
D001786:Blood Glucose; D005947:Glucose