The Effects of High and Low GI Breakfasts on Cognitive Performance in Adults With Type 2 Diabetes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01047813
Recruitment Status : Unknown
Verified July 2009 by University of Leeds.
Recruitment status was:  Recruiting
First Posted : January 13, 2010
Last Update Posted : January 13, 2010
Information provided by:
University of Leeds

Brief Summary:

Consumption of a low glycemic index (GI) diet has been shown to improve glycaemic control in type 2 diabetics(Brand−Miller et al., 2003; Jenkins et al., 2008). In addition to the benefits for glycaemic control there is some evidence for acute improvements in cognitive performance after consumption of low GI foods compared with high GI foods in both adults (Benton et al., 2003; Kaplan et al., 2000) and adolescents (Ingwersen et al., 2007; Smith and Foster, 2008).

Given these findings it is possible that low GI focused dietary interventions designed to improve glycaemic control and health outcomes for diabetic patients could also improve the cognitive function of these patients. This is of particular relevance in light of the evidence associating type 2 diabetes with cognitive decrements (Awad et al., 2004; Stewart and Loilitsa 1999; van Harten et al., 2006). To date two studies with type 2 diabetics have reported that a low GI breakfast was associated with increased verbal memory performance compared to a high GI breakfast (Greenwood et al., 2003; Papanikolaou et al. 2006). Further research should investigate the benefit of low GI foods to cognition.

The aim of this study is to examine the effects of high and low glycaemic index breakfast on cognitive performance in adults with type 2 diabetes. Participants will perform a battery of cognitive tests after consuming 3 different breakfasts (high GI, low GI, and water) on 3 different tests days. The participants will be recruited from the general public and from the Leeds Teaching Hospital diabetes clinic.

This research can benefit the development of specific dietary behaviours aimed at reducing diabetes related cognitive decline. This research is part of a PhD funded by the Economic and Social Research Council and the University of Leeds.

Condition or disease
Type 2 Diabetes

Detailed Description:
The study will conform to a randomised mixed design. Both the diabetic experimental group and the control group will take part in three conditions whereby participants will receive a high GI, a low GI, or a water breakfast delivered in a counterbalanced order. Participants will then perform the battery of cognitive tests on 2 occasions throughout the morning; 30 minutes after breakfast and 180 minutes after breakfast. Blood glucose will be measured from capillary finger-prick blood samples using diabetic glucose meters throughout the morning.

Study Type : Observational
Estimated Enrollment : 50 participants
Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: The Effects of High and Low GI Breakfasts on Cognitive Performance in Adults With Type 2 Diabetes
Study Start Date : September 2009
Estimated Primary Completion Date : March 2010
Estimated Study Completion Date : September 2010

Resource links provided by the National Library of Medicine

Type 2 diabetes
This group contains 25 participants with type 2 diabetes
control group
This group contains 25 participants withput type 2 diabetes. The control group is matched with age, education and lifestyle to the diabetes group.

Primary Outcome Measures :
  1. Cognitive performance (e.g. memory, attention, reaction time, and problem solving ability). [ Time Frame: The primary outcome is measured on three occasions during the three conditions ]
  2. Blood glucose levels [ Time Frame: These are measured during of each of the three conditions ]

Secondary Outcome Measures :
  1. Subjective sensations of appetite, mood, and mental alertness [ Time Frame: These are measured during all three conditions ]
  2. Sleep quality [ Time Frame: This is measured prior to each of the three test days and at the screening visit ]
  3. Stress levels [ Time Frame: This is measured prior to each of the three test days and at the screening visit ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Participants will be recruited from the general population using emails and posters. These will be distributed throughout the University of Leeds, Leeds Metropolitan University, and NHS sites in Leeds. GP's and diabetes specialist doctors and nurses will be asked to inform potential participants of the nature of the study. Ideally spouses, siblings or other close friends/relatives of the experimental group will be recruited for the control group in an attempt to control for education, social class and general lifestyle.

Inclusion Criteria:

  • Able to give informed consent
  • Type 2 diabetes
  • White British or White North American ethnicity and native English speakers
  • Not previously received or currently received subcutaneous insulin as part of their diabetes treatment.
  • Vision sufficiently good to complete the cognitive testing (using glasses and/or lenses).

Exclusion Criteria:

  • Dementia (as indicated using the Mini Mental State Examination <26)
  • Current (or recent i.e. in last 6 months) cigarette smoker
  • Neurological disorder
  • Previous stroke
  • Medication other than diabetes treatment medication that has a direct effect on the brain and is likely to influence cognitive function.

Co-existent diabetic complications will not be considered exclusion criteria unless they result in inability to complete the cognitive testing (e.g. insufficient vision).

These exclusion criteria have been chosen on the basis that these are factors that can affect cognitive performance. Given that the cognitive tests involve learning English words, only participants who have English as their first language can be included because different cognitive processes are used when learning in a non-native language (Wong et al., 2004). Ethnicity can influence glucose regulation and risk of diabetes. Given that part of this research is examining the relationship between glucose regulation and cognition it is important that potential confounds such as ethnicity/genetic propensity to diabetes are controlled for.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01047813

Contact: Daniel J Lamport 07792362588 ext +44
Contact: Louise Dye, Professor 01133435707 ext +44

United Kingdom
Institute of Psychological Sciences, University of Leeds, UK Recruiting
Leeds, West Yorkshire, United Kingdom, LS2 9JT
Contact: Daniel J Lamport    07792362588 ext +44   
Contact: Louise Dye, Professor    01133435753 ext +44   
Principal Investigator: Daniel J Lamport         
Sponsors and Collaborators
University of Leeds


Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Mr Daniel Lamport, Institute of Pscyhological Sciences, University of Leeds Identifier: NCT01047813     History of Changes
Other Study ID Numbers: 09/H1305/15
First Posted: January 13, 2010    Key Record Dates
Last Update Posted: January 13, 2010
Last Verified: July 2009

Keywords provided by University of Leeds:
Cognitive performance
Type 2 diabetes
Blood glucose

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases