Cardiovascular Disease, Diabetes
Conditions
Brief summary
The objective of this study is to determine the effect of reducing the rate of glucose absorption on oxidative stress after eating and to compare it with the effects of vitamin C. The hypothesis is that reducing the rate of glucose absorption will reduce oxidative stress to a similar extent as 1g vitamin C.
Detailed description
Recently, much attention has been paid to evidence that abnormalities of the postprandial state (hyperglycemia) are important contributing factors to the development of chronic disease. This attention has increased interest in the role low glycemic index (GI) foods could potentially play in preventing postprandial oxidative burst/stress. GI is a means by which to categorize carbohydrate according to their postprandial glycemic response. Low GI foods promote slow intestinal absorption, prolonged and less pronounced postprandial glycemia, may decrease risk of chronic disease, as well as provide metabolic benefit to people living with glucose abnormalities as well as those with normal glucose. Few studies have been conducted looking at the potential relationship between GI and oxidation and are limited by dietary/lifestyle confounders. The proposed study has been developed to eliminate these confounders. Hypotheses (3): 1. Sipping glucose slowly over 3h will result in less oxidative stress than ingesting the same amount of glucose as a bolus over 5min. 2. Sipping glucose will reduce oxidative stress to the same extent as 1g of oral vitamin C. 3. The effect of sipping glucose on oxidative stress will occur sooner than that of vitamin C.
Interventions
DIETARY_SUPPLEMENTglucose bolus
50g anhydrous glucose dissolved in 300ml water consumed within 10min followed by a lunch (cheese sandwich, fruit and milk) at 4h.
DIETARY_SUPPLEMENTGlucose sipping
50g anhydrous glucose dissolved in 300ml water consumed at rate of 25ml per 15min followed by a lunch (cheese sandwich, fruit and milk) at 4h.
DIETARY_SUPPLEMENTGlucose bolus plus 1g vitamin C
50g anhydrous glucose dissolved in 300ml water consumed within 10min with 1g vitamin C followed by a lunch (cheese sandwich, fruit and milk) at 4h.
DIETARY_SUPPLEMENTGlucose sipping plus 1g vitamin C
50g anhydrous glucose dissolved in 300ml water consumed at rate of 25ml per 15min. 1g vitamin C taken with first 25ml. Followed by a lunch (cheese sandwich, fruit and milk) at 4h.
Sponsors
Canadian Institutes of Health Research (CIHR)
University of Toronto
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* healthy males or females * 18 to 75 years
Exclusion criteria
* diabetes * recent hospitalization
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Incremental Area Under the Curve over 4 hours in serum TRAP (total peroxyl radical-trapping potential) | Four (4) hours after starting to eat the test meal. |
Secondary
| Measure | Time frame |
|---|---|
| Change over 6 hours from baseline in Plasma glucose | Baseline and 30, 60, 120, 180, 240, 270, 300 and 360min |
| Change over 6 hours from baseline in Plasma insulin | Baseline and 30, 60, 120, 180, 240, 270, 300 and 360min |
| Change over 6 hours from baseline in Serum vitamin C | Baseline and 2, 4 and 6h |
| Change over 6 hours from baseline in C-reactive protein | Baseline and 2, 4 and 6h |
| Change over 6 hours from baseline in Blood pressure | Baseline and 1, 2, 4, 5 and 6h |
| Change over 6 hours from baseline in Plasma free-fatty acids | Baseline and hourly for 6h |
| Change over 6 hours from baseline in Pulse pressure | Baseline and 1, 2, 4, 5 and 6h |
| Change over 6 hours from baseline in Augmentation index | Baseline and 1, 2, 4, 5 and 6h |
| Change over 6 hours from baseline in Oxidized LDL | Baseline and hourly for 6hr |
| Change from baseline in serum TRAP over 6 hours | Baseline and 30, 60, 120, 180, 240, 270, 300 and 360min |
| Change over 6 hours from baseline in Pulse | Baseline and 1, 2, 4, 5 and 6h |
Outcome results
None listed