Clinical trial NCT02909803: Measuring the Glycemic Index and Tracking Metabolites of New and Emerging Lentil Varieties
Official title: Measuring the Glycemic Index and Tracking Metabolites of New and Emerging Lentil Varieties
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hyperglycemia
Dietary Modification
Keywords: glucose
glycemic index
lentil
polyphenols
metabolites
bioavailability
Lead sponsor: Guelph Food Research Centre
Sponsor class: OTHER_GOV
Collaborators: name: Glycemic Index Laboratories, Inc
name: University of Manitoba
First posted: 2016-09-21
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: It is not known whether different lentil varieties have the same efficacy in lowering blood glucose. Similarly, the carbohydrate component of lentils responsible for lowering blood glucose is not known, nor is the bioavailability of lentil metabolites and polyphenol bioactive.

Detailed description: The overall aim of this work is to produce credible evidence for substantiating a food health claim for post prandial blood glucose lowering by lentil. Although several studies have shown that lentil consumption results in a lowering of post prandial blood glucose, it is not known whether different lentil varieties have the same efficacy. Similarly, the carbohydrate component of lentils responsible for lowering blood glucose is not known, nor is the bioavailability of lentil metabolites and polyphenol bioactive. The investigators hypothesize that the slowly digestible starch content of lentil is inversely related to in vivo glycemic response. The specific aims of this study are: (i) to identify the putative component(s) in lentil that might account for its blood glucose lowering effect, and (ii) to identify differences in blood glucose reduction among lentil varieties. These aims will be achieved in a three-step process. Firstly, in vitro studies will be pursued to determine the carbohydrate fractions of 20 new and emerging Canadian lentil varieties. Secondly, these results will be used to choose 8 lentil varieties with different slowly digestible starch content for a human Glycemic Index study. Thirdly, identification of lentil metabolites will be achieved by collecting extra capillary blood (200uL)and urine samples at fasting and 120min for measurement of polyphenols and metabolites using established HPLC and metabolomics techniques.

Eligibility criteria: Inclusion Criteria:

* Male or non-pregnant females, 18-75 years of age, inclusive
* Body mass index (BMI) \< 40 kg/m²
* Willing to maintain habitual diet, physical activity pattern, and body weight throughout the trial and to refrain from smoking for 12hr prior to each visit.
* Normal fasting serum glucose (\<7.0mmol/L capillary corresponding to whole blood glucose \<6.3mmol/L).
* Understanding the study procedures and willing to provide informed consent to participate in the study and authorization to release relevant protected health information to the study investigator.

Exclusion Criteria:

* Failure to meet any one of the inclusion criteria
* Known history of AIDS, hepatitis, diabetes or a heart condition
* Subjects using medications or with any condition which might, in the opinion of Dr. Wolever, the Medical Director of GI Labs, either: 1) make participation dangerous to the subject or to others, or 2) affect the results.
* Major trauma or surgical event within 3 months of screening.
* Unwillingness or inability to comply with the experimental procedures and to follow GI Labs safety guidelines.
* Known intolerance, sensitivity or allergy to any ingredients in the study products.

Primary outcomes:
measure: Glycemic Response
timeFrame: 120 minutes after consuming each test or control food
Secondary outcomes:
measure: Lentil metabolites in blood and urine
timeFrame: Urine and additional 200uL blood samples will be collected before eating test meal and at 120 minutes after.
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Glycemic Index Laboratories, Inc
state: Ontario
Study officials:
affiliation: Guelph Research and Development Centre
name: Dan Ramdath, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Health Canada. Bureau of Nutritional Sciences, food directorate, health products and food branch. June 2013. Draft guidance document on food health claims related to the reduction in post-prandial glycaemic response
citation: Wolever TM, Jenkins DJ. The use of the glycemic index in predicting the blood glucose response to mixed meals. Am J Clin Nutr. 1986 Jan;43(1):167-72. doi: 10.1093/ajcn/43.1.167.
citation: Wolever TMS (2006). The Glycaemic Index: A Physiological Classification of Dietary Carbohydrate. CABI Publishing, Wallingford, UK.
citation: Ramdath D, Renwick S, Duncan AM. The Role of Pulses in the Dietary Management of Diabetes. Can J Diabetes. 2016 Aug;40(4):355-63. doi: 10.1016/j.jcjd.2016.05.015.
citation: Wang, L., Zahradka, P., Taylor, C. and Aliani, M., Metabolomics Analysis of Serum and Urine After Bean Consumption by Patients with Peripheral Arterial Disease. The FASEB Journal, 30(1 Supplement): 682-10, 2016.