Exploring Buckwheat's Glucose Lowering Potential

This is a single site, double-blind, randomized, controlled study designed to explore buckwheat's glucose lowering effects in healthy volunteers and volunteers with type 2 diabetes. A total of 24 volunteers consisting of 12 volunteers (healthy and diabetic) per group for both the acute and chronic phases of testing will be recruited through advertisement from the local community.

In the acute testing phase, volunteers (healthy and diabetic) will be asked to attend 4 visits one week apart for the duration of 3 hours per visit. A fasting blood sample will be collected at each visit. At each visit, all volunteers will consume in random order 1 of the following 4 products: i) crackers containing buckwheat; ii) crackers without buckwheat); iii) 50 mls of oral solution containing glucose; or iv) 50 mls of oral solution containing the sugar substitute Splenda. The crackers will contain equal amounts of available carbohydrates. Blood sampling will occur at 15, 30, 45, 60 minutes, and then every 60 minutes for the remainder of the visit. Sampling (pre and post product consumption) will measure insulin, glucose, and various incretins. Open venous access will be secured after the first sample has been obtained to minimize the number of needle pricks. Total amount of blood obtained will not exceed 30 mls per visit.

In the chronic testing phase, volunteers (healthy and diabetic) will receive the crackers containing buckwheat for consumption each day for 7 days. Prior to food consumption, a fasting blood sample will be obtained each day and a urine sample will be collected on Days 1, 3, and 7 to assess bioavailability of buckwheat compounds (concentrations in blood and urine), insulin and glucose. Sampling for a lipid profile (total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides), liver (ALT), kidney (creatinine), adipose function (adipokines), various incretins, as well as inflammatory status (various cytokines) will be done on Day 1 and Day 7. Total amount of blood obtained will not exceed 30 mls per visit.

Inclusion criteria

• aged 18 to 70 years
• normal glycated hemoglobin (<6% healthy, <7.5% diabetic)
• absence of chronic conditions (except Type 2 diabetes)
• must be able to read and sign consent
• must be able to comply with protocol requirements

Exclusion criteria

• allergies to eggs, buckwheat, rice flour, or sugar substitutes (Splenda)
• acute or chronic conditions (except Type 2 diabetes)
• blood glucose >10mmol/L at beginning of test session
• medications that affect glycemic control