This is a multi-site, double-blind, randomized, controlled food intervention study being conducted at the Canadian Centre for Agri-Food Research in Health and Medicine (CCARM) in Winnipeg and the Mayo Clinic, Rochester, MN, to examine the effects of a portfolio of functional foods on blood glucose and lipids, and blood vessel function in individuals with prediabetes.

A total of 116 participants (n=58/site) with prediabetes (hemoglobin A1c ≥6.0 & <7.0 and no glucose-lowering medications) and body-mass index (BMI) 18-40 will be recruited for a 12-week clinical trial to determine the effect of eating 2 items containing functional ingredients daily compared to 2 similar items lacking the functional ingredients. Study foods provided are to be incorporated into participant's usual diet.

This study will investigate the effect of a 12 week intervention with a portfolio of 7 food products and 7 comparator products for their effect on glycated hemoglobin, blood lipids, blood vessel function and metabolic parameters in persons with prediabetes. Prediabetes precedes the manifestation of type 2 diabetes and is therefore an appropriate target for dietary interventions. It is also associated with increased cardiovascular disease (CVD) risk because of the presence of abdominal obesity, elevated LDL-cholesterol and reduced vascular function. CVD risk will be assessed based on the profile of lipids and other factors in the blood as well using specialized equipment for non-invasive monitoring of blood vessel function.

If the foods prove beneficial for managing blood glucose levels, the publication of results in scientific journals and in lay documents will increase awareness and provide important information of the health benefits of these products for consumers, health professionals and the food industry. It will also help individuals who may be able to manage their illnesses in a healthful non-pharmaceutical nutritional approach and who may benefit from physician-prescribed nutritional counseling with a focus on foods known to improve certain disease biomarkers. At this time these approaches lack practicality and direct application to individuals who are interested in adopting a new dietary regime capable of disease prevention.

Inclusion Criteria:

Participants must meet the following criteria to be eligible for participation in the study:

1. Male, or non-pregnant, non-lactating females, aged 21 - 75 years;
2. Glycated hemoglobin A1c ≥6.0% and <7.0%;
3. Body-mass index 18-40;
4. Able to read, write and communicate orally in English;
5. Willing to maintain a stable level of activity during participation in the study;
6. Willing to comply with protocol requirements and procedures;
7. Willing to provide written informed consent.

Exclusion Criteria:

Failure to meet any one of the above eligibility criteria will result in an inability to participate in the study. Participants will also be excluded if they have or require any of the following:

1 Previous diagnosis of diabetes or taking diabetes medications (glucose-lowering medications, insulin);

2. Previous diagnosis of cardiovascular disease (e.g. heart attack, stroke, peripheral artery disease), or taking lipid-lowering medications, or having a surgical procedure/intervention to treat cardiovascular disease (e.g. bypass surgery, stent). [Note that individuals with hypertension and/or taking anti-hypertensive medication are eligible to participate.];

3. Fasting LDL-cholesterol >160 mg/dL (>4.1 mmol/L);

4. Fasting triglycerides >400 mg/dL (>4.5 mmol/L);

5. Serum alanine aminotransferase (ALT) outside the normal range of 7-56 units/L;

6. Serum creatinine outside the normal range of 0.7-1.3 mg/dL for males and 0.6-1.1 mg/dL for females;

7. Conditions which affect normal nutrient absorption (e.g. Celiac disease, inflammatory bowel disease);

8. Untreated endocrine disorders with the potential to affect glucose and lipid metabolism;

9. In the previous 3 months and during the study, consumption of supplements or herbals in amounts that lower blood glucose or blood lipids (e.g. chromium, margarine with plant sterols, high fibre supplements such as Metamucil, cinnamon extract, ginseng, bitter melon, gamma-linolenic acid);

10. Food allergies or intolerances which severely limit the variety of study food products that can be consumed;

11. Eating philosophies or eating patterns that would limit or not include consumption of the study foods;

12. Any acute medical condition or surgical intervention within the past 3 months;

13. Conditions or medications which are likely to increase the risk to the participants or study personnel, or to reduce the ability of the participant to comply with the protocol, or affect the results;

14. Currently participating in or having participated in a food intervention study within the last month;

15. Inability to adhere to the study protocol;

16. Unable to obtain blood sample at the screening and/or baseline visit.