Canola-Mediterranean Diet Study in T2DM

Sponsor

Unity Health Toronto (Other)

Overall Status

Completed

CT.gov ID

NCT02245399

Collaborator

University of Toronto (Other), Laval University (Other), University of Manitoba (Other), Canola Council of Canada (Other)

164

Enrollment

Locations

Arms

29.4

Actual Duration (Months)

54.7

Patients Per Site

1.9

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose of the study is to assess whether a Mediterranean-type weight-loss diet, enriched with canola oil, high in plant protein, and low in carbohydrates will produce blood sugar control, reduce coronary heart disease (CHD) risk factors and maximize weight loss, better than conventional higher carbohydrate diets in overweight diabetic patients.

Condition or Disease	Intervention/Treatment	Phase
Type 2 Diabetes Obesity Overweight Cardiovascular Diseases	Behavioral: A canola oil enriched mediterranean diet Behavioral: A high wheat fiber diet	N/A

Detailed Description

The investigators plan to assess the effects of increasing both canola oil and plant protein foods while reducing carbohydrate intake in the context of a Mediterranean type diet on weight loss, glycemic control and cardiovascular risk factors in type 2 diabetes.

Obesity rates in Western nations have shown a dramatic rise in the last 20 years and diabetes rates have doubled, a trend which is predicted to be repeated over the next 20 years. In Canada the predicted cost to the healthcare system in only 7 years will rise to $17 billion. Weight loss diets (such as Atkins, Eddies, South Beach and Zone) emphasizing carbohydrate restriction have become increasingly popular for the prevention and treatment of diabetes. As a result, lower carbohydrate diets are being selected by health conscious members of the general population including those with diabetes. Because such diets in effect promote a high intake of protein from animal sources, even in the presence of weight loss, serum cholesterol levels rise due to increased cholesterol and saturated fat intake; and a further rise in serum lipids is likely to occur in the long term when weight loss has ceased. On the other hand, lower carbohydrate dietary patterns that are higher in plant rather than animal fat and proteins have been associated with improved blood lipids and reduced risk of heart disease and type 2 diabetes.

The investigators have therefore planned a study in which a weight reducing low carbohydrate, Mediterranean type diet that is high in plant proteins and canola oil will be compared to a weight reducing high cereal fibre diet in a 3 month study. 150 overweight and obese participants with type 2 diabetes will be randomized to one of 2 treatments.

Study visits will be as follows: weeks -2, 0 (for randomization), 2, 4, 8, 10 and 12. Body measurements, blood pressure and blood samples will be taken at each visit except week 2. The week 2 visit will be mainly for reinforcement of dietary advice; also body weight will be measured and blood drawn for fast glucose and HbA1c. Diet records will be reviewed at all visits. 24 hour urine samples will be collected at week 0 and week 12.

On completion of the 12 week study, participants will be given the option of continuing on the same diet or trying the opposite diet for a further 12 weeks. Visits will be every 4 weeks for a total of 3 visit. Body measurements, blood pressure and blood samples will be taken during these visits as in the initial 12 week study.

Study Design

Study Type:

Interventional

Actual Enrollment :

164 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Investigator)

Primary Purpose:

Treatment

Official Title:

Canola Enriched Mediterranean Type Weight Loss Diet in Type 2 Diabetes

Actual Study Start Date :

Oct 1, 2014

Actual Primary Completion Date :

Dec 14, 2016

Actual Study Completion Date :

Mar 13, 2017

Arms and Interventions

Arm	Intervention/Treatment
Experimental: A canola oil enriched mediterranean diet Participants will be advised to consume, a low-carbohydrate diet (26-32% of calories), high in vegetable protein (28-32%) and fat (41-45%) with canola as the major component (10%). Carbohydrate sources will feature viscous fiber-containing foods (including psyllium cereal, oats and barley) and low-starch vegetables (emphasizing okra and eggplant) for the relatively limited amount of carbohydrate.	Behavioral: A canola oil enriched mediterranean diet The diet will be provided at 60% of calories estimated for stable body weight to encourage weight loss. A high protein canola oil-enriched test bread will be provided as a supplement. Other Names: A mediterranean weight-reducing diet emphasizing canola oil Eco-Atkins diet Low carbohydrate dietary portfolio
Active Comparator: A high wheat fiber diet Participant will be advised to consume a high carbohydrate diet (58% carbohydrate, 16% protein and 25% fat) emphasizing whole wheat/whole grain cereals and increased high fiber alternatives, with fruits and vegetables.	Behavioral: A high wheat fiber diet The diet will be provided at 60% of calories estimated for stable body weight to encourage weight loss. A whole wheat control bread will be provided as a supplement to participants Other Names: DASH-type diet

Arm

Intervention/Treatment

Experimental: A canola oil enriched mediterranean diet

Participants will be advised to consume, a low-carbohydrate diet (26-32% of calories), high in vegetable protein (28-32%) and fat (41-45%) with canola as the major component (10%). Carbohydrate sources will feature viscous fiber-containing foods (including psyllium cereal, oats and barley) and low-starch vegetables (emphasizing okra and eggplant) for the relatively limited amount of carbohydrate.

Behavioral: A canola oil enriched mediterranean diet

The diet will be provided at 60% of calories estimated for stable body weight to encourage weight loss. A high protein canola oil-enriched test bread will be provided as a supplement.

Other Names:

A mediterranean weight-reducing diet emphasizing canola oil

Eco-Atkins diet

Low carbohydrate dietary portfolio

Active Comparator: A high wheat fiber diet

Participant will be advised to consume a high carbohydrate diet (58% carbohydrate, 16% protein and 25% fat) emphasizing whole wheat/whole grain cereals and increased high fiber alternatives, with fruits and vegetables.

Behavioral: A high wheat fiber diet

The diet will be provided at 60% of calories estimated for stable body weight to encourage weight loss. A whole wheat control bread will be provided as a supplement to participants

Other Names:

DASH-type diet

Outcome Measures

Primary Outcome Measures

change in HbA1c [Measured at weeks -2, 0, and then at weeks 8, 10 and 12]
The baseline HbA1c will be the average HbA1c of weeks -2 and week 0. The end HbA1c will be the average HbA1c of weeks 8, 10 and 12. Change will be the difference between the end and baseline values

Secondary Outcome Measures

Change in body weight [baseline (week 0) and end (week 12)]
blood glucose [At weeks 0, 2, 4, 8, 10 and 12]
Serum lipids: total cholesterol, LDL-chol, HDL-chol and Triglycerides [At weeks 0, 4, 8, 10 and 12]
Blood pressure [At weeks 0, 4, 8, 10 and 12]
24-hour Ambulatory blood pressure profile [At weeks -1 and 12]
Measurement will be done using a non-invasive SpaceLabs 90217 Ambulatory BP monitor
diet history [At weeks 0, 2, 4, 8, 10 and 12]
7-day food records brought in at weeks 0, 2, 4, 8, 10 and 12 will be analyzed for macro and micro nutrient intakes.
C-reactive protein [At weeks 0 and 12]
Cholesterol absorption [At weeks -1 and 12]
This is an optional sub-study that will be carried out prior to the first and last weeks of the 12 week study. On day 1 (a Monday) of the week -1 and last weeks of the study after an overnight 12hr fast, blood will be drawn and participants will be asked to ingest 75mg of the stable carbon isotope [3, 4-13C] cholesterol dissolved in 5g of margarine and spread on half of an English muffin. Subsequent blood draws will be taken after an overnight 12hr fast, at 48 h (a Wednesday) and 72 h (a Thursday) after ingestion of the labeled cholesterol.
change in LDL particle size [Weeks 0 and 12]
LDL particle size at weeks 0 and 12 will be determined by assessing their electrophoretic characteristics obtained by non-denaturing polyacrylamide gradient (2-16%) gel electrophoresis of serum
urinary analyses [week 0 and week 12]
24 hr urine samples will be analyzed for creatinine, urea, C-peptide, minerals, electrolytes and other dietary biomarkers

Other Outcome Measures

Satiety [at weeks 0, 2, 4, 8, 10 and 12]
Using a 9-point bipolar semantic scale where -4 is extremely hungry, 0 is neutral and +4 is uncomfortably full, participants will rate their overall feeling of satiety for the previous week.
Taste (palatability) of the study diets, breads and other supplements given [At weeks 2, 4, 8, 10 and 12]
Using a scale of 1 (strongly dislike) to 10 (like very much), participants will rate the taste (palatability) of the study diet and supplements including study breads, vegan 'meats' and egg products.
The Medical Outcomes Study 36-Item Short Form Questionnaire (SF-36) [At weeks 0 and 12]
Survey on quality of life
Genetic whole genome testing [Week 0 or any other time point]
One time sample collection of buffy coat (from white cells) for future study on gene, diet and chronic disease relationship.
complete blood count (CBC) [Week 0 and week 12]
Health check at start and end of study
Renal function test [week 0 and week 12]
Health check at start and end of study
Liver function test [week 0 and week 12]
Health check at start and end of study
Prostatic specific antigen (PSA) [week 0 and week 12]
Male participants will undergo this test.
sustainability of diet [week 10 and week 12]
using a scale of 1 (study diet will be very difficult to sustain) to 10 (study diet will be very easy to sustain) participants will assess how sustainable their assigned diet will be on a long-term basis.
Testosterone level [week 0 and week 12]
Male participants will undergo this test
Estradiol level [week 0 and week 12]
Female participants will undergo this test

Eligibility Criteria

Criteria

Ages Eligible for Study:

21 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Men and women with type 2 diabetes diagnosed for more than 6 months
BMI >27 (non-Asians); BMI >25 (Asians)
HbA1c between 6.5% and 8.5% at screening, and at the preparation visit before starting diet
on a stable prescribed dose of oral diabetes medication for at least 2 months
on a stable dose of lipid medication for at least 2 weeks, if prescribed
on a stable dose of blood pressure medication for at least 1 week, if prescribed
have a family physician
can keep written food records, with the use of a digital scale

Exclusion Criteria:

Individuals with the following characteristics/conditions will be excluded

on insulin
on steroids
on warfarin (Coumadin)
GI disease (gastroparesis, celiac, colitis, Crohn's disease, Inflammatory Bowel Syndrome)
history of cancer, except non-melanoma skin cancer (basal cell, squamous cell)
major cardiovascular event (stroke, myocardial infarction) in past 6 months
major surgery in past 6 months
major debilitating disorder
liver disease (AST or ALT> 3x the upper limit of normal) except non-alcoholic fatty liver (NAFL) disease or non-alcoholic steatohepatitis (NASH).
hepatitis B or C
renal failure (creatinine > 150 mmol/L)
serum triglycerides >4.5mmol/L
acute or chronic infections (bacterial or viral)
chronic inflammatory diseases (e.g. lupus, ulcerative colitis)
blood pressure >145/90, unless approved by their family physician
alcohol consumption >2 drinks/d
food allergies to wheat, canola, or other study food components
any condition determined by the investigators to make the subject unsuitable for the study

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba	Winnipeg	Manitoba	Canada	R3T 6C5
2	Risk Factor Modification Centre, St. Michael's Hospital	Toronto	Ontario	Canada	M5C 2T2
3	Institute of Nutraceuticals and Functional Foods, Laval University	Quebec City	Quebec	Canada	G1V 4G2

Sponsors and Collaborators

Unity Health Toronto
University of Toronto
Laval University
University of Manitoba
Canola Council of Canada

Investigators

Principal Investigator: David J Jenkins, MD, St. Michael's Hospital / University of Toronto
Study Director: Cyril Kendall, PhD, University of Toronto
Study Director: Vladimir Vuksan, PhD, Unity Health Toronto
Study Director: Peter Jones, PhD, University of Manitoba
Study Director: Benoit Lamarche, PhD, Laval University