Clinical trial NCT02245399: Canola-Mediterranean Diet Study in T2DM
Official title: Canola Enriched Mediterranean Type Weight Loss Diet in Type 2 Diabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Type 2 Diabetes
Obesity
Overweight
Cardiovascular Diseases
Keywords: Weight loss
Diabetes
Cardiovascular disease (CVD) risk
Weight loss diet
mediterranean type diet
Canola oil
Low-carbohydrate diet
Glycemic index
Lead sponsor: Unity Health Toronto
Sponsor class: OTHER
Collaborators: name: University of Toronto
name: Laval University
name: University of Manitoba
name: Canola Council of Canada
First posted: 2014-09-19
Enrollment: 164
Sex: ALL
Minimum age (years): 21
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: change in HbA1c
timeFrame: Measured at weeks -2, 0, and then at weeks 8, 10 and 12
Secondary outcomes:
measure: Change in body weight
timeFrame: baseline (week 0) and end (week 12)
measure: blood glucose
timeFrame: At weeks 0, 2, 4, 8, 10 and 12
measure: Serum lipids: total cholesterol, LDL-chol, HDL-chol and Triglycerides
timeFrame: At weeks 0, 4, 8, 10 and 12
measure: Blood pressure
timeFrame: At weeks 0, 4, 8, 10 and 12
measure: 24-hour Ambulatory blood pressure profile
timeFrame: At weeks -1 and 12
measure: diet history
timeFrame: At weeks 0, 2, 4, 8, 10 and 12
measure: C-reactive protein
timeFrame: At weeks 0 and 12
measure: Cholesterol absorption
timeFrame: At weeks -1 and 12
measure: change in LDL particle size
timeFrame: Weeks 0 and 12
measure: urinary analyses
timeFrame: week 0 and week 12
Other outcomes:
measure: Satiety
timeFrame: at weeks 0, 2, 4, 8, 10 and 12
measure: Taste (palatability) of the study diets, breads and other supplements given
timeFrame: At weeks 2, 4, 8, 10 and 12
measure: The Medical Outcomes Study 36-Item Short Form Questionnaire (SF-36)
timeFrame: At weeks 0 and 12
measure: Genetic whole genome testing
timeFrame: Week 0 or any other time point
measure: complete blood count (CBC)
timeFrame: Week 0 and week 12
measure: Renal function test
timeFrame: week 0 and week 12
measure: Liver function test
timeFrame: week 0 and week 12
measure: Prostatic specific antigen (PSA)
timeFrame: week 0 and week 12
measure: sustainability of diet
timeFrame: week 10 and week 12
measure: Testosterone level
timeFrame: week 0 and week 12
measure: Estradiol level
timeFrame: week 0 and week 12
Locations:
city: Winnipeg
country: Canada
facility: Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba
state: Manitoba
city: Toronto
country: Canada
facility: Risk Factor Modification Centre, St. Michael's Hospital
state: Ontario
city: Quebec City
country: Canada
facility: Institute of Nutraceuticals and Functional Foods, Laval University
state: Quebec
Study officials:
affiliation: St. Michael's Hospital / University of Toronto
name: David J Jenkins, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Toronto
name: Cyril Kendall, PhD
role: STUDY_DIRECTOR
affiliation: Unity Health Toronto
name: Vladimir Vuksan, PhD
role: STUDY_DIRECTOR
affiliation: University of Manitoba
name: Peter Jones, PhD
role: STUDY_DIRECTOR
affiliation: Laval University
name: Benoit Lamarche, PhD
role: STUDY_DIRECTOR
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citation: Jenkins DJ, Wong JM, Kendall CW, Esfahani A, Ng VW, Leong TC, Faulkner DA, Vidgen E, Paul G, Mukherjea R, Krul ES, Singer W. Effect of a 6-month vegan low-carbohydrate ('Eco-Atkins') diet on cardiovascular risk factors and body weight in hyperlipidaemic adults: a randomised controlled trial. BMJ Open. 2014 Feb 5;4(2):e003505. doi: 10.1136/bmjopen-2013-003505.
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