Canola Oil Multicentre Intervention Trial

Study Overview
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Brief Summary
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The purpose of the study is to examine how the consumption of different dietary oil varieties affects a broad range of metabolic responses that are important in the development of cardiovascular diseases. This study will examine the relationship between dietary oil consumption and arterial function, blood fat content, and blood markers of cardiovascular disease risk. Additionally, the efficiency of the body in converting fat from dietary oils into other specific fat compounds with know health benefits will be examined. Also, the correlation between psychosocial parameters and vascular function will be studied.

Detailed Description
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Although consumption of omega-3 fatty acids favorably modulate circulating lipids and arterial health, there is confusion surrounding the specific health benefits of plant based alpha-linolenic acid (ALA) versus marine derived eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This research will examine the health benefits of ALA from consumption of diets rich in canola oil, novel monounsaturated fatty acid (MUFA) and DHA enriched canola oils, and flax oil compared with a control diet representative of North American diets rich in omega-6 and saturated fats. Treatment oils will be examined for potential influence on endothelial dysfunction, inflammation, oxidation, body composition, and plasma lipoprotein characterization. Furthermore, in an effort to elucidate the genetic factors that promote ALA conversion to EPA/DHA and strengthen the role of ALA in cardiovascular health, a major objective is to correlate common genetic variants in the fatty acid desaturase 1 (FADS1) and fatty acid desaturase 2 (FADS2) gene cluster with ALA conversion to EPA/DHA and n-3 fatty acid composition of serum phospholipids in response to consumption of the treatment oils. Besides, psychosocial predictors of vascular function will be investigated.

Official Title
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Canola and Flax Oils in Modulation of Vascular Function and Biomarkers of Cardiovascular Disease Risk

Conditions
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Metabolic Syndrome

Intervention / Treatment
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* Other: Corn and safflower oil
* Other: Canola oil
* Other: High oleic acid canola oil
* Other: DHA enriched high oleic acid canola oil
* Other: Flax and safflower oil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Waist circumference ≥94 cm (males) or ≥80 cm (females) plus at least one of the following: Triglycerides ≥1.7 mmol/L High density lipoprotein (HDL) cholesterol <1 mmol/L (males) or <1.3 mmol/L (females) Low density lipoprotein (LDL) cholesterol ≥3.5 mmol/L Blood pressure ≥130 mmHg (systolic) and/or ≥85 mmHg (diastolic) Glucose ≥5.5 mmol/L Exclusion Criteria: Thyroid disease Diabetes mellitus Kidney disease Liver disease Smoking Heavy drinking Use of medication known to affect lipid metabolism during the last 3 months(cholestyramine, colestipol, niacin, clofibrate, gemfibrozil, probucol, HMG CoA reductase inhibitors)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Corn and safflower oil<br> | Other: Corn and safflower oil<br>* The oil (60 g/d/3000 kcal) is given in two daily fruit shakes for 4 weeks<br>|
| Active Comparator: Canola oil<br> | Other: Canola oil<br>* The oil (60 g/d/3000 kcal providing 3.8 g ALA) is given in two daily fruit shakes for 4 weeks<br>|
| Active Comparator: High oleic acid canola oil<br> | Other: High oleic acid canola oil<br>* The oil (60 g/d/3000 kcal providing 41.2 g oleic acid and 1.2 g ALA) is given in two daily fruit shakes for 4 weeks<br>|
| Active Comparator: DHA enriched high oleic acid canola oil<br> | Other: DHA enriched high oleic acid canola oil<br>* The oil (60 g/d/3000 kcal providing 1.2 g of ALA and 3.6 g of DHA) is given in two daily fruit shakes for 4 weeks<br>|
| Active Comparator: Flax and safflower oil<br> | Other: Flax and safflower oil<br>* The oil (60 g/d/3000 kcal providing 6.9 g of ALA) is given in two daily fruit shakes for 4 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in endothelial function | Non-invasive peripheral arterial tonometry (EndoPAT) is used to assess endothelial function. | Endothelial function will be measured at baseline and at the end of each of the five 4-week treatment phases over a period of nine months. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in ALA conversion to EPA/DHA | On day 28 of each experimental phase, a fasting baseline blood sample is taken prior to administration of an oral dose of deuterium oxide containing a higher than normal proportion of the hydrogen isotope deuterium (2H). Fasting blood samples will be obtained 24 h following the tracer dose. Enrichment of 2H in EPA and DHA plasma triglycerides, non-esterified fatty acids, and phosphatidylcholine will be measured by GC-combustion isotope-ratio mass spectrometry. | Blood samples will be collected at the end of each of the five 4-week treatment phases over a period of nine months. | 
| Change in body composition | Changes in body composition will be assessed using dual-energy X-ray absorptiometry (DXA) scans. Also, a MRI scan will be performed on each subject at the start of the study. | Measurements will be done at the start and end of each of the five 4-week treatment phases over a period of nine months. | 
| Change in FADS 1 & 2 mRNA and protein expression | mRNA and protein expression of genes/proteins involved in fatty acid metabolism will be analyzed using standard RT-PCR and immunoblotting protocols. | Blood samples will be collected at the end of each of the five 4-week treatment phases over a nine-month period. | 
| Change in psychosocial correlates | Subjects will complete questionnaires regarding their mood and recent sleep (state questionnaires) and a questionnaire regarding their overall mood, social support and behaviors (trait questionnaire). | Measurements are done at baseline, at the start of the fifth treatment phase and at the end of each of the five 4-week treatment phases. | 
| Change in plasma lipids and lipoproteins, inflammatory cytokines and peroxidation biomarkers |  | Blood samples are collected at the start and end of each of the five 4-week treatment phases over a nine-month period. | 
| Blood Pressure | Blood pressure data (change in both systolic and diastolic) was taken 3 times at the baseline and endpoint of each phase of the trial. 2nd and 3rd measures were averaged. | Over 3 years; at baseline and endpoint of each 4-week treatment phases | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Canola oil, High oleic canola oil, Flax oil, ALA, DHA, Metabolic syndrome, Cardiovascular disease, Endothelial function, FADS1, Gut microbiome, Body composition, Psychosocial status, Cholesterol, Lipids, Lipoproteins, Inflammation, Lipid peroxidation