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Completed

NCT Number: NCT01351012

Canola Oil Multicentre Intervention Trial

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.

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Key information

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Richardson Centre for Functional Foods and Nutraceuticals

Winnipeg, Manitoba, R3T 2N2, Canada

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

Corn and safflower oil

Other

The oil (60 g/d/3000 kcal) is given in two daily fruit shakes for 4 weeks

Canola Oil

Other

The oil (60 g/d/3000 kcal providing 3.8 g ALA) is given in two daily fruit shakes for 4 weeks

High oleic acid canola oil

Other

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

DHA enriched high oleic acid canola oil

Other

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

Flax and safflower oil

Other

The oil (60 g/d/3000 kcal providing 6.9 g of ALA) is given in two daily fruit shakes for 4 weeks

Primary outcomes

  1. Change in endothelial function

    Time frame: 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.

    Non-invasive peripheral arterial tonometry (EndoPAT) is used to assess endothelial function.

Secondary outcomes

  1. Change in ALA conversion to EPA/DHA

    Time frame: Blood samples will be collected at the end of each of the five 4-week treatment phases over a period of nine months.

    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.

  2. Change in body composition

    Time frame: Measurements will be done at the start and end of each of the five 4-week treatment phases over a period of nine months.

    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.

  3. Change in FADS 1 & 2 mRNA and protein expression

    Time frame: Blood samples will be collected at the end of each of the five 4-week treatment phases over a nine-month period.

    mRNA and protein expression of genes/proteins involved in fatty acid metabolism will be analyzed using standard RT-PCR and immunoblotting protocols.

  4. Change in psychosocial correlates

    Time frame: 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.

    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).

  5. Change in plasma lipids and lipoproteins, inflammatory cytokines and peroxidation biomarkers

    Time frame: Blood samples are collected at the start and end of each of the five 4-week treatment phases over a nine-month period.

  6. Blood Pressure

    Time frame: Over 3 years; at baseline and endpoint of each 4-week treatment phases

    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.

Sponsors and collaborators

Lead sponsor

University of Manitoba

Other

Collaborators

  • Laval University
  • Penn State University
  • University of Toronto

Registry information

Official study title

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

Acronym: COMIT

Important dates

Study start
2010
Primary completion
2012
Study completion
2012
First posted
May 10, 2011
Registry last updated
Feb 19, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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