Canola Oil Multicentre Intervention Trial (COMIT)
Condition: Cardiovascular Disease
MeSH terms: Cardiovascular Diseases
Study type: Interventional

Summary: 
      The objectives of this study are to examine how the consumption of treatment oils (including
      canola oil, DHA enriched canola-oil, high oleic acid canola oil, flax oil, and safflower oil)
      influence endothelial function, inflammation, oxidation, body composition, and plasma
      lipoprotein characterization.
    

Detailed description: 
      The consequence of total fat consumption on circulating plasma lipids and the incidence of
      cardiovascular disease has long been a central theme in nutrition research. Less well known
      is the influence of specific fatty acids on vascular endothelial function and the oxidative
      and inflammatory responses characteristic of atherogenesis. Omega 3 ( ω-3) fatty acids,
      including plant derived alpha-linolenic acid (18:3n-3, ALA) and marine derived
      eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) have been shown to
      effectively modulate multiple cardiovascular risk factors in epidemiological, animal model
      and human clinical investigations. ALA is most commonly consumed as a major component of
      dietary canola and flaxseed oils and has a recommended intake of 1.1 and 1.6 g/d for women
      and men, respectively. EPA and DHA are consumed as fatty fish or fish oil and algae
      supplements with current recommended intakes of 500 mg/d (combined EPA and DHA).

      ALA is thought to improve cardiovascular health by modulating circulating lipid
      concentrations, altering membrane structure and function by enhancing the total ω-3 fatty
      acid content of cell membrane phospholipids, and reducing inflammatory reactions by blocking
      the formation of arachidonic acid derived eicosanoids. However, there are extensive knowledge
      gaps in our understanding of the molecular mechanisms and clinical efficacy of ω-3 fatty
      acids in human health and disease prevention. Therefore, the purpose of this study is to
      further examine these relationships.

      Feeding protocol and study treatments:

      The study will proceed as a double blind, randomized cross-over controlled feeding study.
      Each treatment phase will be 30 days in duration, separated by 4-week washout periods.
      Subjects will consume a fixed composition of a precisely controlled basal, weight-maintaining
      diet (35% energy from fat, 50% carbohydrate, and 15% protein) supplemented with 60g/d of the
      following treatment oils: 1) canola oil; 2) DHA enriched canola-oil; 3) high oleic acid
      canola oil; 4) flax/corn oil (40:60); or 5) safflower/corn oil (75:25). Study diets will be
      prepared in a metabolic kitchen facility at each clinical site. Three isocaloric meals will
      be prepared each day for every subject. A 7-day rotating menu cycle will be used. Subjects
      will consume at least 1 of 3 daily meals under supervision. The other meals will be prepared
      and packed for every subject to be taken out. The study control and intervention oils will be
      delivered in milkshakes provided twice daily. Subjects will be instructed to consume only the
      prepared meals and limit their intake of alcohol to 2 drinks/week and caffeinated calorie
      free beverages to 40oz (5 drinks) per day. Diets will be planned for every subject according
      to his/her energy requirements and will be nutritionally adequate.
    

Intervention name(s): Canola Oil; High Oleic Acid + DHA Canola Oil; High Oleic Acid Canola Oil; Flax Oil; Safflower Oil
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): 60g Canola oil daily per 3000kcal diet provided in a supplemental shake; 60g high oleic acid canola oil + DHA daily per 3000kcal provided in a supplemental shake; 60g high oleic acid canola oil daily per 3000kcal provided in a supplemental shake; 36g flax oil + 24g safflower oil daily per 3000kcal provided in a supplemental shake; 45g safflower oil + 15g corn oil daily per 3000kcal provided in a supplemental shake
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Care Provider)
Primary purpose: Prevention
Keywords: Cardiovascular disease; Omega-3 fatty acids; Inflammation; Endothelial function; Canola oil