Metabolic Syndrome
Conditions
Keywords
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
Brief summary
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
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.
Interventions
OTHERCorn and safflower oil
The oil (60 g/d/3000 kcal) is given in two daily fruit shakes for 4 weeks
OTHERCanola oil
The oil (60 g/d/3000 kcal providing 3.8 g ALA) is given in two daily fruit shakes for 4 weeks
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
OTHERDHA enriched high oleic acid canola oil
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
OTHERFlax and safflower oil
The oil (60 g/d/3000 kcal providing 6.9 g of ALA) is given in two daily fruit shakes for 4 weeks
Sponsors
University of Toronto
Penn State University
Laval University
University of Manitoba
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in 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. | Non-invasive peripheral arterial tonometry (EndoPAT) is used to assess endothelial function. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in body composition | 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. |
| Change in FADS 1 & 2 mRNA and protein expression | 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. |
| Change in ALA conversion to EPA/DHA | 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. |
| 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 | 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. |
| Change in psychosocial correlates | 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). |
Countries
Canada
Outcome results
None listed