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.

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.

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)