Effects of n-3 Polyunsaturated Fatty Acids and Antioxidants on Postprandial Hyperlipidemia and Vascular Function in Men

Physiological Mechanisms Underlying the Effects of PUFA and Antioxidants on Postprandial Lipemia, Oxidative Stress, Endothelial Dysfunction and Inflammation in Men

Diet has long been used as a way to provide enough nutrients to an individual in order to meet metabolic requirements. However, recent scientific advancements have suggested that beyond meeting nutrition needs, diet may also be health promoting through the modulation of various body functions. In a way, the role of nutrition has evolved from hunger satisfaction and maintenance of body integrity to the promotion of a state of well-being and prevention of important chronic diseases such as cancer, diabetes and cardiovascular disease (CVD). In recent years, n-3 polyunsaturated fatty acids (PUFA) have attracted much attention as consumption of a n-3 PUFA rich diet has been reported to reduce CVD risk. However, n-3 PUFA are also highly susceptible to free radical damage and therefore could be unable to fully exert their health benefits under an oxidative stress condition. The general objective of the present application is to investigate the mechanisms by which n-3 PUFA improve cardiovascular health in abdominal obesity and explore the potential of dietary antioxidants to modulate these effects in individuals at high risk of oxidative stress. For that purpose, we plan to study the changes in fasting and postprandial plasma lipoprotein-lipid levels, markers of lipid and lipoprotein oxidation, inflammation and endothelial dysfunction following 12 weeks of n-3 PUFA supplementation with or without low-calorie cranberry juice cocktail (as a source of antioxidants) in a group of 160 men. We feel that the present study will broaden our understanding of the physiological mechanisms underlying the beneficial effects of consuming unsaturated fatty acids and give further insights on the role of antioxidants in preserving and potentiating these cardiovascular health benefits.

Inclusion Criteria:

• Waist circumference > 90 cm
• Fasting triglycerides > 1.7 mmol/L
• No use (ever) of medications for the treatment for dyslipidemia or hypertension

Exclusion Criteria:

• Alcohol consumption > 1 drink per day i.e ~15 g of alcohol/day or the equivalent of 1 beer (12 oz or 341 mL), 1 glass of wine (4 oz or 125 mL) or 1 ounce (30 mL) of liquor.
• Chronic use of supplements (vitamins, minerals or flavonoids)
• Body mass index > 35 kg/m2
• Chronic diseases: CHD, diabetes, etc.
• Smokers (1 or more cigarette/day)
• Dyslipidemia secondary to renal insufficiency, hypothyroidism or others
• Any prior or current use of medications known to affect lipoprotein-lipid metabolism (e.g. statins, fibrates), endothelial function (hypotensive drugs). Use (ever) of anticoagulant drugs (e.g. warfarin) because of possible detrimental interaction with the consumption of cranberry juice. Current or recent (<2 weeks) use of anti-inflammatory drugs Note: If for any reason, a subject would have to go an any of these drugs during the protocol, they would be automatically dropped from the study.