Impact of Meal Fatty Acids on Postprandial Vascular Reactivity

The Acute Effects of Meals Rich in Saturated, Monounsaturated and n-6 Polyunsaturated Fatty Acids on Vascular Function

Cardiovascular disease (CVD) is the leading cause of death in women. Premenopausal women have a lower risk of CVD compared with men of a similar age. However, the incidence of CVD increases greatly after the menopause. The risk of heart disease is strongly associated with the health of an individual's blood vessels. It is thought that changes to the type of fat the investigators eat in their diet may affect the normal functioning and elasticity of the blood vessels, as well as affect cholesterol levels in the blood. Types of fat in the diet include monounsaturated fats (found mainly in olive oil), n-6 polyunsaturated fats (found mainly in sunflower oil) and saturated fats (found mainly in dairy products, such as butter and cheese). Since the investigators are in the fed (or postprandial) state for up to 18 hours of the day, it is important to see how these different fats affect the investigators blood vessels and blood fats over the course of the day after eating a meal. The aim of this study is to determine how consuming meals rich in saturated fats, n-6 polyunsaturated fats or monounsaturated fats influence the normal functioning and elasticity of the blood vessels throughout the day in postmenopausal women. A secondary aim is to determine the effects of these different dietary fats on a range of accepted heart disease risk markers including circulating levels of fats (lipids) and glucose in the blood.

Inclusion Criteria:

• Postmenopausal (not menstruated for at least 1 year)
• Plasma triacylglycerol (TAG) between 0.8 and 4.0 mmol/l
• Body mass index (BMI) between 18-35 kg/m2
• Total cholesterol (TC): <8 mmol/l
• Systolic blood pressure <160 mmHg and diastolic blood pressure <100 mmHg
• Non-smoker

Exclusion Criteria:

• Having suffered a myocardial infarction/stroke in the past 12 months
• Diabetic (diagnosed as fasting blood glucose >7 mmol/l) or suffering from other endocrine disorders
• Suffering from renal or bowel disease or have a history of cholestatic liver or pancreatitis
• On drug treatment for hyperlipidaemia, hypertension, inflammation or hypercoagulation
• History of alcohol abuse
• On hormone replacement therapy (HRT)
• Planning or on a weight reducing regime
• Taking nutritional supplements (e.g. fish oil, calcium)
• Anaemic: haemoglobin <11.5 g/dl