The Acute Effects of Meals Rich in Saturated, Monounsaturated and n-6 Polyunsaturated Fatty Acids on Vascular Function
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Reading
- Enrollment
- 32
- Locations
- 1
- Primary Endpoint
- Change from baseline in vascular reactivity measured by flow-mediated dilatation (FMD)
Study Overview
Brief Summary
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.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Prevention
- Masking
- Triple (Participant, Investigator, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 65 Years (Adult, Older Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- Yes
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
Arms & Interventions
Meal rich in saturated fats
Subjects are asked to consume a breakfast (0 min) and lunch (330 min) rich in saturated fats
Intervention: Saturated fat (Dietary Supplement)
Meal rich in monounsaturated fats
Subjects are asked to consume a breakfast (0 min) and lunch (330 min) rich in monounsaturated fats
Intervention: Monounsaturated fat (Dietary Supplement)
Meal rich in n-6 polyunsaturated fats
Subjects are asked to consume a breakfast (0 min) and lunch (330 min) rich in n-6 polyunsaturated fats
Intervention: n-6 polyunsaturated fat (Dietary Supplement)
Outcomes
Primary Outcomes
Change from baseline in vascular reactivity measured by flow-mediated dilatation (FMD)
Time Frame: Acute study: measured at 0 (baseline), 180, 300 and 420 min
Secondary Outcomes
- Change from baseline in blood pressure (systolic blood pressure, diastolic blood pressure and pulse pressure)(Acute study: taken at 0 (baseline), 240 and 450 min)
- Change from baseline in arterial stiffness measured by digital volume pulse (stiffness index and reflection index)(Acute study: taken at 0 (baseline), 240 amd 450 min)
- Change from baseline in nitric oxide (total plasma nitrates and nitrites)(Acute study: 0 (baseline), 180, 300 and 420 min)
- Change from baseline in plasma markers of endothelial activation (e.g. E-selectin, P-selectin, vascular cell adhesion molecule (VCAM-1))(Acute study: 0 (baseline), 180, 300 and 420 min)
- Change from baseline in markers of insulin resistance (glucose, insulin, indices of insulin resistance/sensitivity)(Acute study: taken at 30 min intervals between 0 min (baseline) and 480 min)
- Change from baseline in plasma phospholipid fatty acid composition(Acute study: 0 (baseline), 180, 300 and 420 min)
- Change from baseline in vascular reactivity measured by laser Doppler imaging with iontophoresis of acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent)(Acute study: measured at 0 (baseline), 240 and 450 min)
- Change from baseline in plasma lipids (primarily triacylglycerol, apolipoprotein B and non-esterified fatty acids)(Acute study: taken at 30 min intervals between 0 min (baseline) and 480 min)
Investigators
Julie Lovegrove
Professor Julie Lovegrove
University of Reading