Saturated Fatty Acids and HDL Metabolism

Effects of C16:0 Versus C18:0 on HDL Metabolism and Other Cardiometabolic Risk Markers: A Dietary Intervention Study in Healthy Normal-weight and Overweight Subjects

The purpose of this study is to determine whether palmitic acid (C16:0) and stearic acid (C18:0) have different effects on HDL metabolism during the fasted state.

Study design:

Double blind, randomized, cross-over study with two different diets: one diet will be high in palmitic acid (C16:0) and the other diet will be high in stearic acid (C18:0). Subjects will receive both diets for 4 weeks with a wash-out period of 4-6 weeks in between. Contrast in the intakes of palmitic acid and stearic acid is 6% of energy. A postprandial test will be carried out at the end of each dietary period.

Study population:

Accounting for a dropout rate of 20%, 40 healthy men and postmenopausal women, aged between 45 and 70 year, having a BMI (body mass index) between ≥ 18.0 and ≤ 30.0 kg/m2 will be recruited.

Inclusion Criteria:

• Apparently healthy men and post-menopausal women (post-menopausal for at least one year) as judged by study physician
• BMI ≥ 18.0 and ≤ 30.0 kg/m2
• Aged between 45 and 70 years
• Willing to comply to study protocol during study
• Having a general practitioner
• Agreeing to be informed about medically relevant personal test-results by a physician
• Informed consent signed
• Accessible veins on arms as determined by examination at screening

Exclusion Criteria:

• Having a medical condition which might impact study measurements
• Use of over-the-counter and prescribed medication, which may interfere with study measurements
• Use of oral antibiotics in 40 days or less prior to the start of the study;
• Use of food supplements or plant-sterol/stanol-enriched foods or supplements in the three months prior to the screening and/or during the study;
• Reported alcohol consumption ≥ 10 units/week (female) or ≥ 14 units/week (male);
• Reported intense sporting activities ≥ 10 hours/week;
• Reported weight loss or gain of 3 kg or more during a period of 2 months prior to screening
• Regular smokers (at least one cigarette (or equivalent) daily or >7 cigarettes (or equivalent) weekly. Smokers who cannot comfortably restrain from smoking for up to 2 days will also be excluded
• Reported dietary habits: medically prescribed diet, allergy/intolerance to test products that will be provided during the study
• Blood donation in the past 3 months
• Drug abuse
• Reported participation in another nutritional or biomedical trial 3 months prior to screening
• Fasting triacylglycerol concentrations at screening: ≥ 4.5 mmol/L
• Serum lipids: treatment recommended according to the "Multidisciplinary guidelines Cardiovascular risk management"
• Fasting HbA1c ≥ 48 mmol/mol (or 6.5%)