Effects of palm oil and dietary cholesterol on plasma lipoproteins: results from a dietary crossover trial in free-living subjects

OBJECTIVE: To study the effects of palm oil (PO) and egg consumption (E) on plasma lipoproteins. DESIGN: Randomized crossover trial. SETTING: Free-living subjects. SUBJECTS: Twenty-eight healthy male students aged 20-34 y. INTERVENTIONS: Four typical Colombian diets (10 878 kJ/day; 57% energy in carbohydrates, 12% energy in proteins and 31% energy in fats) were consumed for 4 weeks. The HPOLC diet was high in PO (8.8% energy as palmitic acid, PA) and low in eggs (181.2 mg/kJ of dietary cholesterol, DC); the HPOHC diet was high in PO and high in eggs (866.1 mg/kJ of DC); the MPOMC diet was moderate in PO (6.3% energy as PA) and moderate in eggs (581.6 mg/kJ of DC); and the LOPOMC diet had no PO and was moderate in eggs (543.9 mg/kJ of DC). MAIN OUTCOME: Total (TC), low density (LDL-c), and high density lipoprotein cholesterol (HDL-c), and triacylglycerols (TAG) were measured on a pool of three fasting blood samples collected in consecutive days the last week of each diet. RESULTS: Comparison of the HPOHC and HPOLC diets showed increases in TC and LDL-c of 0.21 (P=0.01), and 0.16 mmol/l (P=0.05). Comparison of LOPOMC and MPOMC diets showed increases in TC and LDL-c of 0.39 (P<0.001), and 0.38 mmol/l (P<0.001), respectively. No significant changes in HDL-c or TAG were observed. CONCLUSIONS: Our findings suggest that non-extreme short-term changes in PO and DC consumption lead to significant elevations in plasma TC and LDL-c. SPONSORSHIP: CENIPALMA, Fundación Cardiovascular del Oriente Colombiano, Universidad Industrial de Santander.