Teeranart Utarwuthipong. Effects of consumption of soybean oil, rice bran oil, palm oil and combination of rice bran oil and palm oil on lipoprotein compositions and LDL oxidation in Thai hypercholesterolemic women. Doctoral Degree(Nutrition). Mahidol University. : Mahidol University, 2007.
Effects of consumption of soybean oil, rice bran oil, palm oil and combination of rice bran oil and palm oil on lipoprotein compositions and LDL oxidation in Thai hypercholesterolemic women
Abstract:
Objectives: To investigate the effects of consumption of soybean oil (SBO),
rice bran oil (RBO), palm oil (PO) and combination of rice bran and palm oils (RBOPO,
3:1) in Thai diet on lipoprotein composition and LDL oxidation, in phenotype II
hypercholesterolemic participants.
Method: Sixteen hypercholesterolemic women (Type IIa) participated in a
random order study. At baseline (8 wk), the diet was designed to contain carbohydrate,
protein and fat as 55, 15, 30 % of energy, cholesterol intake <300 mg/d, and used selfselected
vegetable oils 20% of energy. In experimental period (each 10 wk), individual
participants continued to have the same dietary composition while using one of 4
vegetable oils, i.e SBO (PUFA), RBO (PUFA+MUFA), PO (SFA), and RBO-PO,(3:1)
(MUFA) in a random order. At the end of each intervention, participants were
evaluated on lipid profile, lipoprotein fraction composition (cholesterol, triglyceride),
LDL fraction compositions (fatty acids), and LDL oxidation.
Results: After dietary interventions, TC and LDL-C were significantly reduced
by SBO, RBO and RBO-PO (3:1) while, HDL-C was decreased in SBO (p<0.05). TG
level was not significantly changed. A significant reduction of cholesterol in LDL1-C,
LDL2-C and LDL3-C were found after using SBO and RBO-PO (3:1) (p<0.05).
Cholesterol in LDL1-C and LDL2-C were significantly reduced by RBO while
cholesterol in LDL1-C and LDL2-C fraction increased by PO (p<0.05). The fatty acid
constituent in LDL fractions, palmitic and oleic acids were reduced by SBO but
increased by PO (p<0.05). Linoleic and linolenic acids were increased by SBO, but
reduced by PO (p<0.05). All lag time was significantly reduced by SBO, but increased
by PO (p<0.05). Lag time of LDL3-C, in particular, was increased by RBO, RBO-PO
(3:1), and PO (p<0.05).
Conclusions: Consumption of SBO and RBO-PO (3:1) enhanced reduction of
TC, LDL and cholesterol in LDL1-C, LDL2-C and LDL3-C. TC, LDL and cholesterol
in LDL1-C and LDL2-C were reduced by RBO while LDL1-C, LDL2-C and LDL3-C
were increased by PO. However, SBO decreased HDL-C. SBO had higher
susceptibility to LDL oxidation than PO, RBO-PO (3:1) and RBO.