Objectives: Plant oil for cooking typically provides 40% to 50% of dietary fat, 65% of linoleic acid, 44% of α-linolenic acid and 41% of oleic acid in the Chinese diet. However, the comparative effects of fatty acids derived from plant oil on cardiovascular risk factors in Chinese are still inconclusive. Hence, the aim of this study is to investigate whether cardiovascular risk factors are altered depending on various types of plant oils such as peanut oil rich in oleic acid, corn oil rich in linoleic acid, and blend oil fortified by α-linolenic acid.
Design: A randomized, double-blinded, parallel-designed trial.
Setting: The First and the Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Participants: A total of 251 volunteers with fasting blood total cholesterol between 5.13 and 8.00 mmol L-1 were enrolled.
Intervention: Volunteers received peanut oil, corn oil or blend oil to use for cooking for one year.
Main outcome measures: The erythrocyte membrane fatty acid composition, fasting plasma lipids, glucose and insulin concentrations and high sensitivity C-reactive protein (hsCRP) levels were measured before, during and after the intervention. The level of α-linolenic acid in erythrocyte membranes was significantly increased in the blend oil group after the intervention (P < 0.001). The level of other fatty acids did not show any statistically significant differences between the three groups. No significant differences were observed in the concentrations of fasting plasma lipids, hsCRP, glucose, and insulin among the three groups using different types of plant oils.
Conclusions: The results suggest that although ingesting cooking oil with different fatty acid composition for one year could change erythrocyte membrane fatty acid compositions, it did not significantly modify cardiovascular risk factors in moderately hypercholesteremic people.