Effects of n-6 PUFA-rich soybean oil, MUFA-rich olive oil and camellia seed oil on weight and cardiometabolic profiles among Chinese women: a 3-month double-blind randomized controlled-feeding trial

Previous studies have suggested that replacing saturated fat with unsaturated fat is beneficial for cardiometabolic health. However, research that directly compares the effects of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) is rare. The present 3-month, three-arm, randomized, controlled-feeding trial aimed to investigate the effects of n-6 PUFA- and MUFA-rich cooking oils on body weight and cardiometabolic profiles among middle-aged and elderly Chinese women at high cardiovascular risk. Ninety participants were recruited and randomly assigned to groups fed diets using n-6 PUFA-rich soybean oil (SO, n = 30), MUFA-rich olive oil (OO, n = 30), and MUFA-rich camellia seed oil (CSO, n = 30) as cooking oils considering traditional Chinese eating habits for 3 months. Participants were required to eat only the foods provided for lunch and dinner, and avoid intake of edible oils in breakfast. Body weight and cardiovascular profiles were measured at the baseline, middle, and end of the intervention, and group differences in changes of outcomes during intervention were examined by a linear mixed model. We found no significant difference in the changes of body weight among the SO group (mean change, 0.31 kg; 95% CI, -0.88 to 0.27), the OO group (mean change, -0.13 kg; 95% CI, -0.62 to 0.36), and the CSO group (mean change, -0.72 kg; 95% CI, -1.38 to -0.07). For secondary outcomes, the OO group showed a slight increase in HDL cholesterol (P = 0.03), while the CSO group showed greater reduction in aspartate aminotransferase (AST) (P = 0.02) when compared with the SO group. These results suggested that MUFA-rich OO and CSO exerted more favorable effects on cardiometabolic profiles among middle-aged and elderly Chinese women at high cardiovascular risk than the n-6 PUFA-rich SO.