Abstract

Background: Vegetable oil is widely used for frying food, especially palm oil. Repeated use of cooking oil is often unavoidable. Frying is known to change cis unsaturated fatty acids into trans. However, the effects of repeated frying of olive oil compared to palm oil is still not widely known.

Objective: The objective of this study is to determine the effect of repeated frying of palm oil and olive oil on survival rate and blood glucose pattern in mice.

Methods: There were 39 adult male mice divided into 3 groups: control (n=12), palm (n=13), and olive (n=14). Control group was given oral gavage of water during research. Palm and olive oils were given in palm and olive groups. Before given to mice, palm and olive oils were used for frying sweet potatoes 5 times then given to mice for 4 weeks. At the beginning and after treatment, fasting blood glucose (FBG), the 2 hours postprandial oral glucose tolerance test (2-h OGTT) blood glucose level were measured and then area under the curve (AUC) was also calculated.

Results: After 4 weeks of treatment, there were 9 mice that remained alive in the control group, 9 mice in the palm group, and 11 mice in the olive group. The survival rate was 75% in the control group, 69.23% in the palm group, and 78.57% in the olive group. Weight gain was significantly different between pre and post in the control and olive groups (p=0.009; p=0.004). FBG level increased significantly in the palm group compared to the control group (P<0.05). The 2-h OGTT glucose level increased significantly compared to pre in the control group (p=0.004) and olive group (p=0.000). AUC of the olive group increased significantly compared to the control group (p=0.0039).

Conclusion: Consumption of olive oil which is fried repeatedly and given for 4 weeks shows a better survival rate than palm oil.

Keywords: Olive, palm, oil, glucose, cis fat, trans fat, mice, health.

Graphical Abstract