Can i use olive oil instead of vegetable oil?

Yes.: Olive oil contains oleic acid (monounsaturated fatty acid) ; several antioxidants. It fights heart disease (lowers triglycerides, ldl; protects it from free radicals ; raises hdl), also diabetes ; cancer. Best is cold pressed, first pass, unfiltered olive oil in dark bottles, used raw (mediterranean diet). For cooking use coconut oil, palm oil (healthy saturated fats) or ghee (clarified butter).