People use different cooking oil/medium in India.
While Ground nut Oil is used for frying Vegetables, Sesame oil is used for seasoning.
But Sesame Oil is used for every cooking activity among Brahmin house holds, Ground nut oil is used by the other communities.
Sesame oil is also used taking Oil bath by all the communities in the South.
In Kerala people use more of Coconut Oil,West Bengal,Orissa,Assam and the North East use more of Rapeseed Oil.
Sesame Oil is used for Medicinal purposes as well for almost all illnesses starting from mouth Ulcers.
Of late Olive Oil has come into India, priced high , promoted very heavily , is becoming popular
I hold the view that the art of cooking has evolved over centuries by our ancestors by trial and error taking into consideration the availability,Environment and taste.
I have tried all the Oils in all the places where I have lived and travelled.
I have found that what is used and found good for me in one place is not conducive to my health in the other place.
For example when I used Rapeseed oil in Calcutta It was agreeable to me.
But when I used it in Chennai/Bangalore it did not agree with me.
The same is the case with Wheat products.
I can use Chapati, Nan etc when I am in North India and if I use it in South India it does not agree with me as much as Rice.
Now one finds the widespread use North Indian dishes in the South and the availability of the South is becoming optional.
The entry of the South Indian foods in the North is not as much as the North Indian Foods food in the South.
But the landscape there is also changing.
Compounded to this is the use of Olive Oil, which is essentially meant for Mediterranean Climate in a tropical Country like India.
I am not sure how the interchange or change of food culture is good for Health.
I am of the view that food developed for a region is best for health.