I read the composition of Mustard oil it seems to me to be very good.
Saturated fat - 12%
Monosaturated - 60%
Omega - 6 (linoleic) - 15%
Omega - 3 (alpha linolenic) - 6%
It seems to be the only oil which can be bought in large quantities with 1:2.5 omega 6 to omega 3 ratio.
http://en.wikipedia.org/wiki/Mustard_oil
In North India Mustard oil along with Clarified butter (Ghee) was the major component of fat in our diet (before the advent of processed crap vegetable oils). Our diet being Vegetarian in nature there is no grass fed beef (actually for hindus eating beef is sacrilege, like eating your own mother) or Fish as an Omega 3 source.
It seems the Mustard oil might be the reason we have survived so long without much Meat. It might have been mainly responsible for providing the essential fatty acids in our diet.
It also has a lot of Anti bacterial and Anti Fungal agents which are necessary for our survival in the hot regions. In our area Mustard oil and Turmeric are used a lot for this purpose. It is used a lot for pickling.
It also has a very pungent taste which makes it difficult for other people to use it.
What do you people think about it?