How do we know these are the best oils?
Well, you can google them. Not sure where I originally picked up the ideas that these are good. I tend to just wander through the internet following my nose and adding generous pinches of salt, as necessary.
However, (from some very quick googling myself):
Coconut oil was recommended by the health freaks - er... Health conscious individuals who promote green smoothies. Something to do with beneficial fatty acids. I started using it in cooking and smoothies, and LOVE it.
http://authoritynutrition.com/top-10-evidence-based-health-benefits-of-coconut-oil/
Butter's benefits vary depending on what the cow has been eating. Not surprising, eh? Grass fed butter contains vit K2, which apparently helps to de calcify arteries.
http://authoritynutrition.com/grass-fed-butter-superfood-for-the-heart/
Fish oils (cod liver, salmon, krill, and some new one made from (i think) squid, have great proportions of the omegas, helping brain and nearly everything else!
Likewise hemp and linseed
And olive oil, extra virgin,
http://www.mayoclinic.org/healthy-l...xpert-answers/food-and-nutrition/faq-20058439
Have a google. Of course some of the information is conflicting, but my attitude is that I won't touch processed fats, If I can help it. And those vile cholesterol reducing margarine abominations are IMHO worse than eating engine oil.
Having ranted, I would like to point out (before someone else does) that I am currently eating 2oz of processed cheese a day. But it is all in the interests of science and the reduction of my dawn phenomenon. Honest guv'nor!