In my most recent post I talked about fats and oils. I recommended not using vegetable oils to cook with because they breakdown into harmful products when heated. I was asked if peanut oil is okay to cook with.
In the past, it was recommended to use peanut oil for cooking because it has a high smoke point. Peanut oil was even touted as a healthy oil because, like olive oil, it is high in monounsaturated fat, considered to be the healthy fatty acids.
The problem with peanut oil is that when actually tested in lab animals, it was found to be highly atherogenic. This means it causes the build up of arterial plaques. So much so, that it continues to be routinely fed to lab animals to stimulate atherosclerosis, or the build up of plaque in the arteries, in order to study the disease itself. Because of this, I do not recommend using peanut oil anymore.
Most of this information is from: www.thepaleodiet.com