While moderate to high fat intake is a key tenet of the paleo diet, the source of those fats should never be from refined vegetable oils. The reason being that their omega-6 to omega -3 ratios are incredibly poor. Research has shown omega-3 to be incredibly beneficial for human health in the prevention of inflammatory diseases and/or cardiovascular disease (NIH.gov). That is why salmon and fish oil are commonly recognized health foods! The reason we need to greatly increase our omega-3 intake, is that, as a population, we’re exposed to many more omega 6 oils than our ancestors ever were (The American Journal of Clinical Nutrition, 2000).
Vegetable oils, due to their shelf stability and low cost, are the most common oils found in restaurants, food service, and a majority of food products sold in stores. However, as people recognize the negative impact of these oils, there’s a shift occurring to less-refined oils with better omega-3 to 6 ratios. This has been reflected in the significant decline in sales of oils at grocery stores -- except for “alternative oils” such as coconut oil, nut oils, and animal oils like duck fat, lard, and tallow. Also, for the environment, these industrial vegetable oils (corn, soybean, etc.) are a huge driver of the monocrop agricultural system that exists today. This agricultural system is one that makes it extremely challenging for natural and/or organic farmers who want to farm the right way.