Ray Peat has been saying for years that they're not only not essential, but 'toxic': http://raypeat.com/articles/articles/fishoil.shtml http://raypeat.com/articles/articles/unsaturated-oils.shtml http://raypeat.com/articles/nutrition/oils-in-context.shtml He claims they're toxic to the mitochondria, they suppress immune function, and on and on. Of course many (like Mary Enig for example) have argued he cherry-picks his studies, and is wrong, but then again, he has supporters who have claimed his ideas have helped them improve their health (including those with lyme, mold toxicity, heavy metal issues, etc.). ???