I have read many discussions on this and some a lot of people disagree but most doctors are now saying that flax seed oil is almost of no benifit. Befor everyone flamesm e let me just say why. Because it is a plant based oil it lacks certain things the fish oil has. IT SAYS IT HAS IT BUT DOES NOT. It is not an outright lie. It is like saying a carrot has vitamine A. It doesn't. It has Beta carotine which our body can convert to Vitamine A as needed. Same with Flax oil. It has something out body has to convert to ( I think omega 6 ). But once our body converts it you get like 1/50th of what you actually ingested. That is like one drop. Flax is better than nothing but not nearly as good as fish oil. Fish oil has the Omega 6 all ready to go and your body uses all of it. The only real concern with fish oil is how much mercury is still in it (but they has processes now that can remove like 99.9 %. And also burping fish taste. If you can get past those go with fish oil.
I read these deebates long ago so I am not sure the nutrient in question is even the omega 6 acids but it is something like that