Now let me tell you what i do in my practice. 10 years and about 12,000 cases. Does that make me an expert, I think so, but argue if you want.
First Fish oil is the gold standard in reduction of inflammation through the entire body. Why? EPA inhibits 5 desaturase from converting DHGLA to arachidonic acid and then blocks the COX 2 step to convert to prostaglandin E2, thromboxanes, and blocks 5LOX from making leukotrienes.
If anyone wants to argue with my about lipid biochemistry then we can do that.
Next insulin shunts EPA's inhibition of this enzyme so eating lots of starchy or sugary foods increases OMEGA 6 conversion to DHGLA- AA- PE2 - Leukotrienes.
The oils are both good. The reason flax works well is because of the lignans, and not so much its EFA profile. Lignans also block DHGLA. Fish oil works by brute force of EPA.
Both are good but for different reasons.
That being said I use Fish oil becuase many individuals need EPA and DHA for brains, joints skin et all and have an abundance of Omega 6 fats in their diets already.
It also takes 5 enzymes to convert ALA to EPA and another couple of enzymes to Convery EPA to DHA. So i bypass the entire system and give fish oil which supplies the EFA already.
Too many Omega 6 fats , which are found in flax, overpower the Omega 3 side and the ratio gets out of tilt.
So for joints its a pickem-- both work, for brains its a fish oil blowout.
That being said, i think Flax is still a healthy oil, and is a great replacement for individuals who cant or wont do fish oil.
both inhibit inflammation, but the research shows that EPA in fish oil is the gold standard, and there are about 1000 or so studies showing its effectiveness.
I also use fish oil, not necessarily cod liver oil , for neurological disorders due to the high DHA level. I have had remarkable success with Manic Depression, Bipolar Disorder, Depression, Learning difficulties, ADHD, Alzeimers, Dementia and Cognitive disorders including aphasia.
So. you guys put down the guns. If someone is doing high dose flax and having success then good. Flax works well for menapausal women, the lignans help.
I still use fish oil in tandem with Flax for the nervous system.