Fatty liver is a common problem in women with PCOS. In this study, EPA, an omega-3 fatty acid and a fish oil, was shown to improve the symptoms of nonalcoholic steatohepatitis (fatty liver). EPA is the fish oil that you cannot get when you rely on vegan sources of omega-3's--it's not in flax, and it's not in marine algae. Some research shows that when you've eaten enough marine algae to completely saturate your tissues, what's left can be used to make EPA, but it's not the way of getting it that the body prefers.
This is important to understand, because the vast majority of foods that are labeled as supplemented with omega-3 fatty acids either contain ALA (primarily in the form of flax) or DHA (primarily from marine algae).
The other advantage to eating fish is, that if you've put a fillet on your plate, you've likely removed another (fattier) kind of protein. That's the positive double whammy you get in seafood choices.
In my training I was always encouraged to develop good negotiation skills. In other words, if a client didn't like a certain food, to have a few other options up my sleeve that would provide equivalent nutritional value. Only when I got into omega-3 chemistry, inflammation, and PCOS, did I realize that in this one crucial area, I would have to dig my heels in and advocate that this essential nutrient was simply non-negotiable: if you don't eat fish, you miss out on total health.
Over the weekend I had an animated discussion with another dietitian who was adamant that her clients (mainly with eating disorders) simply were not going to accept this. I told her they simply would not achieve total health…and possibly total recovery. I got some resistance, but hopefully at some point this colleague will come to understand that we're here to guide our clients where they have the potential to go. We're not here to tell them what they want to hear, with the hopes that somehow health will just magically appear.
Tanaka N, Sano K, Horiuchi A, Tanaka E, Kiyosawa K, Aoyama T. Highly Purified Eicosapentaenoic Acid Treatment Improves Nonalcoholic Steatohepatitis. J Clin Gastroenterol. 2008 Apr;42(4):413-418.