There's been a little controversy happening lately over what role, if any, fish oil should have in a 'healthy diet'. I've been taking the stuff myself since around 2003, after reading much the same research that drove everybody else to it. Fish oil, or more precisely the omega-3 EPA and DHA in it, can sometimes seem like a miracle drug, with benefits for everything from heart disease to joint health, fat metabolism and brain function.
There's a lot of information out there as a quick scan of Pubmed will reveal. It's safe to say that the scientific consensus -- which, however tentative and provisional, is the only real 'truth filter' we have with regard to health matters -- is on the side of at least a moderate intake of omega-3 fats.
But then we have a spanner in the works in the form of Ray Peat. Peat is an outsider who has a large portfolio of writings on human health and nutrition, and while I know little about him, he does touch on these topics in an interesting way. Relevant here is his article "The Great Fish Oil Experiment". Here, Peat says exactly the opposite: the consensus is misleading, biased, and these polyunsaturated fats (a category which includes the omega-3 fatty acids) are actually dangerous.
My interest in fish oil has little to do with cardiovascular disease or joint health. I am, however, keen on it for reasons of mental health. Over the last few years, I've noticed a strong connection between my fish oil intake -- and lack thereof -- and my sense of well-being. The spells where I've gone without fish oil for longer than a few months have been, to be blunt about it, hellish. It starts to feel like I'm disintegrating from the inside out, and it's not a fun place to be.
The last few months of 2010 were one such episode, and on resuming fish oil the whole thing reversed itself in a matter of days. More recently, I took a month or so off after a few us of started toying with Peat's recommendations, and it wasn't long before the same symptoms returned, and then quickly vanished after getting omega-3 back in the diet. Needless to say, I'm sold -- even if it's a placebo effect, quality of life is worth it. Fortunately there are plenty of hints in the research, by way of actual clinical trials and meta-analyses, that bolster my findings so there's a good chance I'm not making it all up.
Here's the thing, though. I do fine on low doses, talking 5-12g per day, and that's roughly what these studies are suggesting. My impression is that, since my diet isn't particularly PUFA-rich, that amount is reversing whatever deficiency I have, topping up the tank so to speak.
But how common is it now to see people taking insane mega-doses of fish oil, upwards of 30-40g a day with the typical American thought process: some is good so LET'S TAKE ALL OF IT!! Peat is right, I think, to point out that these are complex systems that do not respond well to that logic. Some can be good, and more can be lethal. We would do well to bear that in mind, rather than applying the usual blunt instrument of medicalizing all our problems, as if everything 'wrong' needs a pill (or miracle food or what have you) to solve it.
This is a fine instance to demonstrate why we need to be aware of the conditional nature of science's discoveries, rather than uncritical acceptance, and to exercise a little epistemic humility with respect to what we believe to be true. This isn't a religion, and I think Peat is raising points that demand consideration. I will say that I'm not enamored of the narrative defenses he deploys, the accusations of scientific misconduct and so on, and I believe that hurts his argument (and if the well is so poisoned, on what grounds can we believe what Peat is saying when he drinks the same water?).
That said, I'm being more cautious of my fish oil intake, too.