Uriah

The obvious association that exists between fish consumption and omega-3 level is not as obvious as it first might appear: for example a Korean study found only a very weak correlation of .269 between fish intake and EPA+DHA in serum.

A study done on Finnish fishermen looked at a populations that consumes fish at about the average Japanese level (70kg per year) and yet their circulating omega-3s (7% of total fat) were lower than 6 out of 7 general Japanese samples and only about half the Japanese peak.

In other words, it is very difficult for a typical European to match Japanese omega-3 levels, even when eating an ungodly amount of fish.

There’s likely a feedback loop here: populations that eat more fish evolve with time to better process EPA+DHA and this makes the beneficial physical and mental effects of stuff much more salient for them.

Someone would need to demonstrate this, but I think I’ve noticed a tendency for the Japanese to remain relatively immune to diminishing marginal returns here: every extra fish eaten does less and less for an Englishman, but there’s no end to what the Japanese can metabolize.

Population geneticists have detected recent strong natural selection acting on carbohydrate metabolism in Europeans and genes which facilitate ketogenesis in the meat eating peoples of the Arctic. I think it’s unlikely that something similar has not gone on in the Japanese.

There has a lot of recent research on the cognitive effects ofomega-3 and the most rock solid findings are that they dramatically aggression and the risk of developing schizophrenia. There’s a national correlation -0.63 (strong) between seafood consumption and homicide rate.