The studies compared seafood eating folks vs o3 supplementation and that is rather a correlation as I might suspect that people who eat fish regularly are in general more health aware as opposed to people taking supplements as a quick fix. So I might coclude that there is nothing intrinsically wrong with epa/dha supplements lowering its efficency (as long as they are processed under good manufacturing pracrice).
But I agree that eating cold water sea food that is low on the food chain is best.
And here's the reason why studies, especially about nutrition or training, shouldn't be taken as the end-all-be-all.
They simply can't say whether the better blood work etc. is a product of eating fish instead of supping oil or just a product of their overall lifestyle. But since it's a study about fish vs. fish oil they conclude eating fish is better than supping fish oil.
I'm not doubting that eating fresh fish actually is better, but criticizing the way most of the studys come to a certain conclusion and label it as proven or given.
I like examples
so here's one:
Take a number of people.
We want to compare eating an apple a day vs. taking a vitamin pill.
The people are all exactly the same, like clones (which isn't possible in real life)
I control their diet, their training, sleep, exposure to sun etc., everything (which isn't possible in real life either).
It just so happens that a lot of the people eating the apple live in the city, while most of the pill takers live in the countryside.
At the end of the study the pill takers have better bloodwork than the apple eaters. Maybe it's because pills are better than apples or maybe it's because most of the pill takers live outside the city and breath fresh air instead of the polluted air in the city.
It's a study about apples vs. pills, not about city vs. country. And hey maybe it was even at least partly financed by a company selling pills.
I'll conclude that pills are better than apples and if you doubt it I have all the bloodwork etc. to "prove" I'm right.
In real life I don't have participants that are genetically 100% the same and I can't control their every move etc. So instead of having that one variable (city vs. countryside) I end up with thousands, maybe even millions of variables that could alter the results.
This problem is somewhat alleviated by using a big number of participants and other methods. It still remains fact that the end results can be altered by a lot of factors and that at the end the author of the study can "manipulate" the result to prove his/her point (e.g. pills are better than apples, while the real cause might be fresh vs. polluted air).
I don't want to say that we should get rid of studys. That's clearly not my intention. We need them for scientific progress.
Just look out and be sceptical about the things you read in them.