That is my understanding also. That said, I have started eating fish again on the advice of my doctor: I have been on the Eat to Live diet (no red meat, little meat in general, no dairy, no sugar that is not in whole fruit, lots of seeds and nuts). My doctor likes the diet but asked me to add two servings a week of oily fish high in omega 3. Expensive, but there are a few brands of Norwegian sardines packed in water that taste good to me.

I won't eat fish in a restaurant or from a grocery store chain.