Also I heard since fish are cold blooded the Omega 3 doesn’t oxidize in their body but since we’re warm blooded then it might oxidize in our body?
Genuine questions.
Some omega 3’s can be lost in the cooking process. It generally depends on the method of cooking, with dry heat causing more damage as opposed to moist heat.
In my readings, I have seen that baking fish in the oven retains more than pan frying on the stove for instance. And poaching/steaming will retain even more than those. Other methods like deep frying are particularly harmful to the omega 3 content.