Eating fish in moderation is healthy for you and the fish oil can help improve your brain health and eating fish may even prevent dementia.
But if you eat too much fish you could get mercury poisoning which is not a good thing.
Fish contain mercury and eating too much fish or eating fish everyday can cause an increase in the mercury levels in your body.
Then that leads to mercury poisoning which if not treated can be deadly.
Also fish and fish oil is also very high in vitamin A, which can be dangerous in large amounts.
But fish and fish oil in small amounts is okay and healthy for you.
Just don't eat fish everyday and you'll be okay.