A 10 year study of 84,493 post-menopausal women reveal that those who frequently ate steamed or broiled dark fish such as salmom, mackerel or bluefish had a a 30% lower risk of developing heart failure. On the other hand, those who ate fried fish once a week had a 50% higher risk of incident of heart failure. The study suggests that not only is it important to eat darker fish which are rich in Omega 3 fatty acids, but the preparation of the fish was equally important. Frying fish may introduce saturated fats and trans fats that negate the benefits of the Omega- 3 fatty acids found in fish. For good heart health, try to incorporate fish in your diet and eat more of the dark fish as opposed to sole, snapper, cod which are considered white fish.  

See article: http://www.medscape.com/viewarticle/743457?sssdmh=dm1.690758&src=nldne