Eating fish has been found in several studies to be heart-healthy, lowering blood pressure, reducing inflammation, and reducing the risk of sudden death. Now, a study published in a recent edition of Circulation suggests that lean fish (white fish such as cod) may not have the same cardiac benefits as fatty fish (tuna or salmon.)
Investigators from Boston's Brigham and Women's Hospital, using data from the Cardiovascular Health Study, compared the rate and type of fish consumption to the incidence of atrial fibrillation. They found that people who ate tuna or other oily fish at least five times per week had a reduced incidence of atrial fibrillation compared to patients who either ate little fish or who ate only white fish.
This finding is consistent with the fact that eating fatty fish appears to increase the level of omega-3 fatty acids, whereas eating fried fish or fish burgers (almost exclusively white fish) does not. The omega-3 fatty acids are thought to provide the cardiac protective effects from eating fish.
The bottom line
It may be that in assembling our heart-healthy diet, we may need to choose only oily fish (while avoiding the oily fish that contain excess mercury). The kinds of fish most commonly eaten -the white fish used for fried fish, for fish sticks, and for fish burgers - may not apply.
