How Fish Oil Helps the Heart: Now We Know

For years, everyone who set food in a Whole Foods market has heard that eating fish that is rich in Omega-3 fatty acids  (mackerel, salmon, and tuna) is good for the heart, but few people knew why. Now we do: It’s the electricity, stupid. A study of more than 5,000 people over the age of 65 has shown that eating fish is associated with a lower
heart rate, a slower interval between when the heart received a
signal to pump blood and when blood was pumped, and a lower
likelihood that the heart would take a long time to reset its
electrical system after a beat. That last effect, Forbes reports, is more important than many people think. The magazine quotes the study’s lead author, Dr.
Dariush Mozaffarian, a cardiologist and instructor of medicine at
Brigham and Women’s Hospital, in Boston, explaining that the heart
resets its electrical activity after every beat. "When there is heart disease," he says, "the resetting can be delayed.
That is dangerous."
Forbes reports that while the new study found that the more fish consumed, the
greater the benefits, most gains were achieved with just one or two
meals of fish a week. It had to be the right kind of fish, and prepared the right
way. No effect on the heart’s electrical activity was seen with
fried fish, such as fish burgers or fish sticks.