original article posted at http://my.webmd.com/content/Article/90/100878.htm
Baked or Broiled Fish Lowers Risk of Irregular Heartbeat Among Elderly
July 19, 2004 -- Baked or broiled fish beats fried when it comes to lowering the risk of at least one common heart problem, a new study shows.
Researchers found elderly people who regularly ate baked or broiled fish, such as tuna, had a much lower risk of suffering a potentially deadly irregular heartbeat. But eating fried fish or fish sandwiches (fish burgers) failed to provide the same heart healthy benefits.
It's one of the first studies to look at whether eating fish affects the risk of suffering an irregular heartbeat, a common condition known as atrial fibrillation.
Atrial fibrillation affects nearly 2 million Americans and is a common cause of stroke. The condition occurs when the heart's upper chambers quiver rather than pump regularly and effectively. This increases the risk of clots forming within the heart, which can then lead to a stroke if the clot goes from the heart to the brain.
In the study, researchers looked at the diets of a group of more than 4,000 people over age 65 who participated in the Cardiovascular Health Study from 1989-1990. After 12 years of follow up, nearly 1,000 cases of atrial fibrillation were reported.
Researchers found that people who frequently ate tuna fish or other fish that was broiled or baked had a lower risk of atrial fibrillation.
For example, people who ate baked or broiled fish one to four times per week had a 28% lower risk of atrial fibrillation, and those who ate five or more servings per week had a 31% lower risk compared with those who ate these types of fish less than once a month.
"The results suggest that regular intake of tuna or other broiled or baked fish may be a simple and important deterrent to AF among older men and women," said researcher Dariush Mozaffarian, MD, instructor of medicine at Harvard Medical School in Boston, in a news release.
Researchers say an earlier study on a subgroup of the people involved in this study showed that eating tuna or other baked and broiled fish was linked to higher levels of omega-3 fatty acids in the blood. Eating this type of fat from fish appears to lower the risk of abnormal and sometimes fatal heartbeat irregularities. But eating fried fish or fish sandwiches was not associated with higher omega-3 fatty acid levels and may increase the levels of trans fat.
Omega-3 fatty acids are found in fatty fish, such as tuna, salmon, mackerel, and sardines, and have been shown to reduce the risk of heart disease.
Finally, the study showed that eating fried fish or fish sandwiches was not associated with any reduction in atrial fibrillation risk. Researchers say this may be related to the fact that most fried fish or fish sandwiches eaten in the U.S. are made with lean (white) fish such as cod or pollock, which does not contain significant levels of omega-3 fatty acids.
SOURCES: Mozaffarian, D. Circulation: Journal of the American Heart Association, July 20, 2004; vol 110: pp 368-373. News release, American Heart Association.
Another article: Eat Fish, Good for Your Brain