June 20, 2005 -- Thinking of eating more fish for heart health? You may want to consider the recipe.
Among older adults, eating tuna or other broiled or baked fish, but not fried fish, is associated with less congestive heart failure, according to a study in the Journal of the American College of Cardiology.
This study shows that fried fish, particularly lean (nonfatty or white) fish, is unlikely to provide the same heart-healthy benefits as fatty or oily fish, says researcher Dariush Mozaffarian, MD, MPH, FACC, in a news release.
About Congestive Heart Failure
Congestive heart failure, which occurs when the heart doesn't pump as strong, becomes more common with age. It's the leading cause of hospitalization for people aged 65 and older.
More than 5 million people in the U.S. have congestive heart failure. That number grows by half a million people per year.
At first, none of the more than 4,700 adults aged 65 and older in Mozaffarian's study had congestive heart failure. By the study's end, 955 people had developed congestive heart failure.
The risk of congestive heart failure was lower for people who frequently ate tuna or other broiled or baked fish. That's according to food surveys taken at the study's start.
How much lower was the risk? Compared with those who ate tuna or other broiled or baked fish less than once a month, congestive heart failure risk was:
- 32% lower when such fish were eaten 5 or more times per week
- 31% lower when such fish were eaten 3 or 4 times weekly
- 20% lower when such fish were eaten once or twice weekly.
Lower Risk Seen With Omega-3 Fats
Fish richest in heart-healthy omega-3 fatty acids were tied to a 37% lower risk of congestive heart failure than fish with the least amount of omega-3 fatty acids.
The food survey didn't name specific types of fish, apart from tuna. In the news release, Mozaffarian says he believes that salmon accounted for a lot of the "other broiled or baked fish."
Fish rich in omega-3 fatty acids include salmon, tuna, and herring. Last September, the FDA decided to allow foods and supplements containing the omega-3 fatty acids found in fish -- DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) -- to bear labels saying that eating the product may help reduce the risk of heart disease.
The U.S. government advises pregnant women and young children to limit eating of some fish due to contaminants such as mercury, says Mozaffarian.
No Benefit Seen From Fried Fish
Fried fish was tied to a higher risk of congestive heart failure. That could be partly due to other unfavorable risk factors seen in people who frequently ate fried fish, the study notes.
The study doesn't sound any alarms about eating fried fish. Doing so would be premature, say the researchers. Still, they say such fish meals aren't likely to cut congestive heart failure risk.
In addition, fried fish is often high in unhealthy fats. And while frying doesn't break down omega-3 fats, it could add unhealthy hydrogenated oils or trans fats, say researchers.
The Final Word?
The findings deserve further study but aren't the final word on fish and congestive heart failure, says Mozaffarian. He works at Harvard Medical School, Harvard School of Public Health, and Boston's Brigham and Women's Hospital.
The study was observational. It didn't assign anyone to eat more fish or change their diets at all. Instead, the results come from food surveys. Those aren't always perfectly accurate. They also don't show dietary changes over time.