Aug. 12, 2003 -- Fatty fish can help keep your heart rate low,
Aug. 12, 2003 -- Fatty fish can help keep your heart rate low, helping to prevent sudden heart death.
That's the message from a new study from France.
In the past decade, we've learned much about the heart-protective effects of eating fish, writes lead researcher Jean Dallongeville, MD, PhD, an epidemiologist with the Institut Pasteur de Lille in France. His paper appears in the latest issue of Circulation: Journal of the American Heart Association.
Studies have linked fish with fewer deaths from heart attack. The omega-3 fatty acids in fatty fish -- such as salmon, mackerel, and herring -- are considered the secret heart-healthy ingredient.
However, it's not been clear exactly how these fatty acids worked to reduce heart problems.
Tracking Fish Eaters
This current study involves more than 9,700 men -- all between 50 and 59 years old -- who had no signs of heart disease. Researchers kept track of them from 1991 to 1993, documenting their heart rate, blood pressure, cholesterol, and other heart disease risk factors. They asked the men about exercise, tobacco and alcohol intake, and their diet, including how often they ate fish -- but did not differentiate between different types of fish.
A subgroup of 407 men also got blood tests to assess fatty acid levels.
Fish eaters had the lowest heart rates. It's important information because even small reductions in heart rate can make a difference in sudden heart death, Dallongeville writes.
Researchers found that men who ate fish less than once a week had an average heart beat of 67.5 beats per minute compared with 65.5 beats per minute for men who at fish more than twice a week.
Likely, it's because fatty acids stabilize electrical activity of heart cells, thereby lowering heart rate, he explains. Fatty acids may also positively affect pumping action and blood pressure, which also factor into reduced heart rate.
Evidence was also in their blood. Fish eaters had lots of heart-protective fatty acids in their blood. They also had lower triglycerides and lower blood pressure -- and their HDL "good" cholesterol levels were higher. But fish didn't seem to affect "bad" LDL or total cholesterol levels.
Generally, fish eaters have different exercise and nutritional habits -- such as drinking alcohol -- that may play into better heart rates, Dallongeville writes. But in his study, fish followed by physical activity were key to lowering sudden death from heart disease.
SOURCE: Circulation: Journal of the American Heart Association, Aug. 19, 2003.
