Fish Reduces Sudden Heart Death, Study Says
Two new studies show people who eat substantial amounts of oily fish are greatly protected from sudden, unexpected death, a common condition usually caused by severely abnormal heart rhythms.
The studies--which both draw their conclusions from long-term observation of tens of thousands of people--greatly bolster the evidence that eating fish regularly can have major health benefits. While most of earlier studies focused on men, one of the new studies demonstrates fish’s benefit in women.
The benefit for men and women appears to come mostly from fish’s effect on the risk of sudden cardiac death, although in the study involving women fish protected against nonfatal heart attacks too.
Each year, about 220,000 Americans experience sudden death, collapsing and dying within an hour, often before they get to a hospital. In most cases, an abnormal heart rhythm arising from existing heart disease is believed to be the cause.
“Prevention is really the only way to impact the rate and mortality from sudden death,” said Christine Albert, a cardiologist at Brigham and Women’s Hospital in Boston, who headed one of the studies. “One way you could do it in a population that’s healthy is through diet and lifestyle.”
In one study, which appears in today’s Journal of the American Medical Assn., a team led by JoAnn Manson, also a physician at Brigham and Women’s Hospital, studied the experience of 85,000 women nurses as part of the Nurses’ Health Study, which began in 1976.
The researchers found the more frequently a woman ate fish, the less likely she was to suffer a heart attack or die of any cardiac cause. Specifically, those who ate fish once a week had a 30% lower risk of heart attack or death compared to those who never ate fish.
In the other study, to be published in Thursday’s New England Journal of Medicine, Albert and her colleagues looked at the experience of 22,000 male doctors who enrolled in the Physicians’ Health Study in 1982. They were all free of heart disease at the time, and 15,000 also volunteered a blood sample.
In 17 years, 94 of the men who had given blood samples and who hadn’t subsequently been diagnosed with heart disease died suddenly. The researchers chose about 180 surviving members of the study and compared them to those victims. In particular, they compared the bloodstream concentrations of substances called n-3 fatty acids, found primarily in fish oils.
On average, the men who died had lower amounts of n-3 fatty acids than the ones who hadn’t died suddenly. When researchers divided all the men into four groups based on the concentration of n-3 fatty acids in the blood, the men in the highest quarter had only one-fifth the risk of sudden death as those in the lowest quarter.
