Today, heart failure accounts for the majority of hospitalizations in people 65 and older. Yet evidence continues to grow, pointing to a simple way to reduce the risk of cardiac disease: eating fatty fish just once a week.

In one of the largest studies done to evaluate the association between fatty fish and congestive heart failure, researchers from Beth Israel Deaconess Medical Center (BIDMC) followed 39,367 Swedish men from 1998 to 2004. The men were between the ages of 45 and 79. Using Swedish inpatient hospital registers and cause-of-death registers, the BIDMC researchers recorded details about their diets, as well as tracked their outcomes. During the course of the six-year study, 597 men in the study, none of whom had a previous history of heart disease or diabetes, developed heart failure, and 34 died.

The men were divided into five groups based on the amount of fatty fish they consumed, from those who ate little or no fish to those who ate three or more servings per week. The study determined that participants who reported including fish once in their weekly diets were 12 percent less likely to develop heart failure than their non-fishing eating counterparts. Moreover, those men who had an intake of 0.36 grams of marine omega-3 fatty acids, typically found in cod liver and other fish oils, were 33 percent less likely to develop heart failure. Interestingly, first author Emily Levitan, Ph.D., a research fellow in the Cardiovascular Epidemiology Research Center at BIDMC, noted that the groups that ate either two, three or more servings a week had nearly the same heart failure risk as the men who ate no fish at all. "The higher rates of heart failure in men who consumed the most fatty fish or marine omega-3 fatty acids compared with the men who had moderate consumption may be due to chance," explains Levitan, who adds that "the men who ate more fish may already be in poor health and may be trying to improve their health through fish consumption."

Their findings contribute to a growing body of evidence that suggests health benefits associated with eating such fatty fish as herring, mackerel, salmon, whitefish and char. As Dr. Levitan notes, "Previous research has demonstrated that fatty fish and omega-3 fatty acids help to combat risk factors for a range of heart-related conditions, such as lowering triglycerides, blood pressure, heart rate and heart rate variability. Collectively, this may explain the association with the reduced risk of heart failure found in our study." Moreover, she says, "It reinforces the current recommendations for moderate consumption of fatty fish."

Heart failure is a life-threatening condition that occurs when the heart is unable to continue pumping enough blood to meet the body's requirements. Common causes include high blood pressure, coronary artery disease and diabetes. Symptoms range from fatigue and weakness to rapid or irregular heartbeat and persistent coughing or wheezing.