The more fish you eat each week, the slower your heart beats, new research suggests. This may help explain why eating fish seems to protect against sudden death--a problem that is often related to a fast heartbeat. The results are based on a study of nearly 10,000 older men without evidence of heart disease. The men were divided into four groups based on weekly fish intake and their heart rate, and risk factors for heart disease were compared. As weekly fish intake increased, heart rates fell, the researchers note. Furthermore, fish consumption remained a predictor of slower heart rates, even after accounting for other factors that can influence heart rate, such as age, smoking status, and physical activity. In agreement with previous studies, fish intake was also associated with a rise in cell levels of omega-3 fatty acids, which are known to have many beneficial effects on the heart. Other effects of fish consumption included a drop in blood pressure, decreased triglyceride levels, and increased HDL ("good") cholesterol levels. The new findings support the idea that fish should be a major dietary component, the authors conclude.