Benefits of Fish in Heart Failure Questioned
Several years ago, the results of a 12-year study found that eating fish was associated with a reduced incidence of heart failure. That was in 2005. Today, results of a new study which also followed the participants for nearly 12 years found that fish consumption does not play a major role in preventing heart failure.
Contradictory or questionable study results are certainly nothing new and provide opportunities for healthcare consumers and experts to reexamine the research and the methods used. Such scrutiny is especially important when the health condition being examined is both life-threatening and pervasive. Heart failure, a condition characterized by an inability of the heart to pump enough blood through the body, affects about 5 million Americans, according to the Heart, Lung and Blood Institute. It contributes to about 300,000 deaths per year.
In the current study, the results of which were published in the October issue of the European Journal of Heart Failure, the investigators evaluated data from a group of 5,299 men and women older than 55 years who lived in a suburb or Rotterdam. All were free of heart failure when they entered the study in 1990. During the 11.4 years of follow-up, 669 participants developed heart failure. The diet of each participant had been assessed at baseline, and everyone was asked specifically to indicate the amount, type, and frequency of fish consumed.
The cardiovascular benefits associated with fish are related to the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that they contain. Both EPA and DHA have demonstrated anti-inflammatory, anti-arrhythmic, and anti-hypertensive properties, as well as an ability to reduce triglyceride levels.
In the latest study, the researchers found no correlation between the amount of fish consumed and heart failure incidence. This lack of effect remained even when comparing high daily fish consumption (more than 20 grams) with no fish intake.
In the earlier study, which was published in the Journal of the American College of Cardiology, 4,738 participants ages 65 year or older were followed for 12 years. When compared with fish consumption of less than one time per month, those who ate fish 1 to 2 times per week had a 20 percent reduced risk of heart failure; 3 to 4 times weekly, a 31 percent reduce risk; and a 37 percent reduce risk was seen when comparing the highest intake with the lowest.
Although the results of the newest study did not show fish to help prevent heart failure, the authors noted that they agree with the current general recommendation of two weekly servings of fish for the prevention of cardiovascular disease. Fish is an excellent source of omega-3 fatty acids, and a good source of vitamin D, selenium, and protein. They also pointed out that other research has been consistent in showing omega-3 fatty acids to be protective against coronary heart disease.
Dijkstra et al. European Journal of Heart Failure 2009; 11(10): 922 DOI: 10.1093/eurjhf/hfp126
Heart, Lung and Blood Institute
Mozaffarian D et al. Journal of the American College of Cardiology 2005; 45: 2015