Fish Oil and Heart Health

BRESCIA, ITALY. Heart failure, also known as congestive heart failure, is generally defined as the inability of the heart to supply sufficient blood flow to meet the needs of the body. Common causes of heart failure include heart attack(s), ischemic heart disease (coronary artery disease), hypertension, valvular heart disease, and cardiomyopathy (enlarged or weakened heart muscle). Heart failure is most often associated with reduced blood flow to the heart (ischemic), but can also be due to an enlarged and weakened left ventricle (non-ischemic dilated cardiomyopathy). A landmark study (GISSI-HF) reported in 2008 found evidence that supplementation with 1 gram/day of fish oil significantly reduced mortality and hospitalization in patients with heart failure (either ischemic or non-ischemic).

A group of researchers from the University of Brescia report that fish oil supplementation is highly effective in reversing non-ischemic dilated cardiomyopathy (NICM). Their clinical trial involved 133 patients with chronic NICM and left ventricular systolic dysfunction (defined as a left ventricular ejection fraction of less than 45%) who were enrolled in 2007-2008. The average age of the patients was 63 years and 10% were women. Average time since diagnosis was 4 years and the average NYHA functional class was 1.85. The New York Heart Association (NYHA) classification defines severity of heart failure as class I to IV with class IV being the most severe. All patients were on a drug regimen consisting of a beta-blocker, an ACE inhibitor or angiotensin receptor blocker, and furosemide (a diuretic).

At the start of the trial, participants were randomly assigned to a placebo group or a fish oil group. The placebo group received a 1-gram capsule of olive oil a day for the duration of the trial. The fish oil group received 5 capsules a day for the first month (providing 1625 mg/day of EPA (eicosapentaenoic acid) and 2700 mg/day of DHA (docosahexaenoic acid) in the form of ethyl esters) and then 2 capsules a day for the remaining 11 months of the trial (providing 650 mg/day of EPA and 1080 mg/day of DHA).

At the end of the 12-month trial, the researchers observed the following statistically significant differences between the two groups.

Fish oil Group
Placebo Group
Left ventricular ejection fraction
10.4% increase
5.0% decrease
Exercise capacity peak (VO2)
6.2% increase
4.9% decrease
Exercise duration
7.7% increase
5.7% decrease
Worsening of NYHA class
Hospitalization rate

At the conclusion of the trial, a significant decrease in inflammatory biomarkers was also noticed in the fish oil group, whereas the level of inflammatory biomarkers had risen significantly in the placebo group. Furthermore, whereas 24% of the placebo group required an increase in their daily furosemide dosage, 39% of the fish oil group were able to reduce their dosage. Overall, among study participants randomized to fish oil, 27% showed improvement in myocardial function, whereas 30% of the placebo group showed a decline from their baseline condition.

The researchers conclude that fish oil supplementation improves left ventricular systolic function and heart function in general, and may reduce hospitalization for heart failure-related complications.
Nodari, S, et al. Effects of n-3 polyunsaturated fatty acids on left ventricular function and functional capacity in patients with dilated cardiomyopathy. Journal of the American College of Cardiology, Vol. 57, No. 7, February 15, 2011, pp. 870-79

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