In a randomized, placebo-controlled trial, the effects of treatment with
fish oil (
eicosapentaenoic acid, 1.08 g/day) and mustard oil (
alpha-linolenic acid, 2.9 g/day) were compared for 1 year in the management of 122 patients (
fish oil, group A), 120 patients (mustard oil, group B), and 118 patients (placebo, group C) with suspected acute
myocardial infarction (AMI). Treatments were administered about (mean) 18 hours after the symptoms of AMI in all three groups. The extent of
cardiac disease, rise in cardiac
enzymes, and
lipid peroxides were comparable among the groups at entry into the study. After 1 year total
cardiac events were significantly less in the
fish oil and mustard oil groups compared with the placebo group (24.5% and 28% vs. 34.7%, p < 0.01). Nonfatal
infarctions were also significantly less in the
fish oil and mustard oil groups compared with the placebo group (13.0% and 15.0% vs. 25.4%, p < 0.05). Total cardiac deaths showed no significant reduction in the mustard oil group; however, the
fish oil group had significantly less cardiac deaths compared with the placebo group (11.4% vs. 22.0%, p < 0.05). Apart from the decrease in the
cardiac event rate, the
fish oil and mustard oil groups also showed a significant reduction in total
cardiac arrhythmias, left ventricular enlargement, and
angina pectoris compared with the placebo group. Reductions in blood
lipoproteins in the two intervention groups were modest and do not appear to be the cause of the benefit in the two groups. Diene conjugates showed a significant reduction in the
fish oil and mustard oil groups, indicating that a part of the benefit may be caused by the reduction in oxidative stress. The findings of this study suggest that
fish oil and mustard oil, possibly due to the presence of
n-3 fatty acids, may provide rapid protective effects in patients with AMI. However, a large study is necessary to confirm this suggestion.