Fish oils are a rich source of long-chain polyunsaturated fatty acids, better known as omega-3 fatty acids. The two most studied omega-3 fatty acids are the 20-carbon eicosapentaenoic acid (EPA) and the 22-carbon docosahexaenoic acid (DHA).
Due to current dietary habits, the median intake of omega-3 fatty acids EPA and DHA for Americans is approximately 128 mg/day, well below any level of benefit. National Health and Nutrition Examination Survey (NHANES) data reveals that fish intake is approximately three ounces per week and, moreover, from seafood that is not high in omega-3 fatty acids. A recent published review concluded that there is extensive evidence from three decades of research that fish oils, or more specifically the omega-3 fatty acids contained in them, are beneficial for everyone. This includes healthy people as a supplement for disease prevention as well as those with heart disease -- including post myocardial infarction (MI) patients and those with heart failure, atherosclerosis, or atrial fibrillation. If you are seeking the potential benefits of fish oils, look for fish oil capsules containing ~600 mg of omega-3's made up of 360 mg of EPA and 240 mg of DHA. Take 1 capsule daily if not consuming 2 to 4 servings per week of fatty fish unless a qualified health professional advises more for a specific condition.