Eicosapentaenoic acid and docosahexaenoic acid, or EPA and DHA, are omega-3 fatty acids found in oily fish, such as salmon, halibut, mackerel and tuna. Fish oil is used to treat high triglycerides, prevent heart disease and lower high blood pressure. The American Heart Association recommends 1 gram of EPA + DHA daily from fish oil if you have existing heart disease, and 500 milligrams daily to prevent the disease. The ratio of EPA to DHA in fish oil varies.
EPA to DHA Ratios
A common ratio is 180 milligrams of EPA to 120 milligrams of DHA, according to a 2004 article published in the "Cleveland Clinic Journal of Medicine." The article reports that ratios of 2:1 or 1:2 EPA to DHA may be equally beneficial, since both compounds seem to work together. The amounts of EPA and DHA in fish oil are not regulated, so it may be difficult to determine if you are actually getting the levels recommended by the American Heart Association.