Fish oils are extracted fats from fish, a concentrated solution of omega-3 EFAs. It is the best source of omega-3 EFAs. You could add more omega-3 EFAs to your diet in the form of alpha-linolenic acid (ALA). The richest plant sources of ALA are the leaves and seeds of the perilla plants common in North America, Japan, Korea, China and Vietnam.
Green plants and algae also contain ALA as well as linseed oil. However, fats or oil from fish is considered the most important dietary source of omega-3 EFAs because it has concentrated amounts of the ALA derivatives EPA and DHA. These two nutrients are found almost exclusively in seafood.
Eating fish on a regular basis has its own risk as you are can never be sure if the fish you are eating has no toxins on it such as mercury and PCBs. During the manufacture of fish oils, toxins are eliminated. The supplements are meticulously purified to remove heavy metals such as mercury, lead, PCBs and other toxins as well as to reduce the incidence of rancidity and improve the taste and quality of the fish oil.
These makes fish oils as safe and effective food supplement. A 1-gram fish oil capsule contains about 180 mg of EPA and 120 mg of DHA. An intake of three 1-gram capsules would provide 0.9 gram (900 mg) of EPA and DHA. This means it comply the daily dosage recommended by the American Heart Association. However, you should always bear in mind that fish oil supplements are basically dietary supplements, not drugs.
Studies shows that many people are getting too much of the wrong kinds of fats found in animals (saturated fats) and vegetables (polyunsaturated fats), and need the fish oil to “balance” the family of fat nutrients. Intake of the wrong kinds of fats should be lowered to total 20 to 30 percent of daily calorie serving while fats found in the oils of certain fish should be appreciably increased.