Some of the benefits of taking fish oil are healthier blood pressure levels, lower tryglyceride levels and an overall healthier cardiovascular system, according to the National Institutes of Health's MedlinePlus. By consuming fish oil on a daily basis, a person may also be less likely to suffer from or develop bipolar disorder, macular degeneration, asthma, endometrial cancer, strokes and rheumatoid arthritis.
Fish oil is mostly commonly extracted from fish that are high in healthy omega-3 fatty acids, according to MedlinePlus. Some fish that are very high in omega-3 acids are trout, sturgeon, herring, bluefish, menhaden and mackerel. Supplements that include fish oil and other minerals and nutrients are primarily manufactured from cod liver, halibut, seal blubber, whale blubber or tuna.