Fish oils come from fatty or oily fish, for example, trout, mackerel, tuna, herring, sardines, and salmon. They include omega 3 fatty acids and essential vitamins A and D. They cannot be manufactured in the body. Therefore, as humans, we need to consume fish and or supplements to benefit our health. Fish-oil and omega-3 supplements are popular because they are considered to have numerous health benefits.
Cod liver oil and fish oil contain high levels of two types of omega-3 fatty acids: DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). Scientists have discovered that EPA and DHA both decrease swelling.
A recent review of clinical studies concluded that taking fish oil supplements improved depressive symptoms in people with depression*, with effects equivalent to those of antidepressant medications.