Fish oils come from fatty or oily fish. These fish oils are found in the tissue of fish such as trout, mackerel, tuna, herring, sardines, and salmon.
Oily fish can contain up to 30 percent oil. White fish contains high levels of oil in the liver, and have much less oil overall.
Oily fish are good sources of vitamins A and D, along with Omega 3s. Whitefish also does contain these nutrients but at much lower concentrations.
Health experts have often told people that oily fish have greater health benefits than less oily white fish. Some researchers say that is not necessarily the case.
Many health authorities around the globe have recommended that people should consume either plenty of oily fish or to take a fish oil supplement, because of the health benefits associated with fish oil. Some studies in recent years though have produced mixed results about the dietary intake of fish oil
Fish oils and Cod liver oil are often confused – they are different. Fish oils are taken from the tissue of deep sea oily fish such as salmon, tuna or mackerel. Cod liver oil is extracted solely from the livers of cod fish.
Do fish oil supplements offer heart benefits? Does omega-3 benefit heart health?
Many people believe that a high consumption of omega-3 oils can benefit the heart. However, studies have produced mixed results.
Heart benefits discovered in a 2011 study, carried out by researchers at Michigan Technological University, found that fish oil consumption can improve blood flow by reducing triglyceride levels, as well as slowing down the growth rate of atherosclerotic plaques.
Fish oils help patients with stents in their arteries – people with stents in their heart who took two blood-thinning drugs, as well as omega-3 fatty acids, were found to have a lower risk of heart attack compared with those not on fish oils.
Researchers from one United States University set out to determine why the incidence of heart disease in Japan is much lower than in America, Canada, Western Europe, and Australia.
They reported that omega-3-rich fish consumption in Japan is much higher than in other developed nations. The authors believe that this is the main contributor to its relatively low rate of heart disease.
The scientists explained that the difference cannot be explained by genetic factors. Third and fourth generation Japanese-Americans have either the same or higher rates of hardening of the arteries (atherosclerosis) than the rest of the American population.
Researchers have concluded that Americans and Canadians eat far too much meat and not enough fish. They also suggested that the North American lifestyle means people are not getting adequate amounts of dietary omega-3 fatty acids. They emphasized the fact that pregnant and breastfeeding women in particular need to ensure that they consume plenty of omega-3 oils.