What Are Fish Oils? What Are Omega-3 Fats?Main Category: Nutrition / Diet
Article Date: 14 Sep 2012
Fish oils come from fatty fish, also known as oily fish, specifically the tissue of fatty fish, such as trout, mackerel, tuna, herring, sardines, and salmon.
Fish oils are of interest to nutritionists and health care professionals because of two main ingredients: DHA (docosahexaenoic acid), and EPA (eicosapentaenoic acid) - both types of Omega-3 fatty acids.
The fillets of oily fish contain up to 30% oil; this figure may vary. White fish, on the other hand, only contain high concentrations of oil in the liver, and have much less oil. Apart from omega-3 fatty acids, oily fish are also good sources of vitamins A and D. Whitefish also contain these nutrients, but at much lower concentrations.
Health experts commonly tell people that oily fish have more health benefits than white fish. However, their recommendations have never been compellingly proven scientifically in large population studies.
Many health authorities around the world advice people to consume either plenty of oily fish or to take supplements, because of their supposed health benefits. Studies over the last ten years have produced mixed results regarding the benefits of the dietary intake of fish oils.
How true are the fish oil health claims?Over the last ten years, there have been dozens of studies on fish oils and omega-3 oils. Some have backed up these claims, while others have not.
Fish oils are said to have several health benefits if they are included in a human diet, including:
Do fish oil supplements offer heart benefits?Experts and members of the general public have believed that a high consumption of omega-3 oils has heart benefits. However, studies have produced mixed results.
A 2011 study, on the other hand, 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 attacks compared to those not on fish oils.
Are low Japanese heart disease rates linked to high fish oil consumption?Researchers from the University of Pittsburgh Graduate School of Public Health set out to determine why the incidence of heart disease in Japan is much lower than in the USA, Canada, Western Europe and Australasia.
They reported in the Journal of the American College of Cardiology in April 2008 that omega-3-rich fish consumption in Japan is much higher than in other developed nations. The authors believe that the greater consumption of fish oils in Japan is a main contributor to its relatively lower heart disease rates.
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 US population. Atherosclerosis is a major risk factor for heart disease.
Study lead author Akira Sekikawa, M.D., Ph.D.,
"Our study suggests that very high levels of omega-3 fatty acids have strong properties that may help prevent the buildup of cholesterol in the arteries. Increasing fish intake to two times a week for healthy people is currently recommended in the U.S. Our study shows much higher intake of fish observed in the Japanese may have strong anti-atherogenic effect."
Japanese adult males consume approximately 3.75 ounces (100 grams) of fish each day. Their US counterparts eat fish no more than twice a week.
North American diet deficient in omega-3 oilsAmericans and Canadians eat too much meat and not enough fish, researchers from the University of British Columbia reported in the American Journal of Nutrition in 2008.
The authors added that the North American lifestyle means people are not getting adequate amounts of dietary omega-3 fatty acids. They emphasized that pregnant and breastfeeding women particularly need to make sure they consume plenty of omega-3 oils.
They found that North American women's babies did not do as well on eye tests if they were deficient in omega-3 fatty acids while they were pregnant.
Which foods are rich in omega-3 fatty acidsThe following foods are rich in omega-3 fatty acids:
Spinach is rich in omega-3.
How can vegans make sure their omega-3 fatty acid intake is sufficient?Without proper planning, vegans and vegetarians have a much higher risk of being omega-3 deficient than humans who eat animal-sourced proteins.
A vegan consumes no animal-sourced protein at all, not even honey, while a vegetarian may include eggs and dairy in their diet. The risk of not consuming enough omega-3 fatty acids is higher for vegans than vegetarians if they do not plan their diets well.
According to veganhealth.org, vegans may obtain their necessary omega-3 supplies by either taking supplements or adding plant-sourced omega-3 foods to their diet. Several foods sold in shops and supermarkets have omega oils added to them, such as many margarines and spreads. See the list of foods with omega oils above and select the plant-based ones.
Flaxseed and rapeseed oils are very high in omega-3 fatty acids, while soybean and walnut oils are high in omega-6 fatty acids. However, you should remember not to cook these at a high temperature.
Written by Christian Nordqvist
Original article date: 24 March 2006. Article updated: 31st October 2012
Copyright: MediLexicon International Ltd
Original article posted on Medical News Today.
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