Fish oil is oil derived from the network of oily fish. Fish oil contains eicosapentaenoic acid omega-3 fatty acids (EPA) and docosahexaenoic acid (DHA), a specific eicosanoid precursor known to reduce inflammation in the body, and has other health benefits, such as treating hypertriglyceridemia, although claims to prevent heart attacks or strokes are not supported. Fish oil and omega-3 fatty acids have been studied in many other conditions, such as clinical depression, anxiety, cancer, and macular degeneration, but the benefits under these conditions have not been verified.
Fish used as a source actually do not produce omega-3 fatty acids, but instead accumulate them by eating fish of microalgae or prey that have accumulated omega-3 fatty acids.
Fatty predator fish such as shark, swordfish, tilefish, and albacore tuna may be high in omega-3 fatty acids, but because of its position at the top of the food chain, this species can also collect toxic substances through biomagnification. For this reason, the US Environmental Protection Agency recommends limiting consumption (especially for women of child-bearing age) of certain fish species (predators) (eg albacore tuna, shark, king mackerel, tilefish and swordfish) due to high levels of toxic contaminants. Mercury. Dioxins, PCBs, and chlordane are also present. Fish oil is used as a component in aquaculture feed. More than 50 percent of the world's fish oils used in aquaculture feeds are fed to cultivated salmon.
Sea and freshwater fish oils vary in arachidonic acid, EPA and DHA. Various species range from lean to fat and their oil content in tissues has been shown to vary from 0.7% to 15.5%. They also differ in their effects on lipid organs. Research has revealed that there is no association between total fish intake or estimated intake of omega-3 fatty acids from all fish, and serum omega-3 fatty acid concentrations. Only intake of fatty fish, especially salmon, and estimated EPA DHA intake from fatty fish have been observed significantly associated with elevated serum EPA DHA.
Video Fish oil
Usage
Often marketed and sold for consumption as part of diet or dietary supplements in contemporary societies, fish oil has also found a role in external use, as an emollient or as a general ointment or in body art, or for alleged insulation against cold.
Maps Fish oil
Nutrient details
The most widely available food sources of EPA and DHA are cold-watered fish, such as salmon, herring, mackerel, anchovies, and sardines. The oil of this fish has a profile of about seven times as much omega-3 oil as omega-6 oil. Other oily fish, like tuna, also contain omega-3s in slightly lower amounts. Although fish are a source of omega-3 oils, fish do not synthesize them; they get it from algae (especially microalgae) or plankton in their diet.
For comparison, note the omega-3 levels in some common non-fish foods:
Health effects
Various recommendations
In a 2009 letter about a delayed revision to the Dietary Guidelines for America, the American Heart Association recommends 250-500 mg/day of EPA and DHA. The guidelines are revised again for 2015-2020; including is a recommendation that adults consume at least eight ounces of various types of fish per week, equalizing at least 250 mg/day of EPA DHA. The Food and Drug Administration recommends not to exceed 3 grams per day of EPA DHA from all sources, with no more than 2 grams per day of dietary supplements.
Prostate cancer
The effect of fish oil consumption on prostate cancer is controversial, as one study showed a reduced risk with higher blood DPA levels, while others reported an increased risk of more aggressive prostate cancer with higher blood EPA and DHA levels. Some evidence suggests a link between high levels of omega-3 fatty acids and an increased risk of prostate cancer.
Cardiovascular
Studies of fish oil supplements fail to support claims to prevent heart attacks or strokes. Previously, in 2007, the American Heart Association had recommended the consumption of 1 gram of fish oil daily, preferably by eating fish, for patients with coronary artery disease, but warning pregnant and lactating women to avoid eating fish with high potential for mercury contaminants including mackerel, shark, and swordfish. (The optimal dose associated with weight.)
The US National Institutes of Health lists three conditions in which fish oil and other omega-3 sources are highly recommended: hypertriglyceridemia (high triglyceride levels), preventing secondary cardiovascular disease, and hypertension (high blood pressure). Then a list of 27 other conditions is lacking in evidence. It also lists possible safety concerns: "A 3 gram intake per day or more of omega-3 fatty acids may increase the risk of bleeding, although there is little evidence of significant bleeding risk at lower doses • Very large intake of fish oil/omega. 3 fatty acids may increase the risk of hemorrhagic stroke (bleeding). "
There is also some evidence that fish oil may have beneficial effects on certain abnormal heart rhythms. However, the 2012 meta-analysis found no significant benefits.
A 2008 meta-study by the Canadian Medical Association Journal found that fish oil supplementation did not show a preventive benefit for heart patients with ventricular arrhythmias. A 2012 meta-analysis published in the Journal of the American Medical Association, which included 20 studies and 68,680 patients, found that Omega-3 Fatty Acid supplementation did not reduce the chances of death, heart death, heart attack or stroke.
Hypertension
There are several tests in humans that conclude that consuming omega-3 fatty acids slightly reduces blood pressure (DHA can be more effective than EPA). It is important to note that since omega-3 fatty acids can increase the risk of bleeding, qualified health care providers should be consulted before supplementing with fish oil.
Mental health
A systematic review of Cochrane 2008 found that limited data is available. In one eligible study, omega-3 is an effective adjunctive therapy for depressive symptoms but not a mania in bipolar disorder. The authors found an "acute need" for randomized controlled trials.
A 2009 metastudi found that patients taking omega-3 supplements with EPA ratios: higher DHA experienced fewer symptoms of depression. Studies provide evidence that EPA may be more efficacious than DHA in treating depression. However, the metastudi concludes that due to the limitations identified from larger, larger, randomized trials are needed to confirm these findings.
In the 2011 PubMed article meta-analysis of fish oil and depression from 1965 to 2010, the researchers found that "virtually all treatment efficacy observed in the published literature may be due to publication bias."
A 2014 meta-analysis of eleven trials was conducted in patients with DSM diagnoses defined by major depressive disorder (MDD) and eight trials with patients with depressive symptomatology but no MDD diagnosis showed significant clinical benefit from the treatment of omega-3 PUFA compared to placebo. The study concluded that: "The use of omega-3 PUFAs is effective in patients with MDD diagnosis and in depressed patients without MDD diagnosis."
Alzheimer's Disease
A Cochrane meta-analysis published in June 2012 found no significant protective effect for cognitive decline for those aged 60 years and over and who started taking fatty acids after this age. A study author told Time , "Our analysis shows that there is currently no evidence that omega-3 fatty acid supplements provide benefits for memory or concentration at a later date".
Psoriasis
Foods added with cod liver oil have shown beneficial effects on psoriasis.
Pregnancy
Several studies reported better psychomotor development at age 30 months in infants whose mothers received fish oil supplements during the first four months of lactation. In addition, five-year-old children whose mothers received simple algae docosahexaenoic acid supplementation for the first 4 months of breast-feeding performed better on continuous attention tests. This suggests that docosahexaenoic acid intake during early infancy provides long-term benefits on certain aspects of neural development.
In addition, the provision of fish oil during pregnancy can reduce the infant's sensitivity to common food allergens and reduce the prevalence and severity of certain skin diseases in the first year of life. This effect can persist until adolescence with decreased prevalence and/or severity of eczema, fever and asthma.
Crohn's Disease
The 2014 Cochrane Review found that, based on two large studies, fish oil supplements appear to be ineffective for maintenance of remissions in Crohn's disease.
Additional quality and concerns
Fish oil is a commonly used food supplement, with sales in the US alone reaching $ 976 million in 2009. Quality issues have been identified in periodic tests by independent researchers of marketed supplements containing fish oil and other marine oils. These problems include contamination, inaccurate levels of EPA and DHA levels, decomposition and formulation problems.
Contamination
Fish can accumulate toxins such as mercury, dioxin, and polychlorinated biphenyls (PCBs), and damaged fish oils can produce peroxides. There appears to be little risk of contamination by microorganisms, proteins, lysophospholipids, cholesterol, and trans-fats.
Dioxin and PCB
Dioxins and PCBs may be carcinogenic at low exposure levels over time. These substances are identified and measured in one of two categories, dioxin-like PCBs and total PCBs. While the US FDA has not set limits for PCBs in supplements, the Global Organization for EPA and DHA (GOED) has established guidelines that allow no more than 3 picogram PCB dioxins such as per gram of fish oil. In 2012, samples from 35 fish oil supplements were tested for PCBs. The number of PCB traces found in all samples, and two samples exceeded the GOED limit. Although trace amounts of PCBs contribute to overall PCB exposure, Consumerlab.com claims the amounts reported by the test ordered on fish oil supplements are well below those found in one serving of regular food.
Decay
Peroxides can be produced when fish oil is damaging. A study conducted by the Norwegian government concluded that there would be some health concerns associated with regular consumption of fish oil/oxidized (rancid) fish, especially in the digestive tract, but there is not enough data to determine the risks. The amount of decay and contamination in the supplement depends on the raw material and the extraction, purification, concentration, encapsulation, storage and transportation processes. ConsumerLab.com reported in its review that it found decay in the test reports it ordered on some fish oil supplement products.
Content EPA and DHA
According to independent laboratory tests, EPA and DHA concentrations in supplements can vary between 8 and 80% of fish oil content. The concentration depends on the source of omega-3, how the oil is processed, and the amount of other ingredients included in the supplement. The 2012 report claims 4 of the 35 fish oil supplements covered contain fewer EPA or DHA than those claimed on the label, and 3 out of 35 contain more A ConsumerLab.com publications in 2010 claiming 3 of 24 fish oil supplements that contain more less EPA and/or DHA than claimed on the label. However, EPA and DHA bioavailability of both fish oil capsules and emulsions has been shown to be high.
Formulation
Fish oil supplements are available in liquid or capsule form. Some enteric-coated capsules pass through the stomach before being dissolved in the small intestine, thus helping to prevent indigestion and "burping fish." Poorly coated enteric products produced have the potential to release material prematurely. ConsumerLab.com, a nonprofit supplement testing company, reported that 1 of 24 affiliated enteric oil fish supplements evaluated prematurely released materials.
Fish oil with recipe
The preparation of fish oils that are available only by prescription undergo the same FDA regulatory requirements as other prescription drugs, with respect to effectiveness and safety.
Dangers
A 2013 review concludes that the potential side effects among older adults who consume fish oil "appear mild-moderate in the worst conditions and may not have clinical significance".
Maximum intake
The FDA recommends that consumers do not exceed more than three grams per day of combined EPA and DHA, with no more than 2 grams of dietary supplements. It is not equal to 3000 mg fish oil. 1000 mg pills usually have only 300 mg of omega-3; 10 such pills would be equal to 3000 mg of omega-3. According to the European Food Safety Authority (EFSA) Panel on Diet Products, Nutrition and Allergies, the combined 5 gram EPA and DHA supplements do not pose any safety concerns for adults. Dyerberg studied Inuit Greenland healthy and found an average intake of 5.7 grams of omega-3 EPA per day; among other effects these people have prolonged bleeding time, that is, slower blood clots.
Vitamins
Liver and liver products (such as cod liver oil) fish and many animals (such as seals and whales) contain omega-3, but also the active form of vitamin A. At high levels, this vitamin form can be harmful. (Hypervitaminosis A).
Poisonous pollutants
Oily fish consumers should be aware of potential heavy metals and fat-soluble pollutants such as PCBs and dioxins, which are known to accumulate food chains. After extensive review, researchers from the Harvard Public Health School at the Journal of the American Medical Association (2006) report that the benefits of fish intake are generally far greater than the potential risks.
Fish oil supplements were under scrutiny in 2006, when the UK Food Standards Agency and the Irish Food Safety Authority reported PCB levels that exceeded the European maximum limit in some brands of fish oil, which required temporary withdrawal of these brands. To address concerns over contaminated fish oil supplements, the International Fish Oil Standard Program (IFOS), a third party testing and accreditation program for fish oil products, is manufactured by Nutrasource Diagnostics Inc. in Guelph, Ontario, Canada.
The March 2010 lawsuit filed by California environmental groups claimed that eight brands of fish oil supplements contain excessive levels of PCBs, including CVS/pharmaceuticals, Nature Made, Rite Aid, GNC, Solgar, Twinlab, Now Health, Omega Protein and Pharmavite. The majority of these products are fish liver oil or shark liver. Those who participated in the lawsuit claimed that because the liver is the major filtering and detoxifying organ, PCB content may be higher in liver-based oils than in fish oils produced from whole fish processing.
A analysis based on data from the Norwegian Women and Cancer Study (NOWAC) regarding the dangers of persistent organic pollutants (POPs) in cods came to the conclusion that "in Norwegian women, liver consumption is not associated with increased cancer, risk in the breast, uterus, or colon, in contrast, a decreased risk for total cancer is found. "
A report by Harvard Medical School studied five popular brands of fish oil, including Nordic Ultimate, Kirkland, and CVS. They found that the brands "have a negligible amount of mercury, indicating that mercury will be eliminated during the manufacture of refined fish oil or that the fish source used in commercial preparations is relatively mercury-free."
Microalgae oil is a vegetarian alternative to fish oil. Supplements produced from microalgae oils provide a balance of omega-3 fatty acids similar to fish oil, with a lower risk of pollutant exposure.
See also
Note
References
- FAO (1986) FAO Fishery Technical Paper FAO (1986) FAO Fishery Technical Paper 142. ISBNÃ, 92-5-102464-2.
External links
- International Fish Oil Standard - An organization concerned with the quality of omega-3 products related to international standards established by the World Health Organization and the Council for Responsible Nutrition for purity and concentration.
- Joyce A. Nettleton, ed. "Bulletin PUFA" . Retrieved February 20 2006 . CS1 maint: Additional text: author list (link) Two bulletins, both quarterly, review recent publications in essential fatty acids. One is written for researchers, the second is for consumers. Industry sponsor, academic contributor.
- Omega-3 Fatty Acids American Cancer Society . Updated January 11, 2008.
Source of the article : Wikipedia
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