Fish oil: properties, benefits and contraindications
Fish oil is a popular product for those who want to ensure a healthy diet because of its properties and health benefits from the polyunsaturated fatty acids in which it is rich, omega 3.
Besides being used as a raw material for supplements and drugs with fish oil also finds use as an ingredient for the food industry. It is also used within products intended for animal feed to enrich them with essential fatty acids, protect their health and promote their health and reproduction.
Its use as an ingredient in nutraceuticals makes high standards necessary both for its production processes and in terms of the characteristics of the final products. Among these, one of the most sought-after types is Omega-3 purified from fish oil.
According to data released by the European Food Safety Agency (the Efsa), production of this type of product has increased rapidly since 2001, from the initial 20,000 tons to the 85,000 tons recorded in 2009.
In 2010, Efsa found that about 60 percent of this production corresponded to products rich in eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) used as dietary supplements. Another 20% of EPA+DHA-rich products were used in the production of functional foods. Finally, 7% was for animal nutrition, 6% for pharmaceutical use, and the remainder for clinical and pediatric nutrition.
Fish oil: what is it and where does it come from?
Fish oil is an oil rich in polyunsaturated fatty acids obtained from fatty fish such as sardines, mackerel, and salmon.
But how is fish oil produced? Its production process requires two essential steps: theextraction of the oil from the starting material and its purification. The composition and oxidation of the resulting fish oil depend on the composition and oxidation of the starting material.
The latter can be represented by many different species of fish. It can be either material caught specifically for the production of fish oil or fish meal, fish caught while fishing for other species, or residual material from fish industry processing.
Fish oil composition
The composition of "raw" fish oil obtained from extraction processes depends on both these and the starting material. In general, in addition to the long-chain omega-3 fatty acids EPA and DHA within it are a variable (but limited) amount of unsaponifiable compounds, such as hydrocarbons, long-chain alcohols, waxes and ethers that can affect the properties of fish oil.
In some cases, these are beneficial substances (such as tocopherols); in others, however, they are undesirable compounds because they can impart a dark color or unpleasant taste to the fish oil (as can, for example, small residues of protein, water, pigments, free fatty acids, phospholipids, or oxidized fats), or cause foaming, smoking, or precipitates to form during later stages of the production process.
Purification allows all unwanted substances to be removed, but must ensure that the desired components are not damaged. The final product is a source of long-chain omega-3 fatty acids, substances are considered essential for the proper functioning of metabolism. Not surprisingly, we often end up identifying fish oil with omega-3.
Why is fish oil used? What is it used for?
Fish oil is used as a dietary supplement, but not only that. In fact, it is also an ingredient used in the production of cosmetics.
Its use in food comes from the human body's need to take in Omega-3 polyunsaturated fatty acids from outside, which it is unable to synthesize on its own.
In most tissues, the most abundant omega-3 fatty acid is DHA. Its concentrations are particularly high in heart muscle, retina, and brain, where it is essential for growth and proper tissue function. DHA is found mainly in the form of phospholipids, while EPA can occur as a cholesterol ester, triglyceride, or phospholipid.
The body does not know how to produce alpha-linolenic acid(ALA), the precursor of biologically active Omega-3 (EPA and DHA). What's more, the efficiency of converting ALA to EPA and DHA is very low; in fact, it is estimated that less than 0.1% of the alpha-linoleic acid introduced into the body is converted to DHA.
The limitations imposed by this inefficiency can be addressed by providing the body with ready-to-use EPA and DHA in the form of fish oil.
At present, fish oil, a source of Omega-3, is mainly used to promote good heart health and to promote the development and functioning of the brain and eyesight. However, its Omega-3s are also proposed in other situations, such as against inflammatory diseases, to those who practice sports, against dermatological problems, and sometimes even to reduce the risk of developing certain forms of cancer.
Nutritional properties of fish oil: fatty acids and vitamins
Some of the fish oil on the market is obtained from fish liver. This iscod liver oil, a product rich not only in omega-3 fatty acids but also in vitamin A and vitamin D.
Generally, however, when we talk about fish oil we are referring to a product that contains mainly Omega-3s and is obtained not from the liver but from the muscles of fish.
In a sense, cod liver oil can be considered a fish oil with vitamin D and A.
If, on the other hand, you are looking for fish oil with vitamin E, you can purchase products in which this nutrient has been added to the purified fish oil.
How to use fish oil?
Fish oil can be taken orally in supplement form. However, it is important to know how many grams per day of fish oil they provide.
Efsa provides precise guidance in this regard, stressing that in order to claim beneficial properties, products containing EPA and DHA must provide precise amounts of them. Specifically:
- to maintain normal blood pressure they need to provide 3 grams of EPA+DHA per day;
- To keep triglycerides in the normal range, they need to provide 2 grams of EPA+DHA per day;
- to promote good heart function they need to provide 250 mg EPA+DHA daily.
In addition, Efsa recommends that EPA+DHA doses of more than 5 grams per day should not be taken with supplements.
When should fish oil not be used?
Fish oil should not be used in case of allergies to its components.
In addition, caution should be exercised under special conditions, such as pregnancy and lactation, if you are taking medications, and if you have specific medical conditions. In these cases you should consult with your doctor before taking them.
Fish oil: benefits and properties
The properties of fish oil depend on the polyunsaturated fatty acids found within it, the Omega-3 which by exerting important biological actions are able to influence various cellular functions.
What benefits has fish oil shown over the course of studies?
Most of the available data on the effects of Omega-3s from marine sources such as fish oil relate to their benefits to the heartand blood vessels.
These fatty acids have been associated with lower cardiovascular risk, stabilization of heart rate, reduced mortality in patients with coronary artery disease, lower blood clotting tendency, and lower risk of experiencing a second heart attack.
Studies suggest that increased fish oil intake helps improve several parameters associated with hemodynamic and cardiac function, such as blood pressure, vascular tone, and heart muscle efficiency. In addition, Omega-3s have been associated with improvements in blood lipid levels.
Finally, fish oil has been associated with antifibrotic and anti-inflammatory effects that could, in the long run, reduce the occurrence of irreversible changes in the structure or function of the atria, the upper cavities of the heart.
At present, it is believed that the protection offered by Omega-3s against cardiovascular disease depends on the reduction of blood pressure, heart rate, tendency to thrombosis, ' inflammation and arrhythmias, and to an improvement in endothelium (the epithelium of blood vessels) function, insulin sensitivity, paraoxonase (an enzyme that counteracts oxidation of "bad" cholesterol) concentrations, and stability of atherosclerotic plaques.
The resulting protection from cardiovascular events, cardiac death, and coronary events appears to be particularly significant in people characterized by high cardiovascular risk. Drugs, therefore, are not the only allies against heart problems: statins and fish oil are both friends of cardiovascular health.
However, the potential beneficial effects of fish oil are not limited to the heart. In fact, Omega-3 intake has also been associated with a reduced risk of cerebrovascular problems. In addition, these polyunsaturated fatty acids also appear to protect against depression.
In addition, EPA levels may influence several physiological processes that are critical for the proper functioning of the immune system and involved in the occurrence of autoimmune diseases (such as arthritis, systemic lupus erythematosus, and asthma) and cancer. Some population-based studies suggest that diets rich in Omega-3s may also be associated with a lower incidence of some forms of cancer, but evidence to date is mixed.
Finally, taking Omega-3 supplements could help reduceinflammationandfat accumulation in the liver.
What drugs or foods can modify the effect of fish oil?
Before taking fish oil, it is a good idea to consult your doctor about possible interactions with other medications, particularly:
- estrogen (found in the birth control pill and hormone replacement therapies)
- anticoagulants (such as warfarin)
- beta blockers
- diuretics
Regarding, however, evetual doubts about how to use fish oil and foods in such a way as to obtain the greatest possible benefits, it is important to know that it is not necessary to take fish oil on an empty stomach; on the contrary. Products in which Omega-3s are present in the form of ethyl esters are best absorbed when taken with high-fat meals, which can sufficiently stimulate pancreatic lipase.
Contraindications and side effects
Fish oil should not be taken by those who are allergic to fish or soy.
You should also consult with your doctor before taking it during pregnancy and breastfeeding, if you have liver or pancreatic disease, diabetes or hypothyroidism, and if you drink more than 2 alcoholic drinks a day.
The possible side effects of Omega-3s found in fish oil are listed in Table 1.
Table 1. Possible side effects of Omega-3
|
Gastrointestinal |
Poor digestion, dyspesia, nausea, gastrointestinal disorders. Gastrointestinal bleeding, gastroenteritis. Gastrointestinal pain. |
|
Dermatological |
Skin rash, atopic dermatitis, hives, acne, itching |
|
Cardiovascular |
Low pressure |
|
Musculoskeletal |
Back pain |
|
Metabolic |
Hyperglycemia, goiter, hypertriglyceridemia, increased blood lactate dehydrogenase |
|
Nervous system |
Taste disorders, dizziness, headaches, hyperactivity |
|
Respirators |
Nosebleed, nasal dryness, flu |
|
Hematological |
Increased white blood cell count, slight increase in bleeding time, bleeding |
|
Psychiatric |
Tics, mood swings, insomnia |
|
Hepatics |
Increased ALT, AST and transaminases |
|
Hypersensitivity |
Hypersensitivity reactions, anaphylactic reactions |
|
More |
Infections, pain |
Who needs fish oil?
There is certainly no shortage of research that points to the possible benefits of fish oil. What is the purpose of taking it?
Because of its richness in Omega-3s, fish oil therapy can be helpful in meeting daily requirements for EPA and DHA when one does not eat enough fish rich in these fatty acids, in promoting good development of the nervous system and eyesight, and in combating health problems that could benefit from their properties.
In particular, there is a relationship between triglyceride levels and fish oil, which can help keep them under control.
As for cholesterol and fish oil, on the other hand, this source of Omega-3 may help to promote the increase of so-called "good cholesterol." Generally, however, fish oil is not recommended for lowering bad cholesterol.
Also proposed is fish oil for acne, fish oil against disorders affecting the joints (e.g., fish oil for rheumatoid arthritis, or in cases of osteoarthritis), fish oil for psoriasis, fish oil for fatty liver, fish oil for memory, to stimulate cognitive processes, and to counteract disorders of the psychiatric sphere (such as depression and dementia).
Fish oil in special cases: diabetes, pregnancy, and infancy.
Regarding the relationship between diabetes and fish oil, some studies suggest that fish oil supplements may help reduce the risk of type 2 diabetes. In those who already have it, on the other hand, Omega-3s might help keep triglycerides under control; however, it is not excluded that they might promote an increase in "bad" cholesterol. Finally, these polyunsaturated fatty acids could be helpful in treating type 1 diabetes.
DHA is especially useful during pregnancy. Meeting its requirements is important for proper development of the baby's central nervous system and eyes. Unfortunately, however, this cannot be done simply by eating fish rich in Omega-3, because its consumption must be limited because of the risk of contamination with mercury, a neurotoxic substance.
For the same reason, taking DHA supplements is also recommended for breastfeeding women.
In either case, 200 mg of DHA more than the 250 mg of EPA+DHA normally recommended in adulthood is needed to promote the desired effects, and in either case before taking fish oil or any other dietary supplement you should consult with a physician.
Fish oil for children could also help children struggling with attention-deficit/hyperactivity disorder(ADHD) or sleep disorders.
Fish oil for physical activity, sports and the gym
Finally, Omega-3s could also be useful for those who exercise. However, fish oil should not be taken to increase muscle mass, but to prevent and treat any injuries.
Underlying this benefit would be the anti-inflammatory action of Omega-3s, which also could be helpful in combating so-called "athlete's anemia" as well.
In addition, it is hypothesized that by positively influencing mood and reaction time, Omega-3s may also exert a positive effect on sports performance.
Posology: how much fish oil to take per day?
Suggesting how much fish oil to take daily are recent Food and Agriculture Organization (FAO) recommendations of 250 mg EPA+DHA daily for men and women who are not pregnant or breastfeeding.
In contrast, no minimum limit has been set for the intake of these two omega-3s taken individually.
Where to buy it and how much to spend for a good fish oil supplement
Once you have decided to take Omega-3, a question may arise: where can I buy fish oil?
You can buy it in pharmacies, parapharmacies, herbal shops and even on the Web. However, you should always be careful where you buy fish oilin the Internet and always rely only on safe channels of Promo .
How to figure out, instead, which fish oil to choose? Price can guide the choice because it depends on the quality characteristics of the supplement we are looking at: choosing a low-cost product could mean choosing a poor quality product.
To learn how to choose a good fish oil, one must first know what parameters to consider when judging its quality. The industry includes color, odor and taste, the presence of insoluble impurities, iron, copper, nickel, soaps and free fatty acids, and the degree of peroxidation (which depend on how the fish oil is obtained), and it relies on third-party laboratories to certify the goodness of its products.
Among those most often chosen are Nutrasource Diagnostics Inc.'s International Fish Oil Standards(Ifos) program laboratories, which are based on the reference standards set by the Global Organization for EPA and DHA Omega-3s (Goed).
The IFOS program (the only one dedicated exclusively to fish oil) certifies purity, freshness and concentration of fish oil supplements by testing them batch by batch. The evaluations include.:
- The amount of EPA+DHA compared with that stated on the label;
- The presence of contaminants (polychlorinated biphenyls - PCBs - total, dioxins, furans and dioxin-like PBCs) and heavy metals (mercury, lead, total arsenic, cadmium)
- the stability of the product
IFOS-certified fish oil can be awarded a maximum of 5 stars, each corresponding to a specific criterion among:
- Correspondence between the detected concentration of active ingredients and the labeled concentration;
- An oxidation of less than 75% of the standard specified by the Council for Responsible Nutrition (Crn);
- PCB levels below 50% of the Crn standard;
- dioxin levels below 50 percent of the World Health Organization (WHO) standard;
- The assignment of positive ratings in all tests to which the product has been subjected.
The Ifos program awarded 5 stars on all product lots of Omegor Vitality, VitaDHA 1000 and Meaquor 900.
In addition to the presence of quality certifications, however, the evaluation of the affordability of a fish oil supplement must also be based on the total EPA+DHA content per package of fish oil supplement. How many capsules per day should be taken to reach the recommended doses? The higher this number, the more packs one will have to buy, and on balance, a price that may seem affordable at first glance may not be.
Therefore, it is important to consider the total EPA+DHA content per package. To get this, simply multiply the EPA and DHA content per capsule by the number of capsules. From this you can trace the price per 1,000 mg of EPA+DHA (just divide the price per pack by the EPA+DHA content per pack) and use the latter to compare different supplements and identify the cheapest one.
Bibliography
Adeyemi WJ, Olayaki LA. Effects of single or combined administration of salmon calcitonin and omega-3 fatty acids vs. diclofenac sodium in monoiodoacetate-induced knee osteoarthritis in male Wistar rats. J Basic Clin Physiol Pharmacol. 2017 Nov 27;28(6):573-582
Averna MR et Al. Omega 3 and cardiovascular risk reduction. PPG Scientific Editions, 2003
Baker EJ et Al. Metabolism and functional effects of plant-derived omega-3 fatty acids in humans. Prog Lipid Res. 2016 Oct;64:30-56. doi: 10.1016/j.plipres.2016.07.002. Epub 2016 Aug 3
Berbert AA et Al. Supplementation of fish oil in patients with rheumatoid arthritis. Nutrition. 2005 Feb;21(2):131-6
Bi X et Al. ω-3 polyunsaturated fatty acids ameliorate type 1 diabetes and autoimmunity. J Clin Invest. 2017 May 1;127(5):1757-1771
Bourre JM. Roles of unsaturated fatty acids (especially omega-3 fatty acids) in the brain at various ages and during aging. J Nutr Health Aging. 2004;8(3):163-74
Burke MF1 et Al. Review of Cardiometabolic Effects of Prescription Omega-3 Fatty Acids. Curr Atheroscler Rep. 2017 Nov 7;19(12):60
Chilton FH et Al. Precision Nutrition and Omega-3 Polyunsaturated Fatty Acids: A Case for Personalized Supplementation Approaches for the Prevention and Management of Human Diseases. Nutrients. 2017 Oct 25;9(11)
Conklin SM et Al. Serum omega-3 fatty acids are associated with variation in mood, personality and behavior in hypercholesterolemic community volunteers. Psychiatry Res. 2007 Jul 30;152(1):1-10. Epub 2007 Mar 23
Davidson MH et Al. A novel omega-3 free fatty acid formulation has dramatically improved bioavailability during a low-fat diet compared with omega-3-acid ethyl esters: the ECLIPSE (Epanova(®) compared to Lovaza(®) in a pharmacokinetic single-dose evaluation) study. J Clin Lipidol. 2012 Nov-Dec;6(6):573-84. doi: 10.1016/j.jacl.2012.01.002. Epub 2012 Jan 24.
Drugs.com. Omega-3 Fatty Acid Capsules
Drugs.com. Fish Oil
Ellulu MS et Al. Role of fish oil in human health and possible mechanism to reduce inflammation. Inflammopharmacology. 2015 Jun;23(2-3):79-89. doi: 10.1007/s10787-015-0228-1. Epub 2015 Feb 14.
EU Register of nutrition and health claims made on foods
European Food Safety Authority. Scientific Opinion on Fish Oil for Human Consumption. Food Hygiene, including Rancicity. EFSA Panel on Biological Hazards (BIOHAZ). EFSA Journal 2010,8(10):1874
Fontani G et Al. Cognitive and physiological effects of omega-3 polyunsaturated fatty acid supplementation in healthy subjects. Eur J Clin Invest. 2005 Nov;35(11):691-9
Germano M et Al. Plasma, red blood cells phospholipids and clinical evaluation after long chain omega-3 supplementation in children with attention deficit hyperactivity disorder (ADHD). Nutr Neurosci. 2007 Feb-Apr;10(1-2):1-9
Gioxari A et Al. Intake of ω-3 polyunsaturated fatty acids in patients with rheumatoid arthritis: A systematic review and meta-analysis. Nutrition. 2018 Jan;45:114-124.e4
Grimble RF, Tappia PS. Modulation of pro-inflammatory cytokine biology by unsaturated fatty acids. Z Ernahrungswiss. 1998;37 Suppl 1:57-65
Harris WS. Achieving optimal n-3 fatty acid status: the vegetarian's challenge...or not. Am J Clin Nutr. 2014 Jul;100 Suppl 1:449S-52S. doi: 10.3945/ajcn.113.071324. Epub 2014 Jun 4
Hartweg J et Al. Omega-3 polyunsaturated fatty acids (PUFAs) for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD003205
Hussein N et Al. Long-chain conversion of [13C]linoleic acid and a-linolenic acid in response to marked changes in their dietary intake in men. J. Lipid. Res. 46: 269-280, 2005
IFOS - The international fish oil standards program
Jeppesen C et Al. Omega-3 and omega-6 fatty acids and type 2 diabetes. Curr Diab Rep. 2013 Apr;13(2):279-88
Johnson EJ et Al. The influence of supplemental lutein and docosahexaenoic acid on serum, lipoproteins, and macular pigmentation. Am J Clin Nutr. 2008 May;87(5):1521-9
Jung JY et Al. Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomized, double-blind, controlled trial. Acta Derm Venereol. 2014 Sep;94(5):521-5
Kim JH et Al. Conjugated Linoleic Acid: Potential Health Benefits as a Functional Food Ingredient. Annu Rev Food Sci Technol. 2016;7:221-44
Koba K, Yanagita T. Health benefits of conjugated linoleic acid (CLA). Obes Res Clin Pract. 2014 Nov-Dec;8(6):e525-32
Lauritzen L et Al. Maternal fish oil supplementation in lactation: effect on visual acuity and n-3 fatty acid content of infant erythrocytes. Lipids. 2004 Mar;39(3):195-206
MedlinePlus. Omega-3 fats: Good for your heart
MedlinePlus. Omega-3 Fatty Acids
Merriam-Webster. Definition of FISH OIL.
Miller PE et Al. Long-chain omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid and blood pressure: a meta-analysis of randomized controlled trials. Am J Hypertens. 2014 Jul;27(7):885-96. doi: 10.1093/ajh/hpu024. Epub 2014 Mar 6
Neuringer M et Al. The role of n-3 fatty acids in visual and cognitive development: current evidence and methods of assessment. J Pediatr. 1994 Nov;125(5 Pt 2):S39-47
NIH. Omega-3 Fatty Acids
NIH. Omega-3 Supplements: In Depth
Pawlosky, R. J., et al . Physiological compartmental analysis of alpha-linolenic acid metabolism in adult humans. J. Lipid Res. 42(8):1257-1265, 2001
Poli A. Omega-3 fatty acids and cardiovascular prevention. Trends in Medicine vol 2 num 3, PPG Scientific Editions, 2002
Querques G, Souied EH. The role of omega-3 and micronutrients in age-related macular degeneration. Surv Ophthalmol. 2014 Sep-Oct;59(5):532-9
Scientific Report, "Omega-3 fatty acids. New 2014 Edition. Edited by Zone Academy in collaboration with Inflammation Research Foundation, Boston.
Saldeen P, Saldeen T. Women and omega-3 fatty acids. Obstet Gynecol Surv. 2004 Oct;59(10):722-30; quiz 745-6
SINU. 2014 LARN Tables.
University of Colorado - Colorado Springs. Omega-3, 6, and 9 and How They Add Up.
Zhang M et Al. Fish and marine omega-3 polyunsatured Fatty Acid consumption and incidence of type 2 diabetes: a systematic review and meta-analysis. Int J Endocrinol. 2013;2013:501015