Way back in the 1970s, Danish researchers Hans Olaf Bang and Jorn Dyerberg studied the Inuit population in Greenland and found that despite their meals full of marine fish fat and whale blubber, they had a very low concentration of triglycerides and low-density lipoproteins or the bad cholesterol in the blood.1 The polyunsaturated fatty acids (PUFAs) in fish fat is what made the Inuit somewhat immune to death by heart disease, concluded the two researchers. That’s when fish oil took off as the must-have nutritional supplement for Americans.
Some Fats Are Good, Such As The Omega-3 Fats
These PUFAs or omega-3 fatty acids include eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two of the three essential omega-3 fatty acids the body cannot produce and must derive from food sources like fish or fish oil, the third one being alpha-linolenic acid (ALA), derived from plant sources like nuts and seeds. The human body can convert some of the ALA into EPA and DHA but not efficiently or in sufficient quantities.
You Find Omega-3 In Fish And Fish Oil
Of course, whole fish is most beneficial. But these days, fish also contains a high level of mercury in thanks to pollution. Hence, the oil extracted from the tissues of cold-water oily fish like mackerel, sardine, late trout, herring, albacore tuna, and salmon, which is sold as syrups or pills, remains the source of choice for these omega-3 fatty acids.
Until recently, fish oil was touted to be a panacea thanks to its omega-3 content, but more and more findings suggest that it may not be an absolute champion after all. Let’s take a look at the purported health benefits of omega 3 fatty acids.
Benefits Of Fish Oil
For The Heart
Fish oil omega-3 fatty acids bring down triglyceride levels.
In clinically used doses of 4 g per day, fish oil omega-3 fats can reduce high triglyceride levels and help in primary and secondary prevention of coronary artery disease.2
But other than that, its role in reducing irregular heart beat rate or arrhythmia, heart attack, heart failure, and heart disease–related death is still debatable. Unless you develop good eating habits and exercise regularly, the benefits of fish oil supplementation might be minimal.3
Lower Cholesterol And Blood Pressure
A 1993 analysis of 31 clinical trials found that for every gram of fish oil consumed, there was a drop in blood pressure in the range of 0.66/0.35 mm Hg. The study stressed that people with high blood pressure, high cholesterol, and atherosclerosis would experience the pressure-lowering effect the most.4
For The Brain And The Nerves
Attention Deficit/Hyperactivity Disorder
Fish oil improves the condition of ADHD patients but cannot completely cure them.
Studies claim that a lack of long-chain polyunsaturated fatty acids or omega-3 fatty acids is linked to a number of psychiatric problems, including developmental problems such as attention deficit/hyperactivity disorder (ADHD). 5 This is because EPA helps in the development and functioning of the brain by influencing chemicals like serotonin and dopamine.
But it has been found that though fish oil helps children and adolescents with ADHD, it does so only modestly compared with the conventional treatment available now.6
So unless you are averse to drugs for psychiatric disorders, do not substitute the regular medicines with fish oil. Rather, supplement them with fish oil in your diet.
Fish oil can help prevent Alzheimer’s provided you don’t have the gene that makes you vulnerable to it.
A lower level of DHA in the blood increases the risk of dementia or Alzheimer’s Disease (AD), claim a number of studies.7 This is because DHA can increase the production of the LR11 protein, which destroys the “plaques” or clusters of protein that accumulate between nerve cells and lead to late-onset AD.8
But recent research finds that fish oil supplementation works best for people who haven’t developed AD already and do not have the gene variant (APOE ε4) that makes them susceptible to AD.9
Eating fish helps more than eating just omega-3 fats. For every 100 g increase in your fish intake per week, the risk goes down by 11 percent.10 If you can’t have fish, have fish oil, but start early and combine it with an antioxidant.11
Anxiety And Depression
You should start taking fish oil early, especially at critical periods of brain development, to prevent anxiety symptoms.
A study found that eating a moderate quantity of fish, 83.3 g and 112 g a day, to be precise, reduced the risk of mental disorder by 30 percent.12 Another found that fish oil supplements can reduce anxiety symptoms by 20 percent in healthy people. This is further helped by reducing the ratio of omega-6 and 3 fats.13
In an animal study, all the symptoms of depression and anxiety that were artificially induced in rats could be reversed with fish oil supplementation. The study stressed on the importance of supplementing the diet with fish oil during critical periods of brain development,14 which is why you are advised to start early.
Even if you don’t have anxiety but just major depression, fish oil can help, says a recent large-scale clinical study that found that omega-3 fatty acids help treat major depression.15
However, it is not a substitute for antidepressants or mood stabilizers. And even if you do take it alongside your regular treatment, it’s best to ask your doctor first.16
For The Bones And The Joints
The body converts a substance in fish oil to Resolvin D2, an anti-inflammatory agent.
People suffering from rheumatoid arthritis have good news in fish oil. A study from the University of London and Harvard Medical School has found that the body converts a component in fish oil to a chemical known as Resolvin D2, which helps reduce the inflammation responsible for a number of diseases without suppressing the immune system.17
In one study, consuming more than 2.7 g omega-3 PUFAs for more than 3 months also brings down the need to take standard nonsteroidal anti-inflammatory drugs (NSAIDs) for tender or swollen joints and reduces the duration of morning stiffness.18
Fish oil can replace commercial nonsteroidal anti-inflammatory drugs.
Recent research has found that the omega-3 fats in fish oil can reduce the signs and symptoms of osteoarthritis,19 and it is even recommended as a substitute for NSAIDs when it comes to neck and back pain.20
For The Eye
Fish oil may protect against eye disorders and blindness caused by an abnormal growth of blood vessels in the eye,21 which is the cause of premature retinopathy or diabetic retinopathy. A daily dose of 500 mg fish oil can bring down the risk of diabetic retinopathy or eye damage caused by diabetes by 48 percent.22
The omega-3 PUFAs may be used instead of or as a supplement to the anti–vascular endothelial growth factor (VGEF) treatment that suppresses the VGEF protein, which lead to the generation of new blood vessels.23
For The Skin
Omega-3 fats have been seen to reduce symptoms of eczema by decreasing the levels of leukotriene B4, an inflammatory chemical that plays a role in eczema.24 A study found that a daily dose of 10 g fish oil, of which EPA comprised 1.8 g, significantly reduced the symptoms of eczema.25
For The Immune System
A 2013 report established that the DHA in fish oil increases the activity of B cells, a kind of white blood cells that secrete antibodies and are an essential part of your immune system. This finding challenges the previous notion that fish oil suppresses immune function.26
For Fertility And Pregnancy
If you are pregnant, start having omega-3 fats to ensure a healthy nervous system for your baby as well as early development of vision. It will help you avoid labor and delivery before time and reduce the risk of pre-eclampsia caused by placental malfunction. It will also reduce your risk of depression after the baby’s birth.27
In Lowering Obesity And Promoting Weight Loss
It increases the rate of fat cell death.
While animal studies have found that mice fed with fish oil gained less weight than mice fed with other dietary oils, human studies are yet to establish fish oil’s efficacy in combating obesity.
However, fish oil does increase fat cell death as well as the level of adiponectin in the blood, which is a protein that helps in glucose metabolism and fatty acid breakdown. It may also help reduce the waist-to-hip ratio in overweight or obese adults when other lifestyle factors are changed.28
In Preventing Cancer
The omega-3 fatty acids in fish oil can bring down breast cancer risk by 14% and make tumor cells sensitive to chemotherapy.
Omega-3 fatty acids in marine fish bring down the production of enzymes that help in the growth of cancer cells. The PUFAs also increase the rate of cancer cell death and decrease the rate of the formation of new blood vessels that help the cancer cells grow.
One study found that they brought down the risk of breast cancer by 14 percent, with the risk reducing by 5 percent for a daily increment of 0.1 g.29
They can make tumor cells more sensitive to chemotherapy and have been seen to reduce the side effects of 5-Fluorouracil (5-FU), a common drug used to treat colorectal cancer.30 The omega-3 fatty acids can also reduce the ill effects of the animal fats that trigger breast and colorectal cancer.31 It has been seen that cutting down on omega-6 fats and taking in more of omega-3s helps delay the development and progression of prostate cancer.32
The American Institute for Cancer Research recommends eating 3-ounce servings of different types of fatty fish twice a week and also reducing the intake of omega-6 fats.
In Preventing Diabetes
Fish oil helps prevent diabetes but is not recommended for people who are already suffering from diabetes.
A study published in Nature found that a higher level of omega-3 fatty acids in the body led to a higher insulin sensitivity. This was also responsible for lower systolic blood pressure, fasting insulin level, levels of the protein CRP—which increases in cases of inflammation—and free fatty acids in middle-aged overweight men. To summarize, fish oil is a good preventative against diabetes.33
But if you already have diabetes, you would better consult your doctor about whether you should have fish oil because fish oil supplements also affect glucose metabolism negatively and may show a spike in blood glucose levels because of the extra fat intake.34
In Fighting Aging
Aging causes telomeres, the caps at the ends of a DNA strand, to shorten. A study found that increasing omega-3 fats in the diet rather than other fats slows down aging by lengthening the telomeres in the DNA. This is probably because they reduce ill effects of cell-damaging free radicals in the body.35
In Reducing Period Pain (Dysmenorrhea)
Abdominal cramps during menstruation is very common among adolescent girls and women of child-bearing age. Because the omega-3 fats in fish oil lower inflammation, they are effective in reducing menstrual pain. In fact, they are more effective than Ibuprofen, a standard NSAID.36 But if you are on blood-thinning medication, consult a doctor before you pop in fish oil pills.37
How Much Omega-3 Do You Need?
European adults are advised to have 250–500 mg omega-3 fats a day to avert risk of cardiovascular diseases, but 1 g DHA alone and 1.8 g EPA alone per day is not risky.38
The American Heart Association recommends that heart patients have a total of 1 g EPA and DHA at least twice a week and patients with very high triglyceride levels take 2–4 g a day. But if you consume more than 3 g a day, do consult your doctor first.
The Omega-6 and Omega-3 Fat Ratio Is Crucial
Another important factor is the ratio of omega-6 fats, found in vegetable oils, and omega-3 fats. While an ideal ratio is 1:1, most Western diets have a 15:1 to 16.7:1 ratio,39 with an excess of omega-6 fatty acids that have an inflammatory function compared with omega-3 fats that suppress inflammation. So it’s not enough to increase your omega-3 intake. You need to bring down your omega-6 intake simultaneously.
A Word Of Caution
Though recent research has shown that fish oil is not always as effective and potent as it has been so far touted to be, it has very few harmful effects except for diabetics and patients on blood thinners. While the altered energy expenditure caused by fish oil is not good for diabetics, the anti–blood clotting effect is not good for people on blood-thinning medication either.
That apart, it’s necessary to take fish oil along with antioxidants because the process of extraction and refining of fish oil may often make it oxidized and unsafe for consumption.40
|↑1||Bang, H. O., J. Dyerberg, and N. Hjørne. “The composition of food consumed by Greenland Eskimos.” Acta Medica Scandinavica 200, no. 1‐6 (1976): 69-73.|
|↑2||Weitz, Daniel, Howard Weintraub, Edward Fisher, and Arthur Z. Schwartzbard. “Fish oil for the treatment of cardiovascular disease.” Cardiology in review 18, no. 5 (2010): 258.|
|↑3||Mohebi-Nejad, Azin, and Behnood Bikdeli. “Omega-3 supplements and cardiovascular diseases.” Tanaffos 13, no. 1 (2014): 6.|
|↑4||Morris, Martha Clare, Frank Sacks, and Bernard Rosner. “Does fish oil lower blood pressure? A meta-analysis of controlled trials.” Circulation 88, no. 2 (1993): 523-533.|
|↑5||Sinn, Natalie, Catherine Milte, and Peter RC Howe. “Oiling the brain: a review of randomized controlled trials of omega-3 fatty acids in psychopathology across the lifespan.” Nutrients 2, no. 2 (2010): 128-170.|
|↑6||Bloch, Michael H., and Ahmad Qawasmi. “Omega-3 fatty acid supplementation for the treatment of children with attention-deficit/hyperactivity disorder symptomatology: systematic review and meta-analysis.” Journal of the American Academy of Child & Adolescent Psychiatry 50, no. 10 (2011): 991-1000.|
|↑7, ↑11||Cole, Greg M., Qiu-Lan Ma, and Sally A. Frautschy. “Omega-3 fatty acids and dementia.” Prostaglandins, Leukotrienes and Essential Fatty Acids 81, no. 2 (2009): 213-221.|
|↑8||Ma, Qiu-Lan, Bruce Teter, Oliver J. Ubeda, Takashi Morihara, Dilsher Dhoot, Michael D. Nyby, Michael L. Tuck, Sally A. Frautschy, and Greg M. Cole. “Omega-3 fatty acid docosahexaenoic acid increases SorLA/LR11, a sorting protein with reduced expression in sporadic Alzheimer’s disease (AD): relevance to AD prevention.” The Journal of Neuroscience 27, no. 52 (2007): 14299-14307.|
|↑9||Daiello, Lori A., Assawin Gongvatana, Shira Dunsiger, Ronald A. Cohen, Brian R. Ott, and Alzheimer’s Disease Neuroimaging Initiative. “Association of fish oil supplement use with preservation of brain volume and cognitive function.” Alzheimer’s & Dementia 11, no. 2 (2015): 226-235.|
|↑10||Wu, Shunquan, Yingying Ding, Fuquan Wu, Ruisheng Li, Jun Hou, and Panyong Mao. “Omega-3 fatty acids intake and risks of dementia and Alzheimer’s disease: A meta-analysis.” Neuroscience & Biobehavioral Reviews 48 (2015): 1-9.|
|↑12||Sanchez-Villegas, Almudena, Patricia Henríquez, Adolfo Figueiras, Felipe Ortuño, Francisca Lahortiga, and Miguel A. Martínez-González. “Long chain omega-3 fatty acids intake, fish consumption and mental disorders in the SUN cohort study.” European journal of nutrition 46, no. 6 (2007): 337-346.|
|↑13||Kiecolt-Glaser, Janice K., Martha A. Belury, Rebecca Andridge, William B. Malarkey, and Ronald Glaser. “Omega-3 supplementation lowers inflammation and anxiety in medical students: a randomized controlled trial.” Brain, behavior, and immunity 25, no. 8 (2011): 1725-1734.|
|↑14||Pudell, Claudia, Bianca A. Vicente, Ana M. Delattre, Bruno Carabelli, Marco A. Mori, Deborah Suchecki, Ricardo B. Machado et al. “Fish oil improves anxiety‐like, depressive‐like and cognitive behaviors in olfactory bulbectomised rats.” European Journal of Neuroscience 39, no. 2 (2014): 266-274.|
|↑15||Lespérance, François, Nancy Frasure-Smith, Elise St-André, Gustavo Turecki, Paul Lespérance, and Stephen R. Wisniewski. “The efficacy of omega-3 supplementation for major depression: a randomized controlled trial.”The Journal of clinical psychiatry 72, no. 8 (2010): 1054-1062.|
|↑16||Sinclair, Andy. “Fish Oil and Depression.” Journal of Complementary Medicine: CM, The 4, no. 1 (2005): 52.|
|↑17||Spite, Matthew, Lucy V. Norling, Lisa Summers, Rong Yang, Dianne Cooper, Nicos A. Petasis, Roderick J. Flower, Mauro Perretti, and Charles N. Serhan. “Resolvin D2 is a potent regulator of leukocytes and controls microbial sepsis.” Nature 461, no. 7268 (2009): 1287-1291.|
|↑18||Lee, Young-Ho, Sang-Cheol Bae, and Gwan-Gyu Song. “Omega-3 polyunsaturated fatty acids and the treatment of rheumatoid arthritis: a meta-analysis.” Archives of medical research 43, no. 5 (2012): 356-362.|
|↑19||Knott, L., N. C. Avery, A. P. Hollander, and J. F. Tarlton. “Regulation of osteoarthritis by omega-3 (n-3) polyunsaturated fatty acids in a naturally occurring model of disease.” Osteoarthritis and Cartilage 19, no. 9 (2011): 1150-1157.|
|↑20||Maroon, Joseph Charles, and Jeffrey W. Bost. “ω-3 Fatty acids (fish oil) as an anti-inflammatory: an alternative to nonsteroidal anti-inflammatory drugs for discogenic pain.” Surgical neurology 65, no. 4 (2006): 326-331.|
|↑21||Connor, Kip M., John Paul SanGiovanni, Chatarina Lofqvist, Christopher M. Aderman, Jing Chen, Akiko Higuchi, Song Hong et al. “Increased dietary intake of ω-3-polyunsaturated fatty acids reduces pathological retinal angiogenesis.” Nature medicine 13, no. 7 (2007): 868-873.|
|↑22||Sala-Vila, Aleix, Andrés Díaz-López, Cinta Valls-Pedret, Montserrat Cofán, Alfredo García-Layana, Rosa-María Lamuela-Raventós, Olga Castañer et al. “Dietary Marine ω-3 Fatty Acids and Incident Sight-Threatening Retinopathy in Middle-Aged and Older Individuals With Type 2 Diabetes: Prospective Investigation From the PREDIMED Trial.” JAMA ophthalmology 134, no. 10 (2016): 1142-1149.|
|↑23||Sapieha, Przemyslaw, Andreas Stahl, Jing Chen, Molly R. Seaward, Keirnan L. Willett, Nathan M. Krah, Roberta J. Dennison et al. “5-Lipoxygenase metabolite 4-HDHA is a mediator of the antiangiogenic effect of ω-3 polyunsaturated fatty acids.” Science translational medicine 3, no. 69 (2011): 69ra12-69ra12.|
|↑24||Eczema. University of Maryland School of Medicine|
|↑25||Bjørneboe, A., E. Søyland, G‐E. A. BJØRNEBOE, G. Rajka, and C. A. Drevon. “Effect of n‐3 fatty acid supplement to patients with atopic dermatitis.” Journal of internal medicine 225, no. S731 (1989): 233-236.|
|↑26||Gurzell, Eric A., Heather Teague, Mitchel Harris, Jonathan Clinthorne, Saame Raza Shaikh, and Jenifer I. Fenton. “DHA-enriched fish oil targets B cell lipid microdomains and enhances ex vivo and in vivo B cell function.” Journal of leukocyte biology 93, no. 4 (2013): 463-470.|
|↑27||Omega-3 Fish Oil and Pregnancy. American Pregnancy Association|
|↑28||Du, Shichun, Jie Jin, Wenjun Fang, and Qing Su. “Does fish oil have an anti-obesity effect in overweight/obese adults? A meta-analysis of randomized controlled trials.” PloS one 10, no. 11 (2015): e0142652.|
|↑29||Zheng, Ju-Sheng, Xiao-Jie Hu, Yi-Min Zhao, Jing Yang, and Duo Li. “Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies.” (2013): f3706.|
|↑30||Rani, Isha, Kim Vaiphei, and Navneet Agnihotri. “Supplementation of fish oil augments efficacy and attenuates toxicity of 5-fluorouracil in 1, 2-dimethylhydrazine dihydrochloride/dextran sulfate sodium-induced colon carcinogenesis.” Cancer chemotherapy and pharmacology 74, no. 2 (2014): 309-322.|
|↑31||Caygill, C. P., A. Charlett, and M. J. Hill. “Fat, fish, fish oil and cancer.” British Journal of Cancer74, no. 1 (1996): 159.|
|↑32||Galet, Colette, Kiran Gollapudi, Sevan Stepanian, Joshua B. Byrd, Susanne M. Henning, Tristan Grogan, David Elashoff et al. “Effect of a low-fat fish oil diet on proinflammatory eicosanoids and cell-cycle progression score in men undergoing radical prostatectomy.” Cancer prevention research 7, no. 1 (2014): 97-104.|
|↑33||Albert, Benjamin B., José GB Derraik, Christine M. Brennan, Janene B. Biggs, Greg C. Smith, Manohar L. Garg, David Cameron-Smith, Paul L. Hofman, and Wayne S. Cutfield. “Higher omega-3 index is associated with increased insulin sensitivity and more favourable metabolic profile in middle-aged overweight men.” Scientific reports 4 (2014): 6697.|
|↑34||Borkman, Mark, Donald J. Chisholm, Stuart M. Furler, Leonard H. Storlien, Edward W. Kraegen, Leon A. Simons, and Colin N. Chesterman. “Effects of fish oil supplementation on glucose and lipid metabolism in NIDDM.” Diabetes 38, no. 10 (1989): 1314-1319.|
|↑35||Kiecolt-Glaser, Janice K., Martha A. Belury, Rebecca Andridge, William B. Malarkey, Beom Seuk Hwang, and Ronald Glaser. “Omega-3 supplementation lowers inflammation in healthy middle-aged and older adults: a randomized controlled trial.” Brain, behavior, and immunity 26, no. 6 (2012): 988-995.|
|↑36||Zafari, Mandana, Fereshteh Behmanesh, and Azar Agha Mohammadi. “Comparison of the effect of fish oil and ibuprofen on treatment of severe pain in primary dysmenorrhea.” Caspian journal of internal medicine 2, no. 3 (2011): 279-282.|
|↑37||Menstrual Pain. University of Maryland School of Medicine|
|↑38||Agostoni, C., J. L. Bresson, S. Fairweather-Tait, A. Flynn, I. Golly, H. Korhonen, P. Lagiou et al. “Scientific opinion on the tolerable upper intake level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA).” EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA), Parma, Italy (2012).|
|↑39||Simopoulos, Artemis P. “The importance of the ratio of omega-6/omega-3 essential fatty acids.” Biomedicine & pharmacotherapy 56, no. 8 (2002): 365-379.|
|↑40||Cameron-Smith, David, Benjamin B. Albert, and Wayne S. Cutfield. “Fishing for answers: is oxidation of fish oil supplements a problem?.” Journal of nutritional science 4 (2015): e36.|