Fish oil capsules: Net benefits for the heart are limited

Every day, millions of people swallow fish oil capsules, many of them lured by the promise that the pills will help them cast off heart disease. In fact, the label of one popular brand includes the line, “May reduce coronary heart disease risk.”

Don’t take the bait: these bold marketing claims haven’t caught up with the latest science. Earlier this year, the American Heart Association (AHA) issued an updated advisory about fish oil supplements and their cardiovascular benefits. Their verdict: fish oil supplements may slightly lower the risk of dying of heart failure or after a recent heart attack. But they do not prevent heart disease.

Angling for advice?

“It’s probably not wise for any middle-aged person to start taking fish oil supplements without the advice of a physician,” says Dr. Eric Rimm, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. Even for people who do have heart disease, the potential benefits are quite modest, he notes. If you’ve had a heart attack, taking about a gram (1,000 mg) of fish oil per day may lower your risk of sudden cardiac death by about 10%. In people with heart failure, fish oil supplements may reduce death and hospitalizations by about 9%.

The AHA’s earlier recommendation, published in 2002, advised people with known heart disease to consume about a gram per day of the omega-3 fatty acids DHA and EPA, ideally from eating fatty fish. But people could also consider omega-3 fatty acid supplements in consultation with a physician.

The early evidence for fish oil supplements looked promising. But over the past 15 years, many trials have compared them with placebos. There is no evidence that taking fish oil supplements offers any benefit for people prone to cardiovascular disease, including those with diabetes, atrial fibrillation, or stroke.

Not necessarily risk-free

Even so, some people — including those who aren’t in that small group who might benefit from the supplement — may be tempted to keep taking fish oil. They figure that it can’t hurt and just might help. But that’s not necessarily true, says Dr. Rimm. Although “there’s still good evidence that eating fish twice a week may help lower heart disease risk,” he says, the concentrated oil found in supplements is not entirely without risk.

As is true for all dietary supplements, there is no oversight or regulation regarding the source, quality, or amount of active ingredient in these over-the-counter products. Some studies have detected trace amounts of polychlorinated biphenyls (PCBs) in some brands of fish oil supplements. Although these industrial chemicals were banned in 1979 after they were linked to cancer, they’re still found in fish exposed to water contaminated from soil runoff. Other research has revealed that some supplement brands don’t provide the amounts of DHA and EPA advertised on their labels.

It’s also worth noting that fish oil may reduce formation of blood clots. That’s potentially beneficial, but only up to a point. Too much fish oil may increase bleeding risk, particularly in people who also take anticlotting medications, including warfarin (Coumadin) and low-dose aspirin.

Many people take low-dose aspirin for heart attack prevention, Dr. Rimm points out. “Taking fish oil on top of that may not only have no benefit, it may even have some risks that we don’t realize because we haven’t studied them.”

Related Information: Healthy Eating for a Healthy Heart


  1. guutu

    Even if you consumed masses of fish oil, whose function is to reduce arterial inflammation, (which leads to calcification), it’s only 1 of the 3 main causes of calcification. The other 2 main causative agents must be addressed, they being high blood homocysteine and high triglycerides.

  2. Patricia Bray

    May I share a personal fact that Carlson’s COD Liver Fish Oil plus D-ribose and acetyl l carnitine
    Plus E Gems Elite Jarrow’s Zinc Balance and Natural Calm Magnesium Citrate Vitamins C E and
    co Q 10 were very vital nutrients instead of pills. Many years ago I had Dr Sherry Rodgers book
    On cardiovascular issues and while sharing it with
    A friend it also became a much needed source of
    Healing in a critical moment along with preparing everything personally that I ate and walking everyday and no electronics only music!! Not all supplements are equal so I followed this Doctor’s
    Research and applied it. The world could use your brain trust being applied on an individual path for consideration and application and sharing together. Imagine the health changes and creativity. Happy New Year to the busy Professors and Doctors at Harvard. I don’t always agree but I enjoy reading and thinking about your articles!

  3. william

    In Asia, people seldom have fish oil, and we all know that the heart problem is also less than the developed areas before. And now , with the economical progress more and more people suffer the heart problem. So that we could guess that the way to treat that problem must be in the way of life of early Asian.

    Regretly, we Asian are lossing their way of life gradually. Such as, the rapeseed oil is the most common oil in Asian kitchen, however, recently I read a book , in which says that the rapeseed oil is bad to the heart health. I am not an expert , but frankly speaking I am not sure of this words.

  4. Thomas Turk

    If anybody’s still on site.. today’s Harvard Health Newsletter by a cardiology Prof at Harvard,.. Saturated fat (in butter and red meat) can harm both memory and artery health. I’ve mentioned the B vitamin synthesis in the gut with cream and butter in another comment. Grass fed animal’s fat is high in artery-protective Om3, LCFAs and CLA. I have eaten globs of butter and the fattest steaks, chops etc since early 70s.

    The red meat cancer connection is also in error. BBQ-burnt meat, (AND even veges), and smoked products develop acrilamides, pyrroles that inflame the colon. An inflamed body part allows the cancer nucleus and complex easy entry into an inflamed part. In the presence of nickel, this will start and fuel a malignancy. Also.. 2nd colon specific inflammatory is acetic acid, vinegar except for apple cider vinegar. Clark H R PhD ND 2007. Rare red meat is and excellent source of the B vitamins especially B12, noting that any strong, short heating, even a quick stir fry.. destroys 90% of B vitamins.

    The mis-direction of Drs. starts in their measly 6 hrs of nutrition in 6 years med school. (My son got 10mins in Vienna Med School). Sadly, even in their 6 hours, they’re taught the cholesterol, calories, food groups, RDAs etc baloney. I once challenged the Prof of Nutrition at a top Far East Med school as to why she taught that, for surely she knew better. She admitted that she had to teach what was in the book! Who mainly funds the Med Unis? Big Pharma. Who would set out what must be taught? Big Phama.. maybe?

  5. Fred Thomas

    If you look into it the United States is about 3-4% of the world’s population yet we take(or prescribed) about 50% of the world’s prescriptions. There is something wrong with that. We have an obesity crisis opioid crisis diabetes running rampant heart disease and cancer epidemic and pain crisis. In Europe the German E commission regulates supplements. They will prescribe CoQ10 before putting you on statin and so on. Most of us are extremely low in Vitamin D and magnesium and most of the vitamins and MINERALS. We are depleted in these and we need to REPLETE for optimum health. Hospitals are growing at an alarming rate but are we any healthier -NO. Sugar is our enemy. I take a few supplements am 65 and feel great my pain level is close to zero. Vitamin D (52.31) level and magnesium malate helped tremendously .

    • Thomas Turk

      FredT. The Sickness Industry in the US is worth 3,5T$ annually. (My son is in Med in US and says, Dad, it’s very profitable). How did they manage to get here, when after WWI hospital beds were MT, Little Pharma made Aspirin, cardiologists and Healthy Eating advice were not yet invented?

      1st the measles vax was brought in from UK by one of Pharmas big shots, Rocky Fellah. The horrific poster of a UK measles damaged child was later found to be of a measles vax. damaged child. In the early 60s, Harvard Med Sch. was conducting a study on sugar. The sugar Ind. set up a team that bribed the Harvard Profs, who then changed their findings and apportioned blame on animal fats. The head of that sugar Ind team then joined U S Agric Dept and tasked with writing up today’s baloney food groups, pyramid, RDAs etc, (From Sugar Ind. docs discovered by the U of SF, 2017)

      And that’s how they keep the trusting population sick, weak and finally medicated for life. They also advise against supplementation. They assure that sugar wth 77 harmful effects, 4 of which kick in within 20 minutes.. is just nutrient-free energy. (Autopsies on 3 year old’s have shown arteries starting calcification from the massive sugar content of baby formulas. Sugar depleted their needed B vitamins, high homocysteine, blocked Vit C action needed for inflammation and soared causative triglycerides). They tell us there is no cure for cancer, yet H R Clark PhD has carried out over 1/2M reproducible bio-resonance test to precisely identify tha many causes nd pathways of all cancers. The1939 UK Cancer Act PROHIBITS ‘official’ publication of any cancer cure In US th e Med Js refuse to publish ay cyure ie Dr R Goods natural pancreatic cancer cure in 1985.

      They tell there’s no cure for R Arthritis, yet the US Agric Dept in 1974 told us it was the solanines in 4 veges. That obesity is a disease, or it’s calories in vs calories out.. when in Human Physiology, (Vander Sherman and Luciano) it’s the carbs that fatten and so on..

      Fake RDAs. We’re told to have a glass of OJ for our immune-boosting Vit C. Yet we need 3gms of vitamin C. plus selenium and germanium to fully rev-up the killer white blood cells, the CD4, CD8 and CD14 leukocytes. (Clark H R PhD ND). They won’t tell that fresh supermarket oranges have been tested with ZERO vitamin C. Nor tell that you need 60 freshly picked, sun ripened oranges and up to 5X that when sick. (Animal studies).

      Why do Reg Dietician repeat the baloney They were exposed as a totally corrupt, self-appointed Org fully funded by Big Food, Biotech and indirectly by Big Pharma.

      Sadly even alternative newsletters ie NaturalNews and Mercola have writers who just copy out Mainstream’s nonsense. I used to comment there but was banned for life on both, maybe upsetting some!

      • Fred Thomas

        Thank You Thomas for the info. We all have to be more proactive in our health and not what Big Pharma dictates. There is a place for med like during surgeries. We need a balance of Eastern And Western Medicine. There is a book called Foundations for Healing by Dr. Richard Becker that is very informative. (He beat cancer) He has a company called Bioinnovations (.net) and is where I get many of my supplements. My blood work now proves that they are working not all the meds they tried to cram down me. I gave a copy to my doctor and she is now checking Vitamin d and magnesium levels (RBC MAG test is most reliable rather than the standard serum level. I am now on Medicare with a new doctor which I have to train. Also I subscribe to Life Extension Magazine which is educational. Thanks and be well!!!!

  6. suma

    Extra ordinary comments by everyone, especially Thomas Turk. Now cureJoy is saying we are not regulated….WE ARE REGULATED. AND HAVE been for decades…Having been in the Holistic Field for over 50 yrs
    since the 1960’s and watched the industry grow. The Healing is here from many centuries…..My Holistic Health Show on the internet (no selling)
    Suma G Nathan, Certified Registered Holistic Health Practitioner
    Certified Chinese Herbologist

  7. Thomas Turk

    Even if you consumed masses of fish oil, whose function is to reduce arterial inflammation, (which leads to calcification), it’s only 1 of the 3 main causes of calcification. The other 2 main causative agents must be addressed, they being high blood homocysteine and high triglycerides. Instead of waiting for fish oil’s weak result.. 2 egg yolks daily, (preferably raw, shells well washed, whites cooked), have have sufficient anti-oxidents from selenium, amino acids l-cysteine, l-tyrosene etc and vitamins to stop all inflammation. Idiotic advice is for 2 yolks a week

    To lower high blood homocysteine you need vitamins B6, B12 and folates. Surprise. Cream an butter synthesize the B vitamins in the gut with the friendly bacteria. Malhotra S L, Dr. The Lancet UK Med J. Pub 11X. Idiotic advice is to avoid cream and butter.

    Triglycerides are causative blood fats elevated by carbs, especially sugar and alcohol Idiotic advice is for hi carb grains 11X/ day.

  8. A Parr

    I have been taking Cod Liver oil for 50 years, would stopping it now cause a problem for me. I have no family history of heart disease.
    I’m from the era that “ a tea spoon a day “ was good for you.

    • Thomas Turk

      You also need to control high homocysteine and triglycerides. See my comment. At 79 my arteries are CLEAN. A recet high speed camera showed this result done during a heart scan. Been on this well documeted but compleely ignore by MS Med diet since early 1970s. If you left it late.. explore EDTA. an amino acid of which you make litte but more will clean out 30Kms of arteries.

  9. rachel courtney

    Dear Julie, How about a product that I’ve been looking at which is a “double dose of high-intensity omega-3 DHA benefits for healthy brain and nervous system support”. It has 410 mg EPA, 960 mg DHA & 290 of other omega3’s. So what was once claimed as help for heart health is now being touted for brain and nervous system health. I’m confused! Would appreciate your thoughts. THANKS
    P.S. They also claim that their product is “tested by a third-party certified lab for environmental toxins, including heavy metals. All fish oils are in the triglyceride form and surpass the strictest international standards for purity and freshness”. And that certificates of analysis are available…

  10. Bonnie Britt

    “Even for people who do have heart disease, the potential benefits are quite modest, [Rimm] notes. If you’ve had a heart attack, taking about a gram (1,000 mg) of fish oil per day may lower your risk of sudden cardiac death by about 10%. In people with heart failure, fish oil supplements may reduce death and hospitalizations by about 9%.”

    What is modest to one person may be life-saving to another. 9% and 10% in these instances can also be seen as significant, assuming the ‘free market’ is not tricking consumers into swallowing PCBs. The latter is, of course, the risk we take by consuming anything sold by a corrupt economic system that places profits over health.

  11. david tsai

    How bout commenting on articles that suggest statins are not as beneficial as we think.
    Expert Rev Clin Pharmacol. 2015 Mar;8(2):189-99. doi: 10.1586/17512433.2015.1011125. Epub 2015 Feb 6.
    Statins stimulate atherosclerosis and heart failure: pharmacological mechanisms.
    Okuyama H1, Langsjoen PH, Hamazaki T, Ogushi Y, Hama R, Kobayashi T, Uchino H.
    J Negat Results Biomed. 2011 May 24;10:6. doi: 10.1186/1477-5751-10-6.
    No connection between the level of exposition to statins in the population and the incidence/mortality of acute myocardial infarction: an ecological study based on Sweden’s municipalities.
    Nilsson S1, Mölstad S, Karlberg C, Karlsson JE, Persson LG.

    • Thomas Turk

      Statins artificially lower the the ‘bad cholesterol’, although in science there’s no such thing. The term is used purely as a scare tactic to market the totally ineffective statins, loaded with their side-effects. i.e. blocking CQ10 production etc.. What you’re not told, IF the doc knows, is that LDL is merely the marker the amount of ongoing arterial inflammation.

      Statins, lacking in the needed anti-oxidants to stop arterial inflammation, can therefor neither slow nor stop arterial calcification. Statins merely artificially alter the LDL ‘reading’ by interfering with normal gut or liver function, that depending on the brand! 2egg yolks daily stop that inflammation with their massive anit-oxidants. See my earlier comment. I eat up to10 yolks daily with at least 3 raw. At 79, arteries are clean. See my earlier comment.

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