Does omega-3 prevent heart disease?

omega 3 prevent heart disease ekg ecg

I have a confession to make. For at least the last ten years, I’ve taken an omega-3 supplement every day. Religiously. Why? I literally have no idea. I don’t remember exactly when or why I started taking it. Presumably I read somewhere that it was a good idea. This was before I started studying medicine, and the decision certainly wasn’t based on any thorough evaluation of the scientific evidence. So I figure it’s probably about time I actually take a look at the evidence, before I decide whether to continue spending hundreds of dollars a year on omega-3 supplements.

The most commonly claimed benefit when it comes to omega-3 is that it prevents heart disease. This dates back to the 1970’s, when it was noted that inuit following a traditional diet rich in meat from whales and seals suffered from remarkably little cardiovascular disease. It was suggested that this might be due to the high levels of omega-3 fatty acids in meat from marine mammals. Of course, correlation is not causation, and I can think of several other major differences between the traditional inuit diet and the standard western diet that could explain the lack of heart disease, such as the complete absence of sugar.

Since then, there have been many randomized trials looking specifically at omega-3 for the prevention of heart disease. In 2018 the Cochrane collaboration carried out a systematic review and meta-analysis, with the goal of answering the question definitively. The review included both randomized controlled trials of omega-3 supplementation and of advice to eat more fatty fish. The requirements for inclusion in the systematic review were that the trials follow participants for at least one year, and provide data on mortality or outcomes related to heart disease.

79 randomized trials were identified that fulfilled these criteria. The total number of participants in the 79 trials was 112,059, which is a nice big number that should allow some pretty firm conclusions to be drawn. 33 of the trials were looking at omega-3 for secondary prevention (i.e. to prevent people who already have heart disease from progressing to more severe disease or death), while the remaining 46 were looking at omega-3 for primary prevention (i.e. to prevent healthy people from developing heart disease in the first place).

71 of the studies were investigating long-chain omega-3 (the kind found in fish), while eight were looking at short-chain omega-3 (the kind found in walnuts and flax seeds).

63 of the studies were of omega-3 supplements, eight were of omega-3 enriched foods (such as for example breakfast spreads), and four were of advice to eat more foods rich in omega-3. In other words, the overwhelming majority of the studies were of fish oil supplements, and that is where the strongest conclusions can be drawn from the results. In the supplement trials, the control group usually received a “placebo” supplement containing some other type of oil (for example olive oil, sunflower oil, or corn oil).

Ok, let’s get to the results.

We’ll start with cardiovascular events, and then move on to overall mortality (the researchers also looked at cardiovascular mortality, but that is a nonsense metric – people care about whether they’re alive or dead, not what cause of death is listed on their death certificate – so I’m not going to bother wasting my time or yours discussing it).

38 of the trials reported on cardiovascular events (for example heart attacks, strokes, and revascularisations). In total, 14,737 participants experienced a cardiovascular event in these trials. That is plenty, so if there is an effect of omega-3, it should be possible to see. Unfortunately, increased intake of omega-3 was not associated in any meaningful reduction in cardiovascular events. There was a tiny 1% reduction in the relative risk of experiencing a cardiovascular event that was nowhere close to being statistically significant.

The lack of effect remained when only studies at low risk of bias were included. Furthermore, there was no sign of a dose-response effect. In other words, no benefit was seen when the higher dose studies were analyzed separately. In fact, the studies giving the highest omega-3 doses had the worst results of all, showing a 9% increased risk of cardiac events (although as with the lower doses the effect wasn’t statistically significant).

Nor was any benefit seen when looking only at studies of secondary prevention, i.e. of people who had already experienced a cardiovascular event, and who should be most likely to benefit from a treatment that decreases the risk of new events. Nor was there any benefit seen when longer term studies (i.e. with more than four years of follow-up) were analyzed separately. Basically, there was no signal that omega-3 had any beneficial effect on heart disease risk whatsoever.

When looking specifically at heart attacks (as opposed to cardiovascular events more generally), the researchers initially found a small 5% reduction in relative risk. However, when they only included studies at low risk of bias, this instead transformed in to a 3% increase in relative risk. I should point out here that we’re talking relative risks, not absolute risks. If we were to talk absolute risks instead, then the 5% decrease in relative risk of a heart attack, even if real, would actually only be a 0.065% decrease in absolute risk, taking you from a 3.80% risk of having a heart attack down to a 3.73% risk – In other words so marginal as to not be remotely worth bothering about even if the results had been statistically significant, which they weren’t. If you’re confused about the difference between relative risk and absolute risk, or the difference between statistical significance and clinical significance, then I recommend you read this.

Ok, so omega-3 doesn’t appear to be useful for preventing heart disease. But it might have other effects that result in an improvement in overall longevity. There are, for instance, those who claim that omega-3 supplements can prevent cancer. If that is the case, then there should be some improvement in overall mortality. Let’s check.

8,189 people died during the follow-up period in the studies that provided mortality data. As with the cardiovascular events, that is plenty of data. Unfortunately, as with the cardiovascular events, increased intake of omega-3 was not associated with any meaningful reduction in overall mortality over the course of follow-up. To be more precise, omega-3 was associated with an extremely marginal 2% reduction in the relative risk of death. As before, the reduction wasn’t anywhere near being statistically significant.

Apart from that, the funnel plot (a type of graph used to look for publication bias – i.e. the fact that researchers are more likely to publish studies that show benefit) suggested that there were some negative studies “missing”. If those were included, the marginal and statistically insignificant reduction in deaths would likely disappear completely.

It isn’t suprising that some studies are missing. Many of the studies of fish oil supplements and omega-3 enriched foods have been produced by companies that sell fish oil supplements and omega-3 enriched foods. It’s likely that they’ve done their best to hide away studies that failed to show benefit.

The lack of effect on mortality remained when the reviewers looked separately at the studies of omega-3 supplements, the studies of fortified foods, and the studies of dietary advice. It also remained when studies were separated based on whether they were looking at primary prevention or secondary prevention. And it remained when studies with more than four years of follow-up were analyzed separately. In other words, there was no signal that an effect started to appear with time.

The lack of effect even remained when the reviewers separated out the studies by dosage, and only looked at the higher dose studies. There was no suggestion of a dose related effect whatsoever, with the studies giving a relatively high 2.4-4.4 grams of omega-3 per day (equivalent to three to five concentrated fish oil capsules) even showing a marginally increased risk of death.

What can we conclude?

Increasing intake of omega-3 does not protect against heart disease. More importantly, it doesn’t appear to result in any improvement in longevity whatsoever. With that being the case, I’m going save myself some money and stop taking omega-3 supplements, at least until I see some real evidence of benefit.

Please provide your e-mail address below and you will get all future articles delivered straight to your inbox the moment they are released.

Join 23.9K other subscribers

89 thoughts on “Does omega-3 prevent heart disease?”

  1. Like you, I used to take a fish oil capsule daily. Then I started eating fresh salmon at least twice a week, and noticed my hair had a sheen on it that wasn’t there before. If oily fish improves my hair, maybe it’s doing other good things out of sight.

    I stopped buying the fish oil. I think adjusting what one eats makes more sense than taking supplements (though I still take Vitamin D and zinc).

  2. I take Omegas for the positive effects it has on my ability to cope with PMS, specifically the mood issues. That alone makes it worthwhile for me.

    1. Yes and I wonder if Sebastian has any interesting data on vitamin-D. One of my pet hypotheses is that ancient (i.e. older than Sebastian) Scandinavians were able to live through their long, sunless winters because of their diet high in oily fish full of pro-hormone D.

  3. Great summary. The question of heart disease may be the wrong question; or rather an incomplete question. Omega 3 is an effective anti-inflammatory agent. How much cardiovascular disease is actually an inflammatory reaction? How many diseases are actually small vessel disease (such as erectile dysfunction, periodontal disease, muscle wasting of old age)? Does omega-3 help in these conditions. In a similar vein: do statins work because they alter cholesterol metabolism or do they work because they are anti-inflammatants? Is this the reason that statins plus omega 3 are better than either alone?

  4. I, too, have been taking daily Omega-3 for at least ten years, and in that time the opinion of family and friends has shifted from ridicule to ardent support, and back to a middle view. That middle view is that it does no harm. Good enough for me.

  5. Probably the only benefit ofOmega 3 is the onesjoints may well remain more supple and therefore less joint stiffness.

  6. I have come to the same conclusion myself. The problem in America, and most of the “Westernized” world is a terrible diet. High Fructose Corn Syrup, Krispy Kreme donuts and the like are what is killing Americans and making Big Pharma rich. The food “industry” makes us sick so BP (and their fake doctors) can “cure” us with their “opiates.” (The one thing I can give the Sacklers credit for is balls. It takes big ones to sell drugs openly and not give a shit. They murdered Pablo Escobar for doing that. And the Sacklers? A slap on the wrist. But I digress…in fact how the hell did I get THERE?)
    Anyhow…anyone want a partially used bottle of Carlson’s fish oil?

  7. Thank you once again, Dr Rushworth. I will finish what I have left of my Omega3 and then stop.

    So, what vitamins do we northerners actually need as supplements? I believe FoHM does not generally recommend any which is probably sound advice…

    Anyway, I take Wellman Plus (that includes Omega3) plus 1000 units of Vitamin D3 daily. (2000 units in the winter…. ). I know after blood analysis that I am a bit low on Vit D during winter months but to be honest I do not know if the supplements make any difference..

  8. The problem with these studies is they are all short term. It may be that the protective effects of fish oils are only apparent after years of intake. You cannot run a 10 or 20 year clinical trial. Their is evidence Omega-3 are anti inflammatory and it’s now recognised inflammation has a significant role in a number of diseases including cardiovascular

    1. I’ve been taking 2000 mgs of omega 3 fish oil each morning and each night for several years. I had bipass surgery five years ago. My wellness doctor told me at my last blood test that he is amazed that I have no inflammation indicated. Omega 3 also thins blood reducing risk of blood clots leading to a potential heart attack. I’m 66 and have no arthritis or joint pain and jog 30 minutes a day. I also take other supplements and eat no red meat or pork or processed carbs. So maybe omega 3 alone won’t be a cure all but in combination with other healthy life style practices it’s been positive for me. Also I’ve never had a heart attack even though I needed bipass surgery after stents failed and pain returned. No pain now.

      1. I’m 76 and I eat a LOT of red meat, but it’s grass-fed and Omega-3. Why? Because meat provides the best balance of all nutrients for man than any other food type. It even beats kale. Therefore it is the best for heart health. There are many myths regarding meat.

  9. I think I read somewhere about Omega-3 balancing omega6 in terms of gut health.
    On that note it would be great to see you do a post on gut health, maybe with a bit about lectins and micronutrients.

  10. I have heard that fish oil helps with joint problems. Generally speaking joint problems don’t kill so they wouldn’t show up in these studies. Are there worthwhile studies which would help me decide whether to take them or not?
    Incidentally I am over 75 and by my thinking, I am probably lacking in some nutrients by virtue of my age. I eat reasonably healthily, and I take high doses of Vits B, C & D, plus magnesium (supposed to help with cramp which I get at night), probiotics, and sometimes flax or fish oil. I used to get about 3 colds per year and now hardly ever have one. Perhaps wrongly I attribute this to the supplements. I avoid the medical profession as much as possible.
    Any comments would be appreciated.

  11. Tack så mycket. Intressant. Det som inte nämns är att alla dessa och liknade studier för andra kosttillskott och läkemedel görs med fabriksfärska produkter. De produkter som konsumenter däremot intar har legat först i företagets lager, sedan i grossistens lager, sedan i handeln och slutligen hemma. Det gör att kvaliten på de kosttilskott vi eventuellt äter är så mycket lägre än de kosttilskott som studierna görs på, att även om studierna visar positiva resultat är det svårt att uppnå dem i verkligheten.

    Oljor härsknar. Var och en som läser detta kan göra ett expriment och klippa sönder en av sina kapslar och lukta på den. Det påstås att en mycket hög andel kommer att vara härskna redan innan vi köper dem.

    1. As Olof Liljeström commented, in Swedish, Omega3 supplements often turn bad easily. Once they have oxidiced the oil will have a negative effect instead, supposedly.
      One way to prevent the oil go rancid is to put the capsules in the freezer, and only get the ones you will use the next few days. I myself is more interested in the possible brain health benefits of Omega 3, than heart health, and if supplementing may help balance the omega 3 and omega 6 ratio.

      1. How long have the capsules been in the bottles from the point of production to the point of purchase?

  12. I often eat sardines on toast, smoked salmon, mackerel pâté. If they don’t do my heart much good I’m not too worried – they taste good and bring variety to my diet.

    Jeeves was sound about eating fish. If one can’t take dietary advice from a fictional valet who should one take it from?

    1. I think the point is that the bread is the villain and the sardine the hero. Perhaps, the best approach is to eat the sardine on an egg or on a lettuce leaf? I have no idea, however.

  13. I personally tske omega3 due to the brain/eye benefits and inflammation in general. There are other metaanalysis that indeed shows benefits for the heart. Statistics nor p-value dogma should never replace scientific reasoning. Its a tool. The mathematical competence is not of highest standard among MDs.

  14. Det är intressant att du nämner att det kan få nnas studier som är påverkade av tillskottstillverkare.
    Men om så är fallet kan det ju likväl vara tvärtom att läkemedelsindustrin vill ha studier som bekräftar att tillskott inte gagnar hälsan alls. Jag håller det inte som omöjligt i alla fall.

  15. Dr. Rushworth,

    Both you and Dr. Kendrick are looking hard at science and diet. There is so much to look at that it is too much for just a few people to look at.

    You definitely need more doctors working in these areas. I’m certain that you could recruit nutritionists like Chris Masterjohn to help. (He only does comments on fb, so I follow him but don’t engage him since I ditched fb.) It would likely help to form an organization or join one that might have people working in roughly the same areas.

    More eyes on the science. More financial support for legal battles. Maybe even crowdfunding to support research into nutrition and questioning medicine’s positions like encouraging the use of statins.

  16. Thank you for the article. I too have taken Omega 3&6 supplements for years but for totally different reasons: I listened to a lecture given by Barbara Wren at the College of Natural Nutrition (which is, no longer), who was an advocate of proper hydration levels in the body at a cellular level. She stated that if the body has a readily available source of omega oils, it can more easily repair and make good quality new cell membranes, across which water molecules can more easily pass and therefore hydrate the cell to a greater degree; better hydrated cells equalled less inflammation in the body generally was her point…

    And personally, I would have thought the Inuit lifestyle – I’m assuming the antithesis of the modern, highly stressed lifestyle of your average North American/European – would have been more of a contributing factor than diet. However, as demonising LDL was probably kicking off in the 1970’s one can see why the diet connection would have been hypothesised.

  17. Thank you Dr Rushworth for this insight into Omega-3. Perhaps it might also be worth looking at the Inuit who started the Omega-3 taking in the first place. If it was omega3 that reduced their cardiac susceptibility to illness in the first place, it must also be considered that their lifestyle over a thousand years of surviving on mostly mammalian flesh would have honed their bodies to making best use of it.

  18. The intake of omega 3 doesn’tell anything about possible health benefits. You have to monitor the omega3/omega6 Quotient to get a trustworthy outcome of a study about this subject.
    Omega 3 has so many functions in our body – everybody should care about covering its requirements.

    1. That was my thought, too – the amount of omega-3 is not important, what is important is that the omega-3:omega-6 ratio is as close to one as possible.

      In other words, if you consume large quantities of seed oils (high in omega-6), all the fish oil (high in omega-3) in the world isn’t going to help you.

      1. That was my thought, too – the amount of omega-3 is not important, what is important is that the “omega-3:omega-6 ratio is as close to one as possible.

        “In other words, if you consume large quantities of seed oils (high in omega-6), all the fish oil (high in omega-3) in the world isn’t going to help you.”

        Gerald Smith, you are absolutely spot on! That’s been the science for 60 years at least. It hasn’t wavered but it sure has been misinterpreted.

      2. I’m none the wiser, those paragraphs appear to contradict one another. Actual values in grammes please. “High” and “All” have no meaning to me in this context.

  19. In my opinion, it really doesn’t matter how much omega-3 you take if your diet is high in carbohydrates, high enough to cause metabolic syndrome. Insulin resistance is the cause not only of diabetes, but of CVD. Salmon sandwiches for lunch with a doughnut for afters washed down with a coke will not end well.

  20. Hello Sebastian

    There are many interesting comments that indicate that you should look closer at the use of Omega-3. The studies you refer to, including the meta, are impossible to do without an army of confounders.
    It reminds me of a friend of mine who avoids products that are sold in health food stores because the people who frequent the stores look old and frail. A simple example of the difference between correlation and causation.
    Actually, the whole method of gold standard placebo controlled double blind randomized trials reminds me of a saying from the birth of IT – Garbage in – Garbage out… GIGO
    It is impossible to study anything by just giving one group the “thing” and another group “nothing” or “another thing”, be it Omega3 against heart failure, D3 against infections, a new pill to lower blood pressure, or even a new pill against headache. Yes, you can do the study, but it will only answer a small percentage of all your questions. The rest is up to the researcher to speculate about.
    Life is much bigger than what science can grasp. From a (western modern) scientific point of view, you should give up avocado and olives because they are expensive. You should just eat white flour and sugar until science present “evidence” that avocados and olives are the better choice. But this it cannot do without running into hordes of confounders.
    For example, the effects on health of European plants, like Indian and Chinese, have been carefully observed for hundreds and in the latter cases thousands of years. Take any of these findings in a modern test and you will certainly debunk them. So, one has to choose between experience and testing.
    Unfortunately, the experience is withheld from us as being unscientific. So, what can we do?
    My advice to you is that you may skip the expensive fish oil but keep eating avocados and olives, which also are expensive. What do you say? And get some sun when “science” says that Vitamin D3 is no good. And eat some berries when science says Vitamin C is of no use at all.

    1. It’s a little bit funny how the “the scientific method doesn’t work” argument gets trotted out every time I write about a supplement that doesn’t work. No-one ever uses that argument when I write about a drug that doesn’t work.

      1. The problem with all these Megatrials is: “If you don’t catch a fish – it doesn’t mean that there is no fish in the lake”. This is an inharent problem of all statistics!

      2. I really sympathize with this comment. Someone with a sincere voice and a flashy presentation will win out every time. Reading the comments above, I wondered why any of them even come to a site such as this. Their “science is already settled”.

      3. Fran
        The Omega-3 science is sound. Sebastian made a mistake. He reviewed studies that did not take into account the tiny impact the supplement had on the Omega-6 to Omega-3 ratio. And it’s the EFA ratio that defines the Omega-3 deficiency. And scientists say it’s ONLY the lowering of the EFA ratio from 15:1 to less than 2:1 that has a positive impact on heart health. Without measuring the change or differences in the EFA ratio of the heart health of two control groups, there is no study. The studies sighted did not measure the impact of the Omega-3 because they made no mention of addressing the deficiency. Noting that someone is merely taking an Omega-3 tablet can in no way have a bearing on changes in their heart health status. It’s impossible. Therefore his analysis was totally and completely irrelevant. It had nothing to do with the professional scientific expectations of the professionals in the lipid arena. He just put together a whole bunch of poorly structured reports and drew a conclusion. I’ve actually written about that kind of mistaken analysis many times and why everyone has to be on-guard against them.

        What his study does do is show that merely taking an Omega-3 supplement is a worthless exercise unless you are focused on checking and changing your EFA ratio. Without a proper goal and an understanding of the science, what’s the use. This was a case of no goal and no science.

      4. Which scientists? What studies? All you’ve done is link to blog posts you’ve written on your web site where you sell omega-3 enriched foods. Your personal conflicts of interest are blatantly clear.

        The claims you make about the importance of the o6:o3 ratio are hardly settled science in spite of your claims to the contrary. They are based on observational data riddled with confounders, and there is plenty of equally compelling observational data that speaks against them, such as the fact that nut intake correlates strongly with decreased heart disease risk, even though nuts are a major source of omega-6.

        And like I said before, taking 4 grams per day of omega-3 will take the average American from a 10:1 to a 3:1 o6:o3 ratio, so saying that the difference that can be induced with supplements is only marginal is patently wrong. Even the high dose supplement studies, which meaningfully change the ratio, do not show benefit on cardiovascular outcomes.

      5. It is a great difference between reserch in food and drugs in that food has general effects that in each case are different in different contects while drugs are supposed to have specific (and therefore measureble) effects.

  21. I’m flabbergasted. No mention of the Omega-6 to Omega-3 ratio. That ratio defines the Omega-3 deficiency. The natural ratio is 1:1. Ratios above 4:1 are associated with numerous chronic diseases. Most Americans are up around 12:1 to 15:1. So, just taking some Omega-3 or eating fish once a week is a worthless exercise unless one cuts out the consumption of Omega-6 foods and takes other measures (take supplements) to lower their ratio. There are thousands of totally worthless Omega-3 tests. They are worthless because they do not measure to see if the Omega-3 deficiency is being addressed in the study. Consequently, a study based on worthless studies has a worthless conclusion.

    People who lower their ratios to 2:1 or less show good results in terms of heart health. Now, prove that statement to be false.

    1. To say I’m conflicted is not an argument. I can say you, as a medical doctor, are conflicted because you prefer drugs and operations. What does that do? I already know you understand some aspects of nutrition. But maybe you don’t understand lipid science as well as you think you do. That’s possible. I’ve been studying it for 22 years. I have more to learn I’m sure.
      As for my blog posts, ALL of them are footnoted to more qualified folks then me. Did you read my footnoted links. Most are by scientists that specialize in lipids.
      As for your 4 grams of Omega-3, do you take that much? Did the studies you refer to prescribe that much. Did any of them test for the ratios? Have you tested for the ratio in your example? If not, then how can you say how much change you’ll have? And if someone took 4 grams of Omega-3 supplements, for how many years did they keep it up? How many people participated? How many people were in the control group? How was heart health determined? How often were participants tested for the ratio? I could go on . . . but we’re just going around in circles. I have tested myself and made it public. I have participated in NIH studies that have measured folks and you can see them. There’s so much more. . .

  22. Would you like to see some attachments in that regard? I can’t just make talk and prove anything.
    For certain, your article did not prove anything because it didn’t address the definition of the deficiency.

      1. Promoting Omega-3, but Not the Ratio of Omega-6 to Omega-3

        Concerned About Heart Health?

        The second link has a link to my EFA ratio test results at the bottom of the article. I have maybe 40 more articles with attached studies I can send. But they focus on the ratio, not just taking some Omega-3.

        If after reading this, you might understand why I do what I do in meats and have the only store in the WORLD that sells Omega-3 chicken, Omega-3 turkey, and Omega-3 pork.

    1. The article showed that supplementing with omega 3 won’t make you live longer or decrease the number of coronary events you suffer. It didn’t make any claims about what would happen if you decrease intake of omega-6, which is a separate question. Increasing omega-3 intake with supplements will by definition lower the omega-6 to omega-3 ratio.

      1. An additional 2-4 grams per day of omega-3 versus 140 grams of total fat per day (United Kingdom) and at a 1:9 omega-3:omega-6 ratio. Did you really expect any effect?

      2. Even if you think it’s the ratio that matters rather than the amount, 4 grams of omega-3 per day would take the average American from a 10:1 to a 3:1 ratio, so the change in ratio is hardly inconsequential.

    1. “Most people consume so much Omega-6 that a tiny Omega-3 supplement has no bearing on the ratio.” — Ted Slanker

      So you’re basically affirming Dr. Rushworth’s conclusion that adding fish oil or other omega-3 supplements does not lower the number or severity of cardiovascular events nor reduce mortality. That was the question/hypothesis of his article.

      Your banging a drum about omega-6 and the omega-6:omega-3 ratio is a different question. You suggest that the high ratio of omega-6 to omega-3 is responsible for adverse effects: “Ratios above 4:1 are associated with numerous chronic diseases.” Please cite the studies that prove your hypothesis. The ones you link on your “Grass-Fed Beef” promo page don’t prove that.

      A study linked on your promo page by A.P. Simopoulos, “The importance of the ratio of omega-6/omega-3 essential fatty acids,” takes a shot at demonstrating that in Table 9, “Ethnic differences in fatty acid concentrations in thrombocyte phospholipids and percentage of all deaths from cardiovascular disease.” Unfortunately, it only demonstrates the correlation between higher AA:EPA ratios in various populations and mortality from cardiovascular events in those populations. Correlation does not prove causation. Indeed, the 4th bullet point in his Conclusions talks only about the correlation, not causation.

      Fortunately, another paper in Am J Clin Nutr by the same author, “Omega-3 fatty acids in health and disease and in growth and development,” cites actual studies. After the obligatory discussion of man’s evolutionary diet vs. current diet, his 1991 paper reviewed 1541 studies (approximately 250 human) of omega-3 fatty acids in the years including 1984 to 1989 (Fig. 1). But instead of sticking strictly to “health, disease, growth, and development,” as the title of his paper suggests, he first launches into sources of fatty acids, the evolution of the EFA balance, the production of vegetable oils in agribusiness, and other non-medical topics.

      Seven pages later, he finally abandons the discussion of the omega6:omega-3 ratio gets into the metabolism of the EFA and their effect on humans, specifically, omega-3’s “hypolipidemic, antiatheromatous, anti-inflammatory, antithrombotic, vascular, and other effects.” Each of these effects are summarized in turn:
      • Hypolipidemic: In patients with type IIa hyperlipidemia, dietary omega-3 fatty acids did not change total or LDL cholesterol, slightly increased HDL, and lowered triglyceride concentrations.
      • Antiatheromatous: There were no human studies, but in dog, swine, and two primate species, fish oils were found to have antiatherogenic effects [inhibited hardening of the arteries] even if they did not lower serum lipids.
      • Anti-inflammatory: Many experimental studies have provided evidence that incorporation of alternative fatty acids into tissues may modify inflammatory and immune reactions and that omega-3 fatty acids in particular are potential therapeutic agents for inflammatory diseases.
      • Antithrombotic: There is no evidence that the increase in bleeding time is clinically significant or has any adverse effects.
      • Vascular: Omega-3 fatty acids … increase endothelium-derived relaxing factor (EDRF). EDRF presumably contributes to antithrombotic and antiatherosclerotic effects of omega-3 fatty acids by relaxing vascular smooth muscle and inhibiting platelet aggregation.
      •Antiarrhythmic: A modest intake of fatty fish two-to-three times per week (or 3 g fish oils/d) reduced all-cause mortality by 29% over a 2-y period, possibly by preventing sudden death from arrhythmia.
      • Restenosis (a re-closing of blood vessels opened by angioplasty): The role of omega-3 fatty acids in the prevention of early restenosis after coronary angioplasty is a major area of research because percutaneous transluminal coronary angioplasty is an important treatment for selected patients with CHD.

      Simopoulos also discussed the use of omega-3 fatty acids in the treatment of coronary heart disease (CHD), hypertension, cancer, diabetes, and autoimmune disorders like arthritis, psoriasis, and ulcerative colitis. In Conclusions he returned to a discussion of omega-6, which was not part of his study.


      So while the positive health effects of fish oil and other omega-3 fatty acids can be demonstrated by this second study, it does not prove a reduction in heart disease or mortality, which was Dr. Rushworth’s hypothesis. Nor can it be used to bang a drum about omega-6 causing “numerous chronic diseases.”

      1. Simopoulos is a woman.

        Sebastian’s review proved nothing because it had nothing to do with the EFA ratio. Scientists who specialize in the study of fats look to the EFA ratio to determine the Omega-3 deficiency. The whole point of discussing Omega-3 supplementation is to determine if there is a deficiency to begin with and at what point is there no longer a deficiency. Isn’t that right? Makes sense to me.

        To date, there are no long-term studies of groups being tested with high EFA ratios versus low ratios in the conventional study context. Some have been attempted but were stopped early because outcomes were different and continuing wasn’t ethical. As with nearly all observations regarding diets, I doubt a passable study could be properly performed. But there are thousands of anecdotal results to view and discuss in addition to the anthropological studies of various populations. Both approaches support the EFA ratio “theory.” I am a good example.

        “Everyone” in “medicine” is looking for studies on diets like they are performed on drugs and operations. But that’s like herding cats. Diet studies must be over many years. Unless you lock up your groups and ONLY allow them to eat what you’re testing, you will never get a valid study. I’ve been involved in two short-term tests conducted by the NIH where they did highly restricted studies with military troops. I refer to both tests at the end of the first paragraph in this link.

        Sometimes it’s the anecdotal and anthropological observations that are most important. For an instance of anecdotal outcomes, diabetics who do the “keto-type” approach and eat lots of meat and animal fats stop their diabetes within a couple of weeks. People can stop asthma, arthritis, MS, and many more “incurable” chronic diseases as their ratios plunge. They do it by avoiding carbs, avoiding foods with sugar such as fruit, avoiding foods high in Omega-6 fatty acids, and by eating the grass-fed and Omega-3 meats and green leafy vegetables.

        It takes a lot of willpower to make it happen, but of the people who do it, the success rate is extremely high. It’s way too high to ignore. But the medical community ignores it because nobody can make any money from the cure. Even I won’t make more money if the entire population switched to eating proper foods. That’s because farmers and ranchers would raise different crops and all grocery stores would sell different goods. Everyone’s cash flow in the food business would remain the same except for the medical industry which would no longer be getting 18% of the nation’ GDP. In the process, why would folks continue to buy online when everything they needed was just down the street at their grocery store they always went to. It’s the old tale . . . follow the money.

  23. Restatement of unfinished sentence.
    Changing a ratio from 15:1 to 14:1 can’t measure any kind of improvement in health and disease. Especially if heart health requires a ratio down around 2:1 or less.

  24. As for Omega-6. I’m not interested in eliminating it, just balancing it with the other EFA. Omega-6 is essential too. But in excess (of Omega-3) it leads to inflammation.

  25. Ted had a partial point above. Most likely the study subjects had a diet with way too much pufa-6. If you ADD omega-3 to this, maybe it is not enough. The enzymatic pathway for both is still being dominated by pufa-6. These omegas are signalling and structural molecules, who told us to consume them as energy molecules? Or in general in abundance, creating havoc with oxidative derivatives (4-hne, hhe etc).
    You should as per Ted cut back omega-6 and increase omega-3; changing two variables at the same time. Would speculate that cutting omega-6 back is alone satisfactory. Any fat you consume, there are all fat variables present.
    As always, fish and meat in moderation have done the trick to our ancestors.

  26. O3 should have some benefit against covid as a blood thinner. But aspirin and NAC also work well for that. No need for Heparin. The FDA just took NAC off Amazon, apparently because it works well against covid, cutting into pharma profits.

  27. In the link below, in the middle of the page somewhere) is a link to my Omega-3 test. The test directly references heart health. Both my parents (and their parents) had heart issues and were on medications. I’m 76 now and take no medications. Zero.

    So far, I’m doing much better than they did and my mother followed the USDA dietary recommendations religiously. The government’s recommendations date back over 100 years and include many myths and nonsense which cause disease. In my mother’s case the MyPlate type diet literally killed her. She had no idea she had had a son when she died. The government seems to like the idea that 18% of the GNP goes to healthcare.

  28. This is why reducing the consumption of foods that are high in Omega-6 is so important. For 2.5 million years man was an apex predator. His diet was mostly meat and the natural EFA balance of his game would be similar to grass-fed beef. That’s about 1:1. He also ate fish. Other than that he ate virtually no fruit, very few tubers, few nuts, but some green leafy plant material. Green leaves are the primary sources of the proper balance of EFAs for the animal kingdom (in the sea and on land). Only after inventing farming did man dramatically change the balance of his EFA consumption. This is why when farmed foods were introduced to populations that lived more off the land (so to speak) their chronic disease case rates soared. EFA = essential fatty acids and there are two families of fatty acids called Omega-6s and Omega-3s.

  29. Thanks for more interesting science Sebastian. We are all biased people, and I think that is why you see people being for the scientific method when it is proving their believes, but against it when it disproves it. It is very hard to just let the studies and numbers be like they are, without biases.

    With that said, my personal ideas about how our bodies work, without being a doctor or researcher, or really having studies health much at all, is that adding more things in the form of pills will never make up for a bad lifestyle. It doesn’t matter if the pills are called medicine or if they are called supplements, if you live on fast food, sleep to little and live a stressful life, and so on, a few pills will not improve your health.

    I wonder if there is really much use to studying health with double blind studies where half the group gets a pill and the other half gets placebo. From what I’ve seen you go through on this blog, statins doesn’t show any real effect, omega 3 doesn’t have any real effect, vitamin C doesn’t have any real effect, etc. Is it possible to do other studies, perhaps when you try to figure out how the body works? Instead of looking at it like a black box that you change the input to and then read the output, you change the input and then measure things internally? If you give 100 people omega 3 supplements, does the amount of omega 3 in their blood (does it show in the blood?) increase? If you measure the omega 3 levels of people with different diets, is there a difference? If you measure more variables than just omega 3, does different diets show different values? If you have the same diets, but different populations, does the values change? Are there changes to the gut flora of people with different diets?

    Tests like this could give an idea of how our bodies work and how it should look when it is running well. Then doctors and health care providers could try different things with individual patients to try to move to more optimal health.

    1. Staffan,
      good idea. If you take this to a personal level – just measure your Vit.D, Omega-Quotient and many more. If the level of an essential substance in your body is low -change your diet or take a supplement.

      1. That’s pretty much the only way to do it as an individual. It doesn’t help me if I feel like crap but my doctor tells me I should be healthy, or if large studies show that I’m inside of all norms. Many people today are also not healthy, so the “normal” values are not what you should aim for. It gets easier if you manage to find doctors that are thinking instead of just following the currently approved manual though.

    2. There are tests and they’ve been around for over 50 years. But medical doctors very rarely if ever request an EFA test. I’ve been doing business with Doug Bibus for a long, long time. He performs them by the thousands. What’s amazing is that many animal feed companies are formulating pet foods that have low EFA ratios because the pets end up much healthier and live longer with fewer health issues. Dogs can cure their diabetes, skin issues, and on and on by eating those feeds.

  30. I have been of the belief that Om3 is an anti-inflammatory and, if so, would show some signs of improving morbidity data? Hmm Stuff is not cheap and the impact on the oceanic food chain is said to be progressively devastating, sooo. Thanks for this, Sebastian. Gonna save me some money.

  31. Does it matter? Life expectancy for Inuits is somewhere between 67 and 69 years, which is much lower than in the Western world.
    When it comes to cardiovascular deseases then it’s not so much wrong diet that causes them but obesity, smoking, lack of excercise, sleep patterns, stress, noise pollution etc.

    1. The Intuits stopped eating their traditional diet long ago which is why they are as sick as everyone else. So that makes them normal and everyone blames their sicknesses on something other than diet. There is so much literature around on this that it’s somewhat crazy these comments are being made. Search for it and you’ll see what I mean. The literature goes back to around 1900. And what happened to the Intuits is the same thing that happened to the American Indians when they started eating the modern, USDA-recommended “balanced” diet of farmed foods. Americans Indians didn’t used to be fat with diabetes and heart disease. But many are now. They used to eat a lot of grass-fed game and had low EFA ratios. But no more. And I can say the same thing for African Americans. Many of them came from meat-based diets. Their ancestors were healthy when they were in Africa. But not the same here.

  32. I started taking cold liver oil capsules and garlic tablets around 20 yrs ago as I got flu nearly every year [I worked outdoors] since taking these I have not had flu.
    I also take Turmeric as an anti inflammatory for arthritis instead of Naproxen of which I would have to take 2 tablets a day , Turmeric I take 1 capsule every other day for the same results
    I also take Glucosomine and Green Lipped Mussel.
    Did any of these supplements work? [apart from Turmeric]I never knew until I had to stop taking them all for 2.5 weeks before going for a hip replacement, first week without, no difference but the 2nd week pain hit like a hammer

  33. I once had an episode of badly inflamed joints, started small and worsened to the point where I thought I would need to be med-evaced from the oil rig I was working on. Finally I decided to try the cod liver oil capsules I’d taken out with me. The improvement was pretty dramatic and two weeks later I was able to walk 14miles. I later got a provisional diagnosis of Sarcoidosis. Could have been placebo I suppose, though the fact that I’d just sat on those capsules for 10days suggests I didn’t have any great faith in fish oil.

  34. “Increasing intake of omega-3 does not protect against heart disease.”

    While this is the conclusion of Dr. Rushworth’s review of specific studies, I believe that actually, his review only finds that omega-3 does not prevent death from heart disease. There were no studies that looked at heart imaging or blood flow, etc. both before and after omega-3 use. So, I’m not sure the conclusion is valid. There are various ways omega-3 can be beneficial, such as lowering inflammation, as others above have commented. And, I’m not sure the time period of subject follow-up is long enough. Perhaps you need to have a diet high in omega-3 from foods sources (not supplements) from a young age on? We don’t know.

    Further, as others in this string have commented, it’s “garbage in, garbage out” you can’t take one preventive measure selectively or load up on one “super-nutrient”, while eating other harmful nutrients, and expect to achieve the desired outcome. We also know nutrients act in multiplicative, synergistic, etc. ways.

    If your breaks are good but your tires are fair, have you really reduced your changes of a collision?

    At any rate, we know studies should look at benefits of fish consumption, not supplementation, which we already know does seem beneficial. there is a lot that remains to be studied over longer time periods.

  35. Thanks for the analysis Sebastian, but all that this proves to me is that all else being equal, taking Omega 3 supplements doesn’t really improve your health. That being said though, as you know a person’s health is far more complex than whether they take one supplement or not. I’m a big proponent of percision medicine and there may still be certain people who benefit from omega threes when taken in combination with other foods/supplements or lifestyle changes. This is also a randomized study, so it may have a lot of people who do not benefit at all from Omega three supplements because their levels are already adequate.

    1. What is adequate? Omega-3s play a huge roll in immune function, being noninflammatory, and more. There are good studies out there that show that improvements in those arenas occur with a lowering of the EFA ratio well below 4:1 to preferable lower than 2:1.

      Most people are experiencing body failures (chronic diseases) these days and having a chronic disease is so common it’s considered normal. Is a deficiency normal then just because everyone is like everyone else?

      There is no question that Omega-6s and Omega-3s are ESSENTIAL. Water is essential too, but too little water is a problem and too much can kill you. There are many scientists (biologists, anthropologists, nutritionists, endocrinologists) who have spent decades studying lipids and they think that they have determined what is and is not adequate in the EFAs. But this discussion ignores their work. Yet I assume everyone accepts the fact that bodies require adequate nutrition. And there is a big difference between adequate and optimal. One keeps you alive, if you have access to drugs and operations for chronic diseases, and the other keeps you alive without chronic diseases or at least very subdued symptoms.

      Here is a video ( where, at the two minute mark, Artemis Simopoulos actually explains why this thread has gone off the rails by her discussion about the failures of study methods. And that is why we can’t draw conclusions from improperly performed studies.

  36. Oh please Sebastian,
    don’t be hasty! In PUB Med there are about 3.000 articles on Omega-3 and the findings are different, I totally agree. But Omega-3 fatty acids have a positive effect on heart attack, both in preventing them and in treatment. Please consider that 3 things are most important: most studies dont measure the Omega-3 status (Omega-3 index and or ratio Omega-6/3) before and after – so what are they looking for? The qualitiy of the oil used is often not described – ethylester or triglycerid? How high was the dosage? – Under 1g/day there is no effect, with 2g/day there is significant effect! And, last not least, how long did people take the EPA/DHA? Generally it has to be done for 3 to 4 month. Probaly you eat fish and therefore your stock of Omega-3 is quite ok , but fish from farms have only half the Omega-3 level they had about a decade ago and processed food is very high in Omega-6 (sunflower oil, fast food etc.), so imbalance is inevitable for most people. I am in Sweden now on holiday (nice! no maks, no panic!) but send you more stuff to study once I am back to Germany.

  37. Here’s a “Morning Letter” from Mark Sisson and his take on “studies.” He basically says what I’ve been trying to get across and what Dörte Schreinert is saying along with others in this thread. I’ve even posted links to my personal lipid analysis which focuses exactly on what Mark talks about. Here’s what Mark wrote:

    Morning, everyone.

    You know how they release those studies showing links between certain foods and heart disease, cancer, and early mortality? And everyone freaks out, and your coworker tags you on a Facebook post linking to some news report about it?

    Then you go read the study and realize that it’s based on Food Frequency Questionnaires, or FFQs, which ask people to remember what they ate weeks, months, even years ago.

    There’s a better version of those studies: red blood cell fatty acid analyses.

    Rather than ask people what they ate and force them to try to remember their weekly menu from months back, in RBC-FA studies they measure red blood cell fatty acid concentrations and plot them against health outcomes.

    The cool thing about RBC fatty acid measurements is that they are objective. You can’t lie about them. You can’t forget them. They simply are, and then you measure them and get the answer.

    Another cool thing about RBC fatty acids is that they reflect what people eat. Not always directly—some fatty acids make it into red blood cells in a roundabout manner—but often the fatty acids you eat show up directly in the RBCs. And even when it’s indirect, when the fatty acid in your RBC doesn’t come from the fatty acid you eat, you can still estimate what people did to achieve that FA concentration.

    So let’s look at the latest study to come out using RBC fatty acids. This time, they looked at how these fatty acids were related to a person’s risk of mortality. Which fatty acids in the red blood cells did they look at?

    They looked at omega-3 index, which measures the percentage of RBC fatty acids that are omega-3. The more fatty fish and other sources of omega-3s you eat, the higher your omega-3 index.

    They looked at myristic acid, a marker of dairy fat consumption. It’s also found in red meat and coconut fat.

    They looked at behenic acid, the best source of which is peanuts or macadamia nuts. But little is directly consumed. Most RBC behenic acid comes from the elongation of stearic acid that we’ve eaten (a saturated fat found in meat and cocoa fat).

    They looked at palmitoleic acid, which is actually a marker of de novo lipogenesis (the creation of fat from excess carbohydrate intake and an over-burdened liver).

    What happened?

    Higher omega-3 index (higher omega-3 intake, more fish consumption) meant a longer life.

    More myristic acid (more dairy, meat, coconut consumption) meant a longer life.

    More behenic acid (either more peanuts and mac nuts, but probably more stearic acid from meat and chocolate) meant a longer life.

    More palmitoleic acid (from too many carbs and an overwhelmed liver creating fat from said carbs) meant a shorter life.

    That still doesn’t prove causation, but it’s way more interesting than one of those studies using Food Frequency Questionnaire data.

    Do you still get worried when you read those FFQ studies? Does a study like this one make you feel any better?

    Mark Sisson

  38. Hello Dr Rushworth,

    I have just finished your book on Covid and found it a breath of fresh air. I need to read again and continue my own research as well but to find someone with credentials, not on any fringe and speak so plainly and concisely about Covid was so good to read. Many thanks.

    As far as your take on Omega 3s, please review the data from the VITAL TRIAL from the U.S. Quite interesting to say the least. Not well known for some reason but one of the largest gold standard trials. I would also recommend OmegaQuant as a resource you may not have seen. William Harris is one of the giants in this research as well as his friend, German cardiologist, Clemens von Schacky.

    All so interesting for sure.

    All the very best,

    Tom Dolan
    Burgos, Spain

  39. Dear Sebastian,

    Forgive me for the informality in my salutation but as I have read your book and follow many of your Covid posts, I thought you wouldn t mind.

    As an armchair researcher for many years and an ardent suppporter of the Omega 3 issue, I was a bit surprised on your take as your article progressed. As you may know, many of the early studies did not (and many still do not) measure the Omega 3 Index in participants before and after the trials. Also, we must bear in mind the effect of the new medications that many people in these trials are on, on top of the Omega 3 supplements given. Many of these are anti-coagulants and it has been pointed out by William Harris that these conditions will skew the results of these trials. One more thing would be to review carefully the seconday endpoints of the VITAL Trial, which is one of the most comprehensive recent trials on Omega 3 and Vitamin D. Well done and researched. These reults may change your mind on your ideas. Also, take a look at William Harris´s work. He is brilliant and developed, along with a German cardiologist, Clemens von Schackey, the ever, more and more respected Omega 3 Index.

    All the best and keep up the good work,

    Tom Dolan
    Burgos, Spain

    1. Many thanks for sending me this but as much as I respect and have enjoyed and used Sebastian´s interesting take on a variety of issues, I do believe he is way off base on the Omegas. My comments are at the bottom of the article and this is to briefly state them again. Simply look at the VITAL Study and also the work of William Harris. The understanding of the Omega Index is the key to the very posiitive outcomes I feel.

      All the best,

      Tom Dolan

  40. Unless the RATIO of the Omega-6 to Omega-3 essential fatty acids is the focus, then the entire Omega-3 discussion is off the rails. A ratio in excess of 4:1 is associated with increasing incidences of chronic diseases. Ratios of 2:1 or slightly less are associated with low inflammation and good health. Most Americans are 15:1. It’s no wonder 18% of the GNP is for medical care. Prior to the invention of agricultural, when eating on the wild side man’s ratio was usually less than 2:1. So that’s where his body wants the ratio to be today.

Leave a Reply

Your email address will not be published. Required fields are marked *