Tests find many popular omega 3 supplements are rancid


97 points | by clumsysmurf 310 days ago


  • terr-dav 310 days ago
    > The researchers found a total of 45% of flavored and unflavored supplements tested positive for rancidity, with 32% of flavored supplements testing positive and 13% of unflavored pills.

    They added percentages of two separate groups to get the total rate of rancidity. Seems like the overall rate of rancidness is roughly 1/4, not 45%. Makes me think either 1) this was not written by a human or 2) the human who wrote this made a pretty egregious error.

    Overall takeaway is: don't buy flavored omega-3 supplements.

    • dsugarman 310 days ago
      From the actual paper, it looks like what they did was worse than just adding the two and the article is nonsensical

      >Overall, our results revealed that 68% (23/34) of flavored and 13% (5/38) unflavored consumer Ω3 supplements exceeded the TOTOX upper limit set by the Global Organization for EPA and DHA (GOED) voluntary monograph standard of ≤ 26, with 65% (22/34) flavored supplements and 32% (12/38) unflavored supplements failing the PV upper limit of ≤ 5 and 62% (21/34) flavored supplements exceeding the p-AV upper limit of ≤ 20.

  • s0rce 310 days ago
    Olive oil is also frequently rancid. I frequently find packaged nuts and trail mix routinely rancid.
    • zactato 310 days ago
      Sesame oil is the worst. It has a shelf-life of a week or two.
      • tomjakubowski 310 days ago
        I've been using the same bottle of toasted sesame oil for at least two years now with no ill effects
        • fsckboy 309 days ago
          oil rancidity doesn't cause ill effects in general, just off smells and taste. Which, if you don't notice, is fine, the more things taste good to one, the better off one is.
        • ratsmack 310 days ago
          I keep mine refrigerated.
      • adasdasdas 310 days ago
        What kind of sesame oil are you getting...
      • CreepGin 310 days ago
        I think unopened sesame oil can have years of shelf-life. I certainly never had a problem with the smell and we use sesame oil quite a bit in our household.
        • etrautmann 309 days ago
          Same for me - I’m quite sensitive to rancid oil and have never experienced an issue with any brand of sesame oil kept unrefrigerated for a long period of time.
      • chriskanan 309 days ago
        Refrigerate it and the shelf life after opening increases greatly.
    • bjoli 309 days ago
      Rapeseed oil is what I use. It can be kept in the fridge, and from what I manage to read online there are no real benefits of olive oil over it except maybe taste and vitamin e content, and people claiming otherwise seem to never really be able to back up their claims.

      It works just as well except when you want the taste of olive oil. I find it superior when I stir fry things since the smoke point is higher.

    • specialist 310 days ago
      I now taste test most everything.

      One challenge is not knowing how something should taste.

      I once got harvest fresh olive oil (as a gift). Wow! Total game changer.

      ~TLDR~ FYI: The good stuff should make you cough a little bit after you swallow it.

      • reciprocity 310 days ago
        Three sentences with a "tl;dr" at the end?
        • samtho 310 days ago
          Attentions spans are getting very… wait what was I doing?
        • amenhotep 310 days ago
          Also the tldr is new information not a summary of or even present in the ostensibly too long text!
        • SkyPuncher 310 days ago
          I don’t think that’s uncommon.
    • mkoubaa 310 days ago
      If you're in the US, I recommend the terra delyssa brand for olive oil (many grocery stores carry it)
      • colechristensen 310 days ago
        I’d rather recommended only buying bottles of olive oil with printed harvest dates on the bottle within the last year. It’s absurd that stores are selling two year old oil. There’s a real problem with grocery stores having too many options for a single product and then most of the product on the shelves is unacceptably old.

        See also: coffee.

        We could have better food with fewer preservatives and less processing if the supply chain would pay attention to this problem.

        • etrautmann 309 days ago
          It’s absurd that most coffee, even high end beans, is sold with only a use by date (often a year or more after roasting).
          • plorkyeran 309 days ago
            If you buy directly from a roaster they'll always tell you the roasting date, but most supermarkets actively forbid them from putting that on the bags sold there.
            • mgarfias 309 days ago
              I solve for this by roasting my own
  • kleton 310 days ago
    Abstract doesn't mention anything about tocopherols (vitamin e) that is frequently added to these oils as an antioxidant. Would these be expected to be effective at scavenging oxygen from the capsules?
  • oarfish 309 days ago
    Another reason to avoid random supplements. Most people don't benefit from Omega supplementation. Add the risk of contamination and increased chance of afib ... the supplement industry really has successfully brainwashed the public into ingesting all kinds of substances without clinically validates effect.
    • mgarfias 309 days ago
      What is this risk of afib you talk about?
  • mckirk 310 days ago
    If you are in the EU, I can wholeheartedly recommend omega3zone[1]. Their fish oil actually tastes pretty nice and absolutely not like fish, keeps in the fridge for quite a while and has insane concentrations of the 'good stuff' (EPA and DHA in triglyceride-form). It is admittedly expensive (though you can dose it way lower than they recommend, given how concentrated it is), but to me it's worth it.

    [1]: https://omega3zone.de/products/omega-3-fischol-500ml

  • DoreenMichele 310 days ago
    The researchers found a total of 45% of flavored and unflavored supplements tested positive for rancidity, with 32% of flavored supplements testing positive and 13% of unflavored pills.

    The above math looks wonky to me but fits with the TLDR at the end of the piece:

    Both Frame and Hands suggest exercising caution with flavored fish oil supplements at this point due to the uncertainty of how the flavoring may affect their freshness and, thus, any potential health benefits.

    • tyleo 310 days ago
      I feel like this is an example of reporting on a paper misunderstanding some of the details. Specifically that probabilities can’t simply be added together.
      • justinclift 310 days ago
        May not have been a human writing it. :/
  • EpiMath 310 days ago
    $62 to access the paper
  • grooverider 310 days ago
    Note, even the "good" brand can go rancid if you don't take care of your stash. I highly recommend cutting one open for a smell test if you're unsure. Also, if you're getting gross burps, your batch may be bad.

    I've used Aqua Omega (unaffiliated) with great success for years.

  • xwdv 310 days ago
    It’s probably best to take your omega 3 in liquid form rather than capsules.
    • riffic 310 days ago
      best is from dietary sources.
      • kleton 310 days ago
        Dietary sources are not vacuum-distilled for removal of heavy metals and microplastics.
        • brutusborn 310 days ago
          Does vacuum-distilling foods have a special name?

          I’m skeptical that it can remove heavy metals but can’t find any info.

      • xwdv 310 days ago
        You have any idea how much salmon you’d have to eat? Supplements are more concentrated.
        • opportune 310 days ago
          You don’t have to eat that much salmon, just a typical 5oz serving 2-3 times a week? And it doesn’t have to be salmon either, you can get DHA and EPA from Sardines, Oysters, Mackerel, Herring, Trout, Anchovies…
          • TylerE 310 days ago
            I would be shocked if the average person eats salmon 2 or 3 times a year.
            • defrost 310 days ago
              We eat Kimberley Barramundi every week - slighly over two thirds of the protein + omega 3 per unit of wild salmon .. but much cheaper as we catch most of it ourselves and freeze it for later.

              Salmon's not a local fish here being the main reason - and catching Barra makes for time well spent outdoors.

            • smileysteve 310 days ago
              I went to Alaska and ate Salmon almost every day for 2 weeks.

              I probably eat salmon once every other week.

              There's a mail order fish company that would love for you to eat more salmon.

            • mkoubaa 310 days ago
              Depends on where you live I imagine
        • riffic 310 days ago
          eat your greens
          • DoreenMichele 310 days ago
            That's news to me. I previously heard flax seed and walnuts were the only good vegeterian sources of omega 3.

            A quick search agrees that greens, like spinach, broccoli and cabbage, do contain small quantities of omega 3. I'm having trouble getting a clear idea here of how helpful they are in comparison to the standard recommendation of fish oil.

            Anyone have any good sources of info on how to get enough omega three from vegetarian sources?

            • astrange 310 days ago
              It's unclear if it's bioavailable from those sources at all. There's two forms ALA and DHA; the first is found from nuts and the second from algae. The fish get it from the algae.

              IIRC there is some evidence that ALA is only bioavailable for women and not for men, but I don't remember if that's reliable.

              • DoreenMichele 310 days ago
                I had heard that flax seed may not be bioavailable. Walnuts are my go to as the only vegetarian source I understand to have substantial amounts of bioavailable omega 3.

                Would love to get a clearer idea of how much I really need and how much produce I consume may be defraying that number.

                • derbOac 310 days ago
                  It's difficult to find EPA or DHA from vegetarian sources (other than algal oil), although ALA is easier (e.g., walnuts, flax, chia).

                  Camelina oil is another good source of ALA if you can find human-grade versions of it. I thought it was nice as a sort of alternative to olive oil raw (like served with bread, or maybe tossed in cold salads), although it had its own flavor (sort of a grassy flax-like flavor), and is impossible to find now it seems. It wasn't something I would probably use a lot of but had a solid niche.

                  At one point there was some interest in transgenic camelina oil because it was easily converted into varieties expressing EPA and DHA. For example:


                  I've never seen that sold anywhere though.

            • caiomassan 310 days ago
          • nomel 310 days ago
            One cup of Kale provides a 121 mg of omega-3 fatty acids. I would need 13 cups a day. The recommendation should be "eat your nuts and legumes", if you want to stay away from meat.
            • xwdv 309 days ago
              Vegetables are an inefficient delivery mechanism for most nutrients, you have to eat huge quantities to meet quotas. I don’t see the point of them.
    • kleton 310 days ago
      Wouldn't the capsule provide an additional barrier to oxygen, ceteris paribus?
      • FriedPickles 310 days ago
        Maybe. But with the liquid form, you can smell and taste when it's rancid. You could take a whole bottleful of capsules and have no idea they've gone bad.
        • kleton 310 days ago
          Ah, I pop them in my mouth for QC but I might just be weird.
  • pengaru 310 days ago
    Just eat canned sardines in water, drink the juice. It's an excellent source of omega-3s and protein.
    • colordrops 309 days ago
      Sardines can have a lot of arsenic. Also, for those of us that are vegan, they are not an option.
  • curious_soul 310 days ago
    Slightly off-topic, but does anyone here notice a positive difference from omega 3 supplementation?
    • TjZkxkxeky 310 days ago
      I haven't died of cardiovascular disease this week!
    • mgarfias 309 days ago
      So I was prescribed vascepa to lower my triglycerides. They’re now low enough that I was taken off them.

      But I’ve also significantly cut down on the calories I’ve been eating.

  • MaintenanceMode 310 days ago
    That’s so gross. Ick. Great finding. I’ve actually wondered about this in the past.
  • elhudy 310 days ago
    Does anyone here have access to the list of rancid brands and can they post it?
    • tourmalinetaco 310 days ago
      It’s majority flavored are rancid, so just go unflavored and you have an 87% chance of being fine.
      • lacrimacida 310 days ago
        Just curious. Are the rancid ones bad for ones health or ineffective in any way?
        • water-data-dude 310 days ago
          I’ve read in a few places that it’s bad for you, but I’ve not done a deep dive and formed an “I’m confident” level of knowledge. The wikipedia article suggests that it might be bad, but there’s not a lot of research on it.


        • Insanity 310 days ago
          Seems like the claim is they are less effective but not actively harmful. But don’t have access to the full paper.
  • caiomassan 310 days ago
    on the peter attia podcast, rhonda patrick said omega 3 should be on the fridge. https://www.youtube.com/watch?v=zkp0DRUQ33g
    • somedude895 309 days ago
      I keep them in the freezer and haven't had a fish oil burp since.
    • specialist 310 days ago
      Upvoted. I've been doing this. Glad to be validated.

      (Also, Dr Patrick is the best.)

  • Overtonwindow 310 days ago
    Dietary supplements in America are very loosely regulated. The law that governs this is the Dietary Health Supplements Act. Tl;dr DSHEA classified dietary supplements as a food or food product which the FDA classifies as "generally recognized as safe." (GRAS)

    It also said that so long as a manufacturer is using a vitamin, mineral, or dietary substance that was available before 1994 then are ok to manufacturer and it would be considered safe (GRAS.)

    There are additional requirements about manufacturing processes available before and after that date but that is the gist.

    The problem with this law is that supplements are not required to undergo any kind of testing or validation. If a dietary supplement causes a problem, the FDA does not really have the authority to order a recall. Instead it has to depend on the Federal Trade Commission, which can order a recall and levy sanctions due to mislabeling.

    Anyone can manufacture and sell a dietary supplements and sell them to anyone, there are no age restrictions. It's something that IMO needs greater oversight.

    DSHEA: https://ods.od.nih.gov/About/DSHEA_Wording.aspx

    General Recognized as Safe: https://ask.usda.gov/s/article/What-are-Generally-Recognized...

    FTC and FDA: https://www.ftc.gov/news-events/news/speeches/ftc-dietary-su...

    Congressional Research Service, 2021: "Regulation of Dietary Supplements" https://sgp.fas.org/crs/misc/R43062.pdf

  • tyleo 310 days ago
    I hate that the actual paper is behind a huge ($100+) paywall and the article doesn’t call out any brands. I take an Omega 3 supplement and want to know if mine is rancid :p
    • babyshake 310 days ago
      Same here. Assuming this is the case for fish oil capsules, even though you don't really taste the supplement itself?
      • tyleo 310 days ago
        The article specifically says < 15% rate of rancidity for pills which looks like it includes capsules since the only other category they call out is flavored supplements.
    • brutusborn 310 days ago
      I don’t think they’d want to name and shame as that attracts litigation.
    • thelastparadise 310 days ago
      It probably is.
      • tyleo 310 days ago
        I use unflavored pills. The article says those are rancid at a rate of < 15% so probably not.
  • ramesh31 310 days ago
    Supplements are easily the biggest single scam against consumers in existence. Just walked out of a CVS where I saw a large bottle of Vitamin C pills for $42. That's easily a 10,000% markup or more on the raw ascorbic acid in those pills. Not to even mention the lack of health benefits.
    • Overtonwindow 310 days ago
      It's like a lot of things: A lot of dietary supplements are scams, but a lot of them are legitimate. The core issue for people who take dietary supplements is that a) they probably don't need it, b) they may be taking too much, and c) unless they are getting a mineral and metabolic panel, etc. they have no idea if they even need the supplement.

      IMO before taking any supplements one should get a panel done to see if you even need it.

    • tyleo 310 days ago
      I don’t know. I buy caffeine pills, whey powder, and a few other supplements. They are certainly marked up but simultaneously the nest efficient way to get caffeine, protein, etc per dollar.
    • fragmede 310 days ago
      You think that's bad, just wait till you hear about bottled water! Or maybe it's a convenience thing and that's worth something to some people.
      • TylerE 310 days ago
        Do people really not get that you’re paying for the shipping, not the water?
    • mmh0000 310 days ago
      > "Just walked out of a CVS"

      Well, there's your problem. CVS and Walgreens are the two best places to go if you don't care about your money. Otherwise, at a grocer, Walmart, or Amazon, a bottle of a decent brand of VitC can be had for $7.5.

    • ryanklee 310 days ago
      Depends on the supplement.