Doctor's Note

For some of the latest videos about plant-based omega 3s:
PCBs in Children’s Fish Oil Supplements
Flaxseeds For Sensitive Skin (EPA not DHA)

And for some of the most recent videos on fish pathogens:
Zero Tolerance to Acceptable Risk
Tongue Worm in Human Eye
Allergenic Fish Worms

Because even distilled fish oil has been found to contain toxic industrial pollutants, the safest source is algae or yeast derived EPA/DHA (our bodies can retroconvert DHA into EPA and vice-versa). See some of my reasoning here. My recommendation is to ideally get 250 to 500 mg a day

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  • Veguyan

    Dr. Dave Woynarowski apparently has his own brand of fish oil supplements, and he spoke on the Longevity Now Conference with David Wolfe. His source for his product is line-caught mackerel. He says that plant sourced ALA is not very bioactive and does not convert well to DHA, maybe 5% conversion. Says flax is good but most nuts and seeds and plant-based omega 3s are more omega 6 than 3 and you need more 3 than 6 to blunt the inflammatory aspects of the 6. Algae oil has way more DHA than EPA and we need both, actually need 3-1 EPA to DHA. Plant-based eaters need 125 g Omega 3 (per day, I guess) and they cannot get enough from Algae. Yeast technology that promises EPA is GMO and owned by Monsanto.

    Bottom line: We gotta get his product. Only his product will give us what we need.

    I’m using Vegan DHA by Minami Nutrition. I guess it’s useless, as it’s only 300 mg per day and I need 125 g, and it does not provide me with EPA. Too bad. I was getting such a nice placebo effect until I listened to Woynarowski.

    • Michael Greger M.D.

      I would certainly welcome any data Dr. Woynarowski has to offer, but what you ascribe to him doesn’t make sense to me. For example, the institute of Medicine has determined that the Adequate Intake for ALA is 1.1-1.6 g/day, 78 times smaller than what you recall him saying.

      Bottomline: Because even distilled fish oil has been found to contain toxic industrial pollutants, the safest source is algae or yeast derived EPA/DHA (our bodies can retroconvert DHA into EPA and vice-versa). See some of my reasoning here. My recommendation is to ideally get 250 to 500 mg a day.


        Good Afternoon Dr. G,

        Where would be the best place to purchase via online or walk-in the recommended Microalgae?

  • Veguyan

    Dr. Greger, thank you so very much for your availability and your response. It’s really great to be able to discuss these health questions with you. I’ve been taking the Vegan DHA for about a week, based upon this video you posted, and I really hope it is working for me. As a long term vegan of more than 35 years, who never really paid much attention to Omega 3s, I may very well be depleted and in need of this essential fat; I’ve certainly been battling depression all my life. And now between the magnesium and the DHA, whether by placebo or for real, I believe I am feeling better. I hope you know that I was being sarcastic when I wrote above that “we gotta get his product.”

    Thank you again.

  • GrantM77ni

    Dr. Greger,
    As you have reported, the effects of animal based omega-3 supplements can prove to be ironically, inflammatory. While you recommend utilizing algae as an alternative, is there concern over the neurotoxins (as you have discussed in other videos as present in spiralina and cholera), or are these only present in the blue-green algae?

    • Michael Greger M.D.

      All the algae-oil omega-3 supplements currently on the market are made from golden algae that don’t create the toxins that can be found in blue-green algae (such as spirulina, detailed here: Thanks for the great question, GRantM77ni.

  • Toxins

    I have the same question as Grant and arent walnuts and flax seeds good sources of DHA?

    • SArmstrong

      There is another video you might watch that answers this question (although the video is cut off at the end). See Essentially what Dr. Greger says is that while we can make DHA from the shorter chain omega 3 fatty acids in walnuts and flax, probably we can’t make enough from that route for OPTIMAL health.

  • sarahharmony

    thanks so much for this. great info – so helpful and much appreciated.

  • BPCveg

    Suppose someone wants to avoid having to buy this algae oil and is willing to each an ideal plant based diet. Is it possible? How many greens do you have to eat? What kind of a plant based diet provides the necessary 3:1 ratio of polyunsaturated fatty acids. Or is your video trying to imply that one cannot be healthy on a fully plant based diet without having to consume a algae oil supplement? I’m sure many vegans have been wondering about this point.

    • Toxins

      Hello BPCveg,

      I actually have an answer. Although this video says we need algae oil, I’m going to have to respectfully disagree with Dr. Greger. According to Dr. McDougall, “a condition of ‘essential fatty acid deficiency’ is essentially unknown in free-living populations….true essential fatty acid deficiency would result in: loss of hair, scaly dermatitis, capillary fragility, poor wound healing, increased susceptibility to infection, fatty liver, and growth retardation in infants and children.” Here is the full article Although the algae oil may have the DHA, oil is still oil and not a whole plant food. I respect Dr. Greger’s statement of avoiding fish oil for its many contaminants ,as seen here and using algae oil as a substitute but is it really necessary to ingest any pure DHA in the form of an oil? After weighing it out, to me, it doesn’t seem necessary.

      • BPCveg

        Thanks Toxins.

      • Michael Greger M.D.

        I don’t recommend long chain omega 3’s for deficiency; I recommend them for optimal health. To prevent scurvy, the vitamin C deficiency disease, you only need like 30mg of C a day. But no one would recommend only 30. The reason the RDA is more than double that is the recognition that the levels to avoid deficiency don’t necessarily mean that’s the level for optimal health. That’s like saying you just need enough D to avoid rickets. Not true–D does all sorts of wonderful things in the body besides keeping your bones calcified. Same thing with the omega 3’s. Do nonfish-eaters have to take long-chain omega 3’s? We don’t know. But the balance of evidence suggests it would be beneficial in my opinion.

  • Veguyan

    Dr. Greger, Is there a problem with Hexane extraction in the vegetarian DHA?

  • Gala Christen

    Not having a science background, I don’t know the difference between an algae or a yeast. We’ve been buying the algae-based DHA (Udo’s Choice DHA). I would like to be sure whether or not algae and yeast are the same. I don’t want to support Monsanto in any way. The Algae-based DHA isn’t GMO, is it? Algae and yeast-based DHA are 2 entirely different things, right?

    BTW, this pure form (not a blend of oil) DHA seems to be getting hard to find. Last time I checked my 1 local source, it was not on the shelf, and I just checked Amazon, I can’t find this product in the except in Canada. …Oh, no, now I just tried to buy it from the Canadian source and it’s not available there, either. Almost all that’s on the shelf is blends.

  • Jeremy Ayers

    I really want to do this (I’m epileptic and on the modified atkins diet) but my nutritionist tells me that the body doesn’t process the omega fatty acids as well when they are derived directly from plant based sources as they do from fish. Would very much like  your input on this (I was vegan before and wld like to be again but my seizures increased on that diet)

    • Toxins

      Firstly, you should drop the atkins diet, it is extremely harmful. Here is Dr. Gregers free e-book on the topic

      As for omega 3, your body converts omega 3 from plants (ALA) to DHA and EPA. Fish has already preformed DHA so your body does not need to convert it.

      ALA is not converted effectively to DHA under the condition that one
      is consuming too many omega 6 fatty acids. Since most whole plant foods
      contain good ratios of omega 6 : omega 3, this is of no concern unless one is eating a lot of nuts other than walnuts, flax seed and chia seed. The
      National Academy of Sciences does not recognize EPA and DHA as
      essential. This means there is enough evidence for them to conclude that
      we can make enough of it without eating it in its preformed state.

      In addition…

      Do vegetarians have to eat fish for optimal cardiovascular protection?1–3
      Am J Clin Nutr 2009;89(suppl):1S–5S.

      Interest in the cardiovascular protective effects of n–3 (omega-3)
      fatty acids has continued to evolve during the past 35 y since the
      original research describing the low cardiovascular event rate in
      Greenland Inuit was published by Dyerberg et al. Numerous in vitro
      experiments have shown that n–3 fatty acids may confer this benefit by
      several mechanisms: they are antiinflammatory, antithrombotic, and
      antiarrhythmic. The n–3 fatty acids that have received the most
      attention are those that are derived from a fish source; namely the
      longer-chain n–3 fatty acids eicosapentaenoic acid (EPA; 20:5n–3) and
      docosahexaenoic acid (DHA; 22:6n–3). More limited data are available on
      the cardiovascular effects of n–3 fatty acids derived from plants such
      as a-linolenic acid (ALA; 18:3n–3). Observational data suggest that
      diets rich in EPA, DHA, or ALA do reduce cardiovascular events,
      including myocardial infarction and sudden cardiac death; however,
      randomized controlled trial data are somewhat less clear. Several recent
      meta-analyses have suggested that dietary supplementation with EPA and
      DHA does not provide additive cardiovascular protection beyond standard
      care, but the heterogeneity of included studies may reduce the validity
      of their conclusions. No data exist on the potential therapeutic benefit
      of EPA, DHA, or ALA supplementation on those individuals who already
      consume a vegetarian diet. Overall, there is insufficient evidence to
      recommend n–3 fatty acid supplementation for the purposes of
      cardiovascular protection; however, ongoing studies such as the Alpha
      Omega Trial may provide further information.

    • drew

      did your doctors point to a reason for your seizures getting worse on a vegan diet?

  • Elin

    If you´re, like me, not so keen on eating supplements but still don´t want to eat fish to get your omega 3 is there any algae that you can consume like a food and not a pill? Is algae free from polutions we can find in fish? One of the reasons I don´t want to eat fish is all “the extras”.

    I googled golden algae, since I have not heard of it before, and I found that it produces toxins just like cyanobacteria does. But, if I remember correctly, you don´t recommend consuming cyanobacteria because of it´s toxicity. What makes golden algae okey to consume but not the cyanobacteria?

    • Gus Wehrman

      To give a for instance, I do know that the brand I happen to use, Ovega-3, sources theirs from “life’s DHA,” which they say is grown in certified stainless steel container outside of the ocean. This hopefully removes most of our concerns with the ocean derived varieties of this or that.

  • Kerry Rebecca Paterson

    I read an article a few years ago about promoting the growth of algae in the oceans to increase their CO2 absorption rates. Perhaps if we were farming more of this for the health benefits it would also have a noticeable positive effect on our planet.

  • cobalamin

    I tried DHA plant supplements and got nose bleeds and my brain felt like it was bleeding at a low intake level. Same thing when I use to eat fish.

    Everyone is different.

    • vegnurse

      I got nose bleeds too.

  • Shoshannah Sarah

    Why get algae in a supplement? Why not take the blue green algae as a food? That’s really the best.

  • Gus Wehrman

    Hello, Dr. Greger! I was having a friendly argument with a company rep who was (big surprise) touting the superiority of THEIR product in our supplements department. He dismissed the reality of retroconversion of DHA and EPA and attempted to trivialize the importance of significant levels of DHA above (get this) 5mg. Could you pass along the best scientific citation links that sum up the current consensus on these points? I’d love to have them on hand for future reference. Thanks!

  • rick

    I have read that ALA converts well to DHA when on a whole foods plant based diet. But does not when on the SAD diet. I guess this would mean that DHA supplement is good for those who eat a SAD diet but not necessary for those on a WFPB diet. Do I have this wrong?

  • Cyclesalone

    I am making my own almond milk. I drink a large glass per day. Am I getting enough Omega 3. How do I compensate for getting enough Omega 6. I’m new to all of this so please excuse my ignorance

    • Vickey

      Cyclesalone, almonds don’t contain any Omega 3’s, so you would need to add high Omega 3 foods to balance that. The ideal ratio is a range, not an exact number, as I understand it.

  • The English Coach

    Can I ask which one you personally use as it is difficult to weed through all the different ones on the market

  • Kar

    How do we know DHA plant based fatty acids,in supplements,are not oxidised? Fish and Krill oil supplements contain some type of antioxidant that ensures this.What about DHA supplements from algae?

  • Dg

    I ordered Deva vegan DHA EPA supplement and had to agree to prop 65 warning that the product contained cancer causing chemicals. Is this a cause for concern?

  • FitEyes

    I do recommend DHA in general.But I do not feel comfortable with the
    commercial vegetarian sources of DHA (even though I am a vegetarian). I
    believe Dr. Greger may have overlooked the genetic modification
    (mutagenesis) involved in the commercial production of DHA and EPA in
    microalgae, as well as the metabolic engineering, high processing and
    other unnatural production methods used. I provide more information at
    this link:

  • Han

    I can already hear them say: “Yes but that would make a lot of people unemployed.”

  • Stephen Albers

    Dear Dr. Greger,

    I am very appreciative of your addressing the Omega 3/6 ratio question. I have been following this research for a number of years. There appears to be solid support for the value of keeping this ratio in an an optimal range because it correlates to a long list of chronic diseases.

    There is one aspect of this question that you do not appear to address. There is a simple serum test that determines this ratio for anyone – gas chromatography, I believe. The test is available from a number of labs. My reading generates ambivalence about the test. Some writings state that accuracy is far more detailed than needed for clinical use. But other innuendos claim there are accuracy problems with the test.

    Do you support the use of the Omega 3/6 serum test to determine personal status?


    Stephen Albers

  • Teresa

    Neat video! Thanks for the info, and love the speaking up for our fellow animals!

    I’m guessing that the human ancestors (before they started hunting) got some of their Omega 3s from algae as well, through drinking water.

  • João Gabriel Varela Madureira

    Dear Dr. Greger : I have yesterday made a deep cut in my finger. I bled heavily and went through the ordeals of going through the chaotic health system of this country. The last doct, who stitched my wound commented that I was bleeding much more profusely than normal and that I had very thin blood. I answered that I was vegan and that I took omega3 supplements. I have since realized that I was taking too much flax seed. Instead of one tbsp I usually took two or three (I didn’t actually measure it but it’s my estimate). I also take a 100mg DHA supplement every week. Can you comment on these values and perhaps also some tips to recover lost nutrients ? (though I am feeling well and quite active).Thanks

    • Joseph Gonzales R.D.

      Thanks for sharing your story. My question is what did your doctor suggest? Sound like scaling back a bit on the DHA and/or flax seeds may be helpful. I know women who have experienced this shaving. If they have a small cut it tends to bleed more than when they were not taking DHA supplements.

      • João Gabriel Varela Madureira

        Dear Dr. Gonzales: thanks for replying. The doctor that cared for me didn’t make any suggestion. My question was more directed at the DHA consumption than the flaxseed consumption (which was a bit higher than recommended). I consume 100mg weekly, which is about 17 times lower than the recommended dose of 250 mg per day. I was actually wondering if I should consume more DHA to counteract the smaller dose of flaxseed I will be taking.

        • Joseph Gonzales R.D.

          I see. Yes, if you are not taking as much flax you could try supplementing 100mg of DHA. I realize that is a smaller dose, but my worry is the bleeding time and what you experienced. I suppose if your doctor was not concerned when you mentioned your diet then continuing what you were doing is fine. I suggest asking your doctor is 250mg is too much, or if she or he feels it’s necessary. Keep in mind there is no requirement for DHA it’s the essential fat ALA that we know for certain is required. Here is more on Dr. Greger’s Optimal Nutrition Recommendations, if interested.

          Hope that helps!

  • Danny Con Esperanza

    Perhaps this a stupid question but here goes. knowing that we need a 4:1 ratio, do i simply need for example 40grams of omega 3 and 10grams of omega 6 or is it more complicated than that?

    • Joseph Gonzales R.D.

      No silly at all! It is far more complex because all foods have fats in different ratios, but yes that is the gist. I am not even certain 4:1 ratio is optimal. The idea is getting away from the 20:1 ratio (if not much higher) that most Americans consume. The DHA omega-3 supplements can help balance the ratio but it’s not the whole story. Research suggests the importance of the ratio of omega-6/omega-3 essential fatty acids. ​Dr. Greger discusses, How do you achieve a good omega 3 to omega 6 fatty acid ratio? Very complicated research. Dr. Greger has general information and guidelines about omega-3’s. As a precaution, and especially if following a vegan diet, taking a vegetarian-based DHA/EPA supplement may be a good idea.

  • ldombovic

    I have been watching and reading the information posted on this site for a couple years now. It has changed my life.

    I took a blood panel recently, and all of my numbers were great, except DHA. The range is 0.4%-3.0%. Mine is 3.3%. I eat whole plant foods almost exclusively, and I have never been a fan of fish. I only take 1 algae softgel daily (2 recommended according to bottle). Because I only take 1 softgel, I am getting 160mg of DHA from it.

    I don’t understand how I could have a higher DHA level. I eat seaweed sometimes. Could that affect the increase?
    I understand there is a correlation with low-grade prostate cancer and higher DHA. Please help me understand.

    • Joseph Gonzales R.D.

      Perhaps your body is converting ALA into DHA more efficiently? Turmeric can help that process, as the synthesis of DHA from ALA may be influenced by turmeric’s active compound curcumin. I would really ask your doctor about their thoughts on a higher level. It may be a simple fix, just take a bit less DHA. The study you may be referring to did find more DHA may boost PC risk. Note that DHA is super important but those with high blood levels may be at risk. Ask your doctor about lowering DHA levels. I would suggest not taking it for a bit and see how numbers change, but of course confirm with your doctor. Hope that helps a bit.


      • ldombovic

        Thank you Jospeh. This helps a lot. I have been putting Tumeric on my food, and I eat flax and chia seeds every morning. I may be converting those ALA’s more efficiently. I will reduce my 1 algae capsule a day to once every other day.

  • Brenda Amira

    Dr Greger,
    I have read a lot about the optimal omega 6 to 3 ratio. However, my omega 3s are usually higher than my omega 6s. Is this bad? I can’t find any info about this. Should I increase my 6 so they are at least 1:1? I do not eat huge amounts of Omega 3s. 2T flax everyday and sometimes some chia or a few walnuts. However, I eat no processed foods and no oils. I also keep my fat at @10% so I choose my fat sources wisely. A typical day for me is omega3 between 3.7g -4.4g, and Omega6 around 1.9-2.4. So about a 2:1 ratio the other way. I could easily bring my 6s in line, but don’t want to do so if unnecessary.

    • Joseph Gonzales R.D.

      Good question it’s hard to say exactly. Omega 6 fats are essential and important, but folks typically get enough of these fats. If you are watching your fat intake and keeping it at 10% of total calories you may consider adding a source. Here are the RDAs for essential fats from the Institute of Medicine (IOM). For essential fats, the IOM’s Adequate Intake is 11g/d of linoleic acid (omega-6’s) and 1.1g/d of alpha-linolenic acid (omega-3’s). So yes, omega-6’s are still essential and you need some, but they are not as important to focus on as omega-3’s because they are more widely available from different foods. I will say that numbers and ranges (percentage of total calories and how much should be geared towards fats, let alone essential fats) can be tricky to calculate. We don’t have to me math majors to eat a healthful diet. Research suggests the importance of the ratio of omega-6/omega-3 essential fatty acids.
      ​Dr. Greger discusses, How do you achieve a good omega 3 to omega 6 fatty acid ratio?. See if these links help? Thanks, Brenda.

  • dorange

    Wouldn’t be possible to ” supplement” DHA by eating algae, instead of taking pills? How much algae (and of which kind) is safe to eat is something I am still confused about. Dr. Greger has addressed nori as the one that most favorably alter estrogen metabolism, for example. Is nori high in DHA, too? Would eating the *recommended* one sheet of nori a day, for example, give us enough DHA?

  • EpsilonMarkus

    Dear Dr. Greger,

    I’ve recently stumbled over a website that you may or may not be aware of. I’d addresses the ALA to EPA/DHA conversion rate topic.
    Here is the link to the website:

    It’s supposedly hosted by some colleague of yours, Dr. Udo Erasmus. I haven’t done much research on him or his website yet, but he claims to provide some studies from around 2002 in which above conversion rates have been shown around 36 to 16%, depending on sex. I am not educated in medical science, so maybe you want to have a look into it and bring some light onto whether these studies are reasonable or not?
    I am kind of reluctant to believe in a man promoting scientific research but selling his own products at the same time.
    On the other hand, I have nether really understood what this conversion talk is all about? What are these 5% are supposed to tell key anyway? Maybe the body does not convert more because it does not need more? Could be similar as it is the case with Provitamin A and Vitamin A. You can supplement both, but in the case of Provitamin A only as much will be converted to Vitamin A as the body really needs (or thinks it needs). Maybe Vegans will convert more ALA to DHA, as they have no other souces, whereas in omnivores the body will just not waste energy on the conversion, because it has other sources already?

    Anyway I would be very keen on hearing your opinion on those studies.

    best regards and keep up the good work!

  • Blue lamp

    Could someone recommend an algae based omega 3 supplement that is vegan and does not contain carageenan? Thank you.

    • Angelos Elarja

      Deva, in liquid form.

  • Angelos Elarja

    So in terms of avoiding contaminants and pollutants, algal oil beats fish oil even if it is ”molecularly distilled”. No doubts about that. But what about the issue of stability? Algal oil is still.. oil, and is unsaturated, which makes it sensitive to heat and light. Are there any studies in which commercially available algae-based oils are tested for rancidity and oxidation?
    Im afraid we will have to either stick with dietary ALA and pray for it to convert to sufficient levels of EPA/DHA OR consider adding a few sardines to our diet to ensure optimal EPA/DHA status???

    Dr.Fuhrman says that all omega-3 oils are unstable and algal oil is no exception.
    ”The main problem is that the fat turns rancid as it sits on store shelves.”
    ”Even algae-derived DHA can become rancid if not cared for properly.”

  • Angelos Elarja

    So in terms of avoiding contaminants and pollutants, algal oil beats fish oil even if it is ”molecularly distilled”. No doubts about that. But what about the issue of stability? Algal oil is still.. oil, and is unsaturated, which makes it sensitive to heat and light. Are there any studies in which commercially available algae-based oils are tested for rancidity and oxidation?
    Im afraid we will have to either stick with dietary ALA and pray for it to convert to sufficient levels of EPA/DHA OR consider adding a few sardines to our diet (which seem to be the safest omega-3 rich fish variety on the planet) to ensure optimal EPA/DHA status??? @Michael_Greger_MD:disqus @disqus_wnYOIlS4ks:disqus

    Dr.Fuhrman says that all omega-3 oils are unstable and algal oil is no exception.
    ”The main problem is that the fat turns rancid as it sits on store shelves.”
    ”Even algae-derived DHA can become rancid if not cared for properly.”

  • Marie-Ève Noël

    What are the foods rich in omega 3 and how much should I use them to provide enough DHA to my young child everyday (without using a supplement and without risk to health).

  • Bradley Thomas

    yet flax oil/seed oil has omega 369’s and is highly potent itself? more potent than fish oil? anyway i try to stay away from yeast due to biblical reference, but algae seems pretty neat as well. still no use of not having a diet based around omega three’s. just no reason to. try some cold compressed flax seed oil as a supplement particularly with a vitamin d coating because half the earth’s population is vitamin d deficient or so i’ve heard and you have something rather stimulating and increasing in your productivity. i heard omega three’s were the most important nutrition we get yet i still do not find electrolyte supplements rather simply with all eight combined. the four positives and the four negatively charged i’m guessing ions or particles. and even further still if you make the change from milk to soy milk with added extra dha from silk’s brand you’ll have soy and flax oil that both have omega three’s. these should not be over – looked and should be taken into very careful and accurate gentle consideration. need a safe for the environment way to wipe weeds and mold and mildew and other pests aside from bugs from fields of produce. that would be considerate. maybe there could be some way some scientist could crack some genetic code of bacteria and also mold/mildew and figure out a safe and correct way to wipe off those most common problems from the face of the earth. your algae looked very healthy though. i’m guessing if those were some grains or other type of plant/produce they would look really neat and appetizing.