Doctor's Note

Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos on spirulina. Also, there are 1,686 other subjects covered in the rest of my videos--please feel free to explore them as well!

For some context, please check out my associated blog post: Vitamin B12: how much, how often? and Toxin Contamination of Spirulina Supplements

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  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos on spirulina. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

  • Joel

    Another aspect of toxicity, specifically in Hawaiian spirulina, is a concern expressed by Steve Blake, a N.D. and researcher on Maui . He noted on a visit to Hawaii, where the production facility is located on the Kona coast, that the Kona airport was nearby and that some or many (?) jet landings and takeoffs transited over the spirulina facility. He contacted the company asking if they were aware of jet fuel residue, etc possibly contaminating the algae and has not received a reply.

  • http://www.facebook.com/kdacuna Kristen Acuna

    Hello again! I am planning on conceiving in the next few months and I have been researching prenatal vitamins. Dr. Fuhrman has a prenatal that looks excellent (most importantly, no folic acid) expect it has some spirulina in it. It is listed as an ingredient in the “250mg of a fruit, veggie and greens blend.” Should I continue my search, or is this as good as it gets?

    • Toxins

      It seems, from all the data presented, that spirulina is much more harm than good and that maybe Dr. Fuhrman (a doctor I highly respect) may not have received this information.

    • SArmstrong

      Good for you for planning ahead for the healthiest possible pregnancy! Interestingly, although the idea that pregnant women need to take a special multivitamin is fixed in the minds of the American public, there is no evidence that prenatal vitamins are helpful in Americans, who generally get enough nutrients, even for growing a baby. Multivitamins may help malnourished pregnant women in poor countries, although there is not great evidence for that, either (see the Cochrane data base, www2.cochrane.org/reviews/en/ab004905.html). See also Dr. Greger’s video on multivitamins and breast cancer: nutritionfacts.org/videos/multivitamin-supplements-and-breast-cancer for a discussion of the problems with folic acid supplements. Your safest and healthiest bet is probably to eat green leafy things like crazy starting now, before you conceive. By the way, most doctors and nurses who provide prenatal care will likely advocate vitamin supplements, so you may need to arm yourself with facts from this website! Best of luck with your (future) pregnancy.

    • IndySkye

      You might look up “Propax with NT Factor” – an excellent food-based vitamin/mineral supplement. Available online or via your local “Vitamin Shoppe”

  • Demonva1972

    I know there are vegetarians, especially vegetarian weightlifters that eat spiralina.  Is it the amount that is take and/or where is it from that causes the nuerotoxins?  I had my wife quit taking it after giving her this information.

    • Toxins

      It Appears as though that these toxins are an inherent byproduct of spirulina and unrelated to where the spirulina came from.

      • danielle

        Any piece of scientific evidences ? Please give at least one argument to justify such an allegation …

      • Liz

        According to the research and cmmentary I have read, the toxins are not caused by the spirulina, but are instead caused by contamination. See:

        http://en.wikipedia.org/wiki/Spirulina_(dietary_supplement)
        (I don’t usually cite wiki, but this has the citations for all the claims at the bottom).

        http://umm.edu/health/medical/altmed/supplement/spirulina

        • Thea

          Liz:

          Good research on your part. Dr. Greger covers this very issue in the newest video on the topic of spirulina: (good one to watch)

          http://nutritionfacts.org/video/infant-seizures-linked-to-mothers-spirulina-use/

          I don’t know about you, but if a significant number of products are contaminated, it doesn’t matter to me whether it is the spirulina itself or “just” the contaminants. I’m going to play it safe given that the consequence of getting one bad product is so severe. Just sharing my take on the topic.

          Good luck to you.

  • Veganlinda

    What about Hydrilla Verticillata? Safe?

  • Michael Greger M.D.

    Also be sure to check out my associated blog post Vitamin B12: how much, how often?!

  • Christopherconsciousness

    Spirulina Division Hello, Christopher. The point you raise is the prime reason why it is extremely important to harvest spirulina at a pH over 10 (between 10-11). This is part of the quality control that commercial producers and small-scale producers employ to ensure spirulina’s quality for consumers. If it’s not at the right pH, it simply doesn’t get harvested. The liver toxins you’re speaking of are called microcystins, which are peptides produced microcystis, not by spirulina. Microcystis are unable to survive at such a high alkaline level between 10-11. This is what separates spirulina from another superfood cyanobacteria, Aphanizomenon flos-aquae (aka AFA blue-green algae), which commonly grows up in Klammath Lake in Oregon. AFA, however, cannot grow at the high alkaline levels that spirulina can in order to avoid microcystins. This is the prime reason why I grow spirulina and not AFA, or chlorella for that matter, which also grows at a lower pH. Commonly, people and researchers assume that since AFA and spirulina are both cyanobacteria, their ideal growing conditions are also one and the same, but they usually get lumped together anyway when the research is not complete. It would be helpful if the gentleman who produced the video would learn more about each species and their 

  • Christopherconsciousness

    Hey Mike thought I would share your Spirulina videos with the spirulina division on Facebook. They asked me to tell you to do more research…here is there response, Hello, Christopher. The point you raise is the prime reason why it is extremely important to harvest spirulina at a pH over 10 (between 10-11). This is part of the quality control that commercial producers and small-scale producers employ to ensure spirulina’s quality for consumers. If it’s not at the right pH, it simply doesn’t get harvested. The liver toxins you’re speaking of are called microcystins, which are peptides produced microcystis, not by spirulina. Microcystis are unable to survive at such a high alkaline level between 10-11. This is what separates spirulina from another superfood cyanobacteria, Aphanizomenon flos-aquae (aka AFA blue-green algae), which commonly grows up in Klammath Lake in Oregon. AFA, however, cannot grow at the high alkaline levels that spirulina can in order to avoid microcystins. This is the prime reason why I grow spirulina and not AFA, or chlorella for that matter, which also grows at a lower pH. Commonly, people and researchers assume that since AFA and spirulina are both cyanobacteria, their ideal growing conditions are also one and the same, but they usually get lumped together anyway when the research is not complete. It would be helpful if the gentleman who produced the video would learn more about each species and their differences.

  • Christopherconsciousness

     Spirulina Division The same goes true regarding BMAA — and I’m glad you bring it up to help demystify it. Cyanobacterias are a diverse organism kingdom and BMAA has been associated with certain species of cyanobacteria, but not with arthrospira (this is the spirulina species). This was the point of a response published April 2005 issue of the Proceedings of the National Academy of Sciences (PNAS 102: 5074-5078).

  • JR

    Green vibrance (http://www.vibranthealth.us/). Throw it out?

  • Joe

    What about Chlorella – where are we with that?

  • jonebersole

    Dear Dr. Greger,
    What would you recommend to persons who have consumed spirulina on a regular basis? Are there any “detox” protocols?
    Thanks.

    • Ricardo Baptista

      Please understand this is mostly scaremongering, its completely ridiculous, me and dozens of friends have taken spirulina for years, its completely safe as long as its not tainted (same as something like POTATOES, really). This site is ridiculous in some issues.

  • Christine

    What is spirulina? is a supplement if so what other name would it have? or is it like an additive?

  • lucidvu

    Anatoxin-a in Aphanizomenon blue green algae supplements has been long suspected or known. The abstract cited here doesn’t say that anatoxin-a was found specifically in Spirulina supplements. Are they more specific elsewhere in the paper?

    “These supplements most commonly contain the genera Spirulina (Arthrospira) and Aphanizomenon…A total of 39 samples were analysed in the study. Results showed that three of the samples (7.7%) contained anatoxin-a…”

    Which samples? Spirulina, Aphanizomenon or mixed?

  • By Any

    Information presented in this manner is categorically useless, and intellectually dishonest.

    The questions are:

    1) Is there BMAA in spirulina and/or chlorella?

    2) Is there microcystin in spirulina and/or chlorella?

    If the answer is no, then there is no problem (at least until we discover if there are any other dangerous compounds produced by these organisms).

    The only method of determining the answer is through scientific testing, not rank speculation.

    Keep in mind the study in question was done on algae growing in water ways, and it was beyond the scope of the study to test food or nutritional supplements. That is the obvious next step that must be done.

  • cheryl

    Pure planet premium spirulina is grown in california in a controlled enviroment should that one be avoided as well. I do have an autoimmune illness called Lupus

    • cheryl

      Also, Dr. is the powder just as bad or worst than the capsules.

      • Ricardo Baptista

        SPIRULINA ISNT BAD IN ANY WAY SHAPE OR FORM, DONT TRUST EVERY RANDOM AND BASELESS STUPIDITY YOU READ!

  • Niall Clarke

    Dr Greger,

    I am a keen Endurance Athlete, over fifty and eat only a plant based diet,
    Like all athletes, mine is the battle to recover from hard training or racing,

    most training manuals or experienced athletes write and speak of the benefits of Spirulina, I have always been tempted to try but I’m put of by the information in your 2009/10 video clips, would you have the same concerns for Organic Lab grown Spirlina, should I just exclude it from my diet?

  • Amanda

    Did I miss a discussion od Barley Life or Barley Green (Dried Barley grass juice)? Also sold as multilevel market product, Claims a lot.

  • SiValEngr

    Any update on avocados? I gave up spirulina, and chlorella because of the potential neurotoxins. I also gave up avocado’s because of the gene damage. Any updates on that one? I broke down and had some quac recently . Will I become a mutant?

  • WHISPERING DEER MCKAY

    what is wrong with alfalfa sprouts

  • WHISPERING DEER MCKAY

    what is your take on iron supplements ?