Tuesday, April 9, 2013

Thoughts on Blue-Green Algae, Spirulina, and Chlorella

It’s hard to ignore the hype these three types of algae have created over the past few years. Plant-based athletes are all too willing to boast about how Spirulina is over 60% protein as a counterargument to the “where do you get your protein” question they are constantly bombarded with. These pond scums also claim to have a superior overall nutritional make up, including being a particularly good source of vitamins and minerals. As a result, it’s become a common ingredient for superfood smoothies. Some even recommend drinking the stuff straight by just mixing a bit of the dried powder into a glass of water.

But what is the actual evidence say? Well, yes, all three do have certain properties which could be health promoting; however, blue-green algae and spirulina both come with harmful side effects that, in my mind, outweigh the good. I should note, that I wasn't able to find a ton of research on the topic but what I did find makes me think we are better off staying away from these “superfood” green heroes.

 The problem with blue-green algae and spirulina is they both have the ability to grow neurotoxins. These toxins impact both the brain and the liver and spirulina has also been demonstrated to atrophy muscles rather than building them. What was that about 60% protein?  Now, I don’t know about you, but I'd prefer my superfoods don’t kill me. In April 2005 a coordinated effort of researchers found evidence that almost all blue-green algaes seem to be able to produce a neurotoxin called BMAA (beta-N-methylamino-L-alanine). BMAA is bad stuff. It's been implicated in neurodegenerative diseases and as it turns out there are only two places you will be likely to find BMAA: in the brains of alzheimer's patients and on your pantry shelf.

Some take spirulina simply as a way to supplement B12 into their diet, because it has a considerable amount. But some evidence indicates that this isn't as bio-available as taking a B12 supplement and Dr. Varro Tyler, an authority on herbs at Purdue University, claims spirulina’s is typically contaminated with insect or animal fecal matter. This is not all that surprising since spirulina is grown in open lakes and ponds and is not thoroughly washed before it’s dried.

Chlorella on the other hand, seems to be free from these neurotoxins and other contaminants; however, it doesn’t really offer anything that can’t be found in other dark leafy greens and as Dr. Greger notes, kale tastes better and is much cheaper. So forget the expensive algae and instead focus on eating a clean plant-based diet. You'll get all of the nutrients you need -including protein, you'll save money, and you wont be drinking crushed bugs and fecal matter!


  1. I've always wondered about these guys. Thanks for the insightful post and setting the facts straight!!

  2. Bugs and fecal matter? I shall never eat another spirulina Raw Rev bar again. But really, do you think fruit is washed before it's frozen? It's an epidemic of grossness, I tell you.

    Question, did you happen to read where the BMAA comes from in Alzheimer's patients?

    PS For a minute there I thought you were referring to the athletes as pond scums.

    1. Abby,
      Actually, frozen food is some of the cleanest food you can eat according to some research. I suppose there are always exceptions to the rule, but the food that is frozen is typically better cleaned than most Americans do in their own homes.

      As far as the BMAA I believe it is still a mystery. They have also found larger than normal amounts of metals such as iron, which is why Dr. Bernard recently started advocating against the use of cast iron for cooking.

  3. It`s realy great work on spirulina superfood. I admire your thoughts and your way of expressing and putting it in front of readers is really something that I have seen after a long time. We need more writers like you.
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  4. No BMAA was found in any spirulina sample in the study you mention according to http://www.nutraingredients-usa.com/Industry/Neurotoxin-is-absent-from-Cyanotech-s-spirulina...

    Fecal/insect contamination of spirulina is highly improbable given the culture methods. This is ridiculous. I cultivated spirulina for 3 years in SEAsia under greenhouses with a double-door system. No bug or animal poo could get in there. Not what I've seen in unprotected fields of other cultures...

    1. @ Anonymous, according to this review down by Dr. Michael Greger of Nutritionfacts.org BMAA was found in spirulina.


      He can also see his information and sources here: http://nutritionfacts.org/index.php?s=spirulina

    2. His site clearly states Spirulina itself is not toxic, BUT toxins are introduced when companies add other toxic producing ingredients to their batch. So he advices avoiding it in general because as he claims no company will spend the money to test their batches.

    3. Hi, I'm the lead researcher on a recent publication which describes BMAA potentially triggering motor neurone disease. See http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075376

      It's now known that more than 95% of cyanobacteria or blue green algaes make BMAA. Recently it was also show that so do dinoflagellates. BMAA bioacummulates up the food chain - which is how it was first identified, when it was linked to a neurological disorder on Guam. We now know how this likely happens - by replacing serine in the protein chain, so it gets stuck in your proteins.

      I know just about everyone who works in the field of BMAA and MND which means I also know people who are able to test for it and I can count those labs on one hand. I also know labs who have never been able to find it. BMAA is notoriously hard to detect so unless the product (eg spirulina) is tested in a lab that I know has the expertise to find it, then I don't believe that a negative test result means absence of BMAA.

      Regarding BMAA - it is made by the algae - probably as a signalling molecule to indicate low nitrogen stores. It's not introduced in the processing stages. My concerns regarding it being sold as a supplement are many, but one is that unless every batch is tested every time for BMAA (and I know they're not because as I said I know all the labs capable of testing BMAA) then there is no way to know if the batch is contaminated. Frankly, one test from 2005 doesn't cut it for me.

      We have evidence now that long, low levels of exposure to BMAA can trigger MND in susceptible individuals. We know it accumulates in seafood, such as shark, lobsters, crabs, prawns and mussels. And yes, it's been found in the brains of Alzheimer's Patients from North America.

      I'm with the author - it's just not worth the risk. Have a steak, have some kale. Get your protein elsewhere. Just because it's natural doesn't make it safe.

      I will emphasise however that I am not saying all spirulina has BMAA - I don't know, I haven't tested it. And I'd garner neither do the manufacturers' as they've not tested it either.

      Also thanks for the article. I've been getting a lot of correspondence from people since our paper was published and when they've asked the manufacturer of their brand of spirulina if it's safe, they've been told yes. I know this is BS and nothing makes me more mad than companies that lie to make a profit. I was also contacted by someone recently about a similar article to this that I wrote and put on my own site, who then went off and wrote a totally credulous puff piece on how it's a superfood.

      If you're an adult - go ahead and put whatever the hell you like in your body, but you have a right to be informed of the risks before you do. We need more articles like this to pop up when people search spirulina on the Googles machine.


  5. Thanks for sharing, Anthony! I'm a big fan of chlorella and organic spirulina though I didn't know these have many health benefits. The latter I always add to my smoothie. :) Have you tried that?