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!