Incidentally, the link in that first tweet goes to their website where you'll find the following statement "Only certain strains of Spirulina will produce BMAA, so check you know you're buying a pure strain (and never from a natural lake). Additionally, when Spirulina undergoes a proper drying process, it is incapable of producing any BMAA."
BMAA is an amino acid that is not destroyed by boiling or heating. It is produced whilst the algae is growing, but can be removed by sand or charcoal filtration. "Drying" will not remove it, in fact it will likely just concentrate it.
As for "only certain strains of spirulina will produce BMAA", well the term spirulina seems to refer to dietary supplements made from Arthrospira platensis and Arthrospira maxima,
two types of cyanobacteria or blue green algae, or more commonly, pond scum.
Why on earth people would want to drink pond scum? Well because cyanobacteria/Spirulina has been cleverly marketed as a superfood
to the wellness community. Indeed, it has had waves of popularity over decades, but can now be commonly found in juices in the supermarket, or as protein boosts in smoothies or as tablets and powders sold in chemists and supermarkets.
In response to a similar enquiry about the safety and presence or absence of neurotoxins in BMAA, another company told a customer this:"You will find that BMAA is only produced by certain kinds of Spirulina grown in natural lakes and unregulated water sources. ....In addition to this, our Spirulina is spray-dried during production, in which no cell capable of producing BMAA can survive..."
As I've already mentioned, BMAA is a tiny amino acid, so spray drying the algae will not likely remove all the BMAA.
"Our Spirulina is of the Arthropsira Platensis variety, and is not related to the BMAA-producing strain. (Our) spirulina is actually grown in carefully monitored cultivation ponds, where conditions are constantly observed. ..."
It doesn't really matter if you are "constantly observing" your ponds or not, it's not like the cyanos will only make BMAA *if you're not looking*.
Still, for a species that is over 3.5 billion years old, we know surprisingly little about cyanobacteria, including why it makes BMAA.
(Curiously, even though BMAA is a "nitrogen heavy" molecule (it has 2 nitrogen atoms) cyanobacteria synthesise it in times of nitrogen deficiency. For this reason, we think it might be used to store nitrogen, which would also explain its symbiotic relationship with plants, especially cycad palms
What we do know however, is that cyanobacteria produce BMAA under very specific conditions, often when they are starved of nitrogen, which can happen if they grow in a "natural lake" or not.
To be fair though, the evidence for Arthrospira
producing BMAA is nowhere near conclusive.
from 2014 did not find BMAA in Arthropsira Platensis
, but the authors cautioned;"Although these results are reassuring, BMAA analyses should be conducted on a wider sample selection and, perhaps, as part of ongoing Spirulina production quality control testing and specifications."
Another more recent paper
tested 39 samples of commercially available Spirulina from health food shops in Canada and found that 14 of them were positive for BMAA with levels ranging from less than 1 to more than 100 μg/g.
"Using this method, we have identified and quantified BMAA as well as AEG and DAB in several natural health products containing Spirulina, a form of cyanobacteria, or blue-green algae, also known as Arthrospira."
Part of the reason for these discrepancies can be attributed to the many pitfalls associated with detecting BMAA. For one thing, it's present in very low quantities so requires very sensitive, high-end techniques to detect it. It also has an isomer (which is a compound that is very similar in structure) that can often be mistaken for it. And finally, it's often present in complicated matrices such as algae or seafood, so separating it out is fraught with complications.
So in summary, cyanobacteria don't always make BMAA but we don't know how to stop them making it either. Growing them in special ponds whilst giving them death stares or drying them in a special way does not guarantee your powder or pills will be free of BMAA.
The only way to be absolutely sure that your Spirulina is clean is to test every batch, every time
. There are now well established methods
to do this, but I doubt we will see producers adopting them anytime soon. This is partly because Australian government regulations do not require supplements to be tested for contaminants, but also people are under the impression that if it is natural, then it must be safe.
But this is not always the case, as demonstrated by studies
that show supplements can be contaminated with “banned” and often dangerous substances. Just because it's natural doesn't mean its safe.
n the end though, you need to consider whether the benefits outweigh the risks. The benefits here are you get a big dose of protein, and the risks are you're increasing your risk of getting a neurodegenerative disease.
Here's my advice, have a steak or a big chunk of tofu. They taste better anyway are much less likely to give you Alzheimer's or motor neurone disease.