I was inspired to write this week's Microbial Mondays post after buying some Spirulina in a health food store. To be honest, I bought it partially because it's a very good source of protein, but mostly because I love the colour it gives food (brilliant blue-green!) and the fact that it's a microbe.
You may have heard of spirulina being touted as a "superfood". In general, I'm usually pretty suspicious of so-called "superfoods", because I distrust any nutritional hypes (nerd alert) that I haven't yet confirmed to be well supported in scientific literature. For instance, when I give kombucha workshops, people usually come in expecting me to fangirl over its health benefits. But nope - as detailed on a previous Microbial Monday, for the most part the health benefits of kombucha haven't been scientifically confirmed. I just like the taste.
So, when I bought my spirulina, I decided to take a dive into the literature on this one, too, and share it with you, my fellow microbe enthusiasts and healthy skeptics. Here we go! To start us off… what the heck is spirulina anyways?
I bought mine as a powder in a glass jar, and when I opened it, I found that the smell gave me a good clue as to where it came from. It smells like old seaweed. Seaweed, by the way, is an algae, a type of microorganism that is indeed small but very different from bacteria. However, although the group of microbes that spirulina belongs to has also been called "blue-green algae" somewhat incorrectly, spirulina isn't an algae, despite it's smell. Spirulina is a type of cyanobacteria!
Smelly smelly spirulina
We've talked a little about cyanobacteria before on Microbial Mondays. They are a pretty good subgroup of bacteria that are able to photosynthesize, i.e. make their own food from just water and sunlight, just like plants. Cyanobacteria have been around for billions of years - some of the oldest known fossils are of these little guys - and are thought to be responsible for kick-starting the production of oxygen on Earth. That's right, the very first oxygen. The atmosphere used to have a totally different composition of gasses in it! But that's another story for another week. Let's get back to Spirulina.
Spirulina have been used by humans for food for a long time - as far back as the Aztec civilization. More recently, it's been used as a dietary supplement for decades, with no reported side-effects or toxicity when used in moderation. It is indeed a great source of protein - by weight, it is up to 70% protein, which is more than three times the protein content of red meat. It also contains vitamins like beta-carotenes and vitamin B12, as well as minerals like iron.
But all that wasn't enough to call it a superfood. People have also claimed that spirulina is a miracle food that can be used to treat chronic fatigue and allergies, and that it has health-boosting antioxidant powers. Let's take a look at the evidence for each of these, shall we?
Let’s start off with the supposed ability of spirulina to cure chronic fatigue. This one seems to be the worst-supported claim. For instance, in trials with humans who took either spirulina or a placebo (an inert pill – like a sugar pill, for instance), the people taking spirulina didn’t seem to have any increased energy compared to the people taking the placebo. However, spirulina does contain healthy, energy-providing fats and sugars. So, while it might not be a miracle cure for chronic fatigue, it is still a good, nutritious food. The take-home lesson from this part? It’s not a miracle food in this regard, but it ain’t bad.
The second big claim about spirulina’s powers is that it helps combat allergies. I found this claim particularly interesting, because there are actually quite a few studies showing that eating spirulina can have anti-inflammatory effects in not only animals, but also human cells in petri dishes and entire humans. Simply put, allergy is simply a problem of too much inflammation in response to things that should be harmless, like peanut butter or pollen. So, I thought that this claim could make some sense.
However, it’s still not totally clear to scientists how the anti-inflammatory action of spirulina could work. Some studies have found that spirulina can stop cells that come into contact with allergens from sending out messages that say, “Inflammation needed! Come help me, immune cells!”. Other studies have found that it changes the amounts of antibodies in and around and on your body, which could change the flavour of your immune response to allergies, from a more “ATTACK AT ALL COSTS!!!” type of response, to a more calm, “Let’s see what this is all about before first, and then act accordingly” type of response. Still other studies suggest that maybe the more immunological actions of spirulina could simply be due to spirulina being a great food – and if you eat a healthier diet, your immune system will also be healthier and more effective overall. As of now, I’m partially convinced on this one after digging through some scientific papers. I’m going to keep eating spirulina in moderation, because although we still don’t know exactly how it can modulate your immune system, it seems like most of the time any “immunomodulatory” (immune-system-changing) effects that spirulina has are usually beneficial.
Finally, last but not least, we get to the antioxidant properties of spirulina. This one I want to dig into a little deeper, because I hear people throwing around the word “antioxidant” all the time, without really knowing what it means. To understand what an antioxidant really is, first you need to know what the opposite means. So, what is an oxidant?
Remember learning about the parts that make up atoms in high school? If not, here’s a quick refresher. Each atom in the entire world is made up of the same three basic ingredients: protons, neutrons, and electrons. And, everything in the world, including your cells, is made up of atoms.
We usually think of atoms as being pretty stable, except when we use them in bombs, but in fact they lose little bits of themselves all the time. Or rather, little bits can be stolen, by thieves like oxidants! Oxidants are simply electron thieves: they steal these little subcomponents of other atoms for themselves. Sometimes, oxidation is a very good thing for us. For example, oxygen, which we humans are totally reliant on, is one of these electron thieves! In this case, our bodies have evolved to use oxygen’s electron-stealing prowess to our advantage. But, like with everything in biology, there can be too much of a good thing. Biology is all about balance. If too many electrons are stolen away, our cells get very stressed out. If the cells can’t get any electrons back, they will totally freak out, and commit cellular suicide. That’s right: if our cells lose too many electrons, they will kill themselves. You can imagine that having suicidal cells isn’t a great condition for a multicellular animal for us to be in.
That’s where antioxidants can come in. antioxidants simply do the opposite of oxidants: they give electrons! This solves the problem of the suicidal cells. They get some electrons back, and the cellular life can go back to normal. Although there have only been petri-dish-style studies on the ability of spirulina to act as an antioxidant, and no studies with entire humans or other animals, the petri dishes tell us that spirulina is a pretty good antioxidant. But to me, the biggest question with antioxidant foods is not if they are really antioxidants, but if we really need them as much as the food industry tells us.
Indeed, antioxidants can be great, if you have been exposed to too many oxidants. Things like exercising too much, injuries, smoking, environmental pollution, radiation, and eating highly processed foods can send too many electron thieves your way. If you are exposed to any of those things, then indeed eating some extra antioxidant foods can’t hurt. However, if you’re living a normal, reasonably healthy life, you don’t need to be stuffing spirulina and blueberries down your throat. Again, it seems to me that balance is the most important thing. Got oxidants? Get antioxidants. Got inflammation? Go for anti-inflammatories. If you’re not inflamed or oxidizing, you’ll probably be just fine without loads of spirulina.
So, the take home message for this week? There are no “superfoods”, just many different natural, healthy ingredients that are super in moderation.
Until next week - let us eat (spirulina) cake. Just a few slices.
~Alex
My spirulina cake!