Spirulina side effects: the dangers of microcystin toxins in blue-green algae
Spirulina is a type of blue-green algae that has been touted for many years as a healthy food supplement. In the last twenty years there has been much discussion about certain side effects of spirulina and their causes. Some Spirulina producers have also avoided the problem a lot, and likewise there has been so much hype of the problem from the other side. Much of this has grown out of a confusion over what is really meant by spirulina, what different types are available, and how they are prepared. The truth is that certain products sold as spirulina are often made from other blue-green algae which, when improperly prepared, can contain very dangerous levels of toxins that attack the liver. There is also very little regulation in its production. So how does the consumer know which types are safe and which ones or not? Or should people just avoid it altogether?
The issue surrounding the possible severity of spirulina side effects first emerged in 1999 with a warning from the Canadian Health Protection Branch that spirulina products could contain potentially dangerous levels of toxins known as microcystins. These toxins can cause serious liver damage in large doses. They found that products made from certain wild-harvested blue-green algae contained levels of microcystins that were above the maximum daily intake recommended by the World Health Organization. These products are often sold as spirulina. The report stated that: “Adverse symptoms from prolonged use of these products (weeks to months) may not be obvious, but can range from a general feeling of malaise or gastrointestinal discomfort to jaundice.” However, they stated that “based on the results, products made only with spirulina blue-green algae are no longer considered a microcystin-related health risk.” In other words, the reported side effects of spirulina are, in fact, not caused by spirulina at all, but by other species of blue-green algae. So how do we know exactly what is safe and what is not?
The problem is that there is a lot of confusion about what can actually be called spirulina, and several other blue-green algae are falsely sold as spirulina. The main species of blue-green algae that is part of good quality nutritional spirulina is known as Spirulina platensis. In fact, scientists have decided that the species belongs to a different genus, which is why it is now officially known as Arthrospira platensis. However, in common usage it is still referred to as spirulina, and this is what consumers should look for in spirulina supplements if they want to avoid all of the supposed side effects of spirulina.
In May 2000, the Oregon Department of Health further helped identify the culprit. They stated in their report that many blue-green algae products on the market contained a species called Aphanizomenon flos-aquae. This is not a Spirulina species and is generally harvested from the wild, often from Upper Klamath Lake in southern Oregon. The problem with this is that another species of blue-green algae is common in that lake known as Microcystis aeruginosa. This is one of the species that produces microcystin toxins and is often inadvertently harvested together with Aphanizomenon flos-aquae. These microcystins then end up in products sold as spirulina and are to blame for the reported side effects.
From these two reports, it is clear that taking the wrong blue-green algae products can have potentially serious consequences. But the truth is, the reported spirulina side effects are actually caused by other species of blue-green algae that are sold as spirulina. True Spirulina is a nutrient-packed product and has been acclaimed by the World Health Organization for having great potential to combat global malnutrition. NASA has also suggested that it could be an excellent food to grow on long-distance space travel. There are companies that are highly regulated and sell very good quality pure Spirulina platensis grown under controlled conditions. There is also a strain known as Spirulina pacifica or Hawaiian Spirulina that has been developed by Spirulina platensis scientists and is also highly regulated in its production. These are the companies people should turn to if they want to reap the benefits of blue-green algae without the potentially dangerous side effects.