Spirulina is a type of non-toxic blue-green algae (cyanobacteria). It may refer to a number of different species in the Arthrospira genus, namely platensis and maxima. Spirulina is often used as a vegan source of protein and iron and is rich in a variety of other nutrients and phytochemicals. It is believed by some to provide vitamin B12, but it actually contains the dubious pseuodovitamin B12 which hasn't been shown to be effective. Spirulina has a few notable active components. The main ingredient is called phycocyanobilin, which makes up about 1% of spirulina. This compound mimics the body’s bilirubin compound, in order to inhibit an enzyme complex called nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. By inhibiting NADPH oxidase, spirulina provides potent antioxidative and anti-inflammatory effects.
What are spirulina's benefits?
Evidence suggests a general improvement in the basic components of the lipid panel: triglycerides, HDL, LDL, VLDL, and total cholesterol. It seems to reduce blood pressure by a small amount, and may have some meaningful effects on liver enzymes and overall liver health, though more research is needed on that. It also seems to improve general antioxidant status and reduce markers of oxidative stress, as well as some inflammatory markers. When people take spirulina, they tend to lose a small amount of weight, even if they're not trying to, and there's some evidence to suggest that it can help regulate appetite.
Because of its potentially potent immunomodulating properties, spirulina may have utility for preventing allergic reactions and treating asthma. However, there's only a small amount of research for these indications. Another possible benefit is improved athletic performance, with both resistance and endurance exercise, but the evidence is still preliminary.
While most spirulina products are safe, there have been reports of contamination with toxic microcystins from other bacteria. It is advisable to ensure that any spirulina products have been throughly tested for safety before consumption. In general, spirulina is safe and adverse events aren't common in clinical trials.