Phycocyanin, spirulina's blue secret: benefits & dangers

What are the benefits of phycocyanin, the key compound in spirulina?

Definition of phycocyanin

Phycocyanin is a natural pigment that gives spirulina its intense, vibrant blue colour, which is very rare in the living world.

Along with chlorophyll, it allows spirulina to capture sunlight and transform it into electro-biochemical energy. But behind this mysterious blue colour lies one of the molecules of the 21st century.

Today, phycocyanin, which accounts for more than 20% of spirulina's weight, is raising huge hopes in medical research.

Firstly, because its unique structure gives it multiple potential effects on human health. Secondly, because it has natural fluorescent properties, potentially very useful in medical imaging. Finally, because it has the capacity to replace synthetic food colourings, whose potential long-term side-effects are regularly the subject of debate.

Studied benefits of phycocyanin

The potential health benefits of phycocyanin currently being studied by the scientific community are:

• its contribution to the natural antioxidant system. Multiple mechanisms of action are thought to be involved, including a reduction in the production of reactive oxygen derivatives (RODs), which are known to play a harmful role in excess (1);
• its influence on the integrity of the immune system.  The potential dynamisation of the thymus, which plays an important role in cellular immunity by promoting the activity of white blood cells, is currently under study (2);
• its anti-inflammatory properties. In particular, phycocyanin is thought to help inhibit the expression of certain enzymes involved in the inflammatory process, such as cyclooxygenase-2 (COX-2) and nitric oxide synthetase (3);
• its effects on cell apoptosis (programmed cell death). This is a very promising avenue, which has led to the experimental use of phycocyanin as a complementary agent to chemotherapy (4-5).

Most of these effects are still being studied, but as results are published, one idea is gaining ground: most of the benefits claimed for spirulina could be linked to phycocyanin.

And the market has taken notice: studies estimate that the demand for phycocyanin will reach 233 million dollars in 2028, compared with just 122 million in 2018 (6).

Where can you find phycocyanine?

Like other phycobiliproteins, the family to which it belongs, phycocyanin is a rare molecule.

Only three types of living being contain it:

• cyanobacteria (formerly known as ‘blue-green algae’), such as Spirulina and Aphanizomenon flos-aquae (AFA);
• glaucophytes, a small, discrete group of single-celled algae found in freshwater environments;
• red algae, which contain much less. Fermentation cultures of the red micro-algae Galdieria Sulphuraria are being developed to produce phycocyanin in a different way.

For the time being, spirulina remains the best option for taking full advantage of phycocyanin's potential.

What are the other benefits of spirulina, the leading source of phycocyanin?

Basic facts about spirulina

Often presented as a micro-algae, spirulina is in fact a microscopic bacterium (cyanobacterium) of the genus Arthrospira.

The misunderstanding arises because it grows in brackish water, where it forms slimy filaments.

These bacteria grow best in warm, salty lakes (which also contribute to their blue-green colour), such as Lake Chad in central Africa and Lake Sambhar in India.

The Aztecs harvested large quantities in the ancient lakes of Mexico and consumed them in the form of dried cakes.

The health benefits of spirulina

The benefits of spirulina go far beyond those of phycocyanin.

Spirulina is generally recognised as an antioxidant, immunostimulant and anti-inflammatory substance, as well as being invigorating, slimming (because it promotes satiety), detoxifying and highly nutritious.

This cyanobacterium contains large quantities of high-quality protein (2.5 g to 3.5 g of protein per 5 g), a variety of antioxidants (lutein, zeaxanthin, cryptoxanthin, etc.), beta-carotene, a precursor of vitamin A (12,000 to 25,000 IU per 5 g), iron (3 to 8 mg per 5 g) and gamma-linolenic acid, an essential fatty acid (around 50 mg per 5 g).

Spirulina is particularly recommended for:

• athletes
• vegetarians and vegans (particularly for its high protein content, but not for its vitamin B12 content, as the form of B12 contained in spirulina is not biologically active in humans)
• growing children and teenagers
• people who are stressed and overworked
• convalescents and people suffering from chronic fatigue
• senior citizens

How do I choose my spirulina supplement?

You can, of course, take spirulina in powder form and in bulk (generally at low cost), as it is a food.

However, it is easier to store, transport and maintain stable doses over time in the form of a food supplement in capsules.

If you opt for spirulina capsules, which are a source of phycocyanin, make sure that the cultivation, drying and production conditions are good, by consulting the certificate of analysis.

Spirulina must be tested for microcystin, β-N-Methylamino-L-alanine and heavy metals.

Only certain supplements meet these various conditions, guaranteeing both effectiveness and safety (this is the case with the Spirulina food supplement, whose ingredients are supplied by the world's leading spirulina producer, Parry Organic Spirulina).

Can phycocyanin and spirulina be dangerous?

Spirulina and phycocyanin are widely consumed and studied

There are several species of spirulina, but A. platensis, A. maxima and A. fusiformis are considered to be the safest for human consumption.

The many toxicological studies carried out on spirulina have not revealed any acute or chronic toxicity, nor any teratogenic or genotoxic effects.

In fact, spirulina is now one of the most widely sold food supplements in shops and on the Internet.

Health safety agencies regularly receive reports about spirulina, but the side effects observed always depend exclusively on the growing conditions: certain extracts sometimes contain too many heavy metals, such as lead or cadmium, because the growing environment is polluted.

To avoid this, always select recognised manufacturers and sellers, and supplements that clearly mention the presence of spirulina rather than 'blue-green algae'.

Furthermore, no study has been able to show any toxicity from the more specific administration of phycocyanin.

Contraindications for spirulina

There are a few contraindications to bear in mind.

People suffering from phenylketonuria (a rare genetic disease caused by an enzyme deficiency that prevents the breakdown of phenylalanine, an amino acid found in spirulina) or people allergic to spirulina must avoid taking spirulina.

Spirulina is also not recommended in cases of autoimmune diseases or gout. It should not be taken during pregnancy without medical advice.