What is spirulina?

Spirulina is a freshwater algae (or seaweed) that grows naturally in tropical and sub-tropical lakes. Historically used as a food by native South American people, it fell into disuse for many centuries until it was recognised as a non-animal protein source in the 1970s. It's dried and made into cakes for use in soups and stews around the shores of Lake Chad, West Africa.

Because it's a supplement rather than a mainstream food, spirulina has not been as widely or deeply researched as other major foods. It offers the full spectrum of amino acids (proteins) but is not considered to be as complete in other nutrition as milk, eggs or meat. It could be of great use where protein is rare, but not as useful in the Western world, where availability of plant-based protein is not an issue.

Vegetarians regarding spirulina as a major protein source will miss out on nutrients unless they're also including eggs and milk in their diet, or still relying on the correct balance of grain and pulses they eat. It could be more useful to vegans, but speak to a GP about your overall diet first – you might need to supplement, for example, vitamin B12.

Learn about the health benefits of spirulina.

How to use spirulina

Spirulina can be used in stocks and soups, but is usually added to juices and smoothies. Some find the taste and colour off-putting, but you can get around this by taking capsules.

How to store spirulina

Follow pack instructions carefully.

Availability of spirulina

Sold in powder, tablet, capsule and flake form.

Choose the best spirulina

There does not appear to be much difference nutritionally between any of the forms available, so make a choice according to how you want to use it or on price. There are variations in taste, so you may want to sample these to discover which you prefer. Taste and cost are probably the major hurdles to leap before including spirulina in your diet, and probably explains why spirulina is not on everybody’s shopping list.