I first discovered spirulina as a student dietitian when my student budget and predominantly vegetarian (but obviously not balanced enough) diet left me anaemic and iron deficient. In search of additional ways to add iron to my diet I came across spirulina in my local health food shop and started using it irregularly as a supplement. Having not used it for years, when I was recently sent a sample of spirulina powder I thought it was a good opportunity to give it another try.
What is spirulina?
Spirulina is an edible blue-green algae that grows in alkaline lakes in sub-tropical areas. Historically gathered and dried directly from the lake by the ancient Aztecs. the spirulina available today is harvested and usually available in either powder or tablet form. The supplement is often labelled a Superfood with a wealth of health claims to it’s name – everything from treating asthma or depression, boosting energy levels, detoxifying the liver, improving memory… Unfortunately the scientific evidence doesn’t support any of these claims though. One thing spirulina can claim though, is that it is nutritious. Rich in protein and a number of micronutrients, it’s often consumed by people on vegetarian or vegan diets to improve their nutrient intake. It can be mixed into drinks or foods and eaten in a number of different ways.
Made up of around 60% protein, 100g of dried spirulina powder typically provides 120mg Calcium, 29mg Iron, 195mg Magnesium, 570IU Vitamin A, 5mg Vitamin E and 25mg Vitamin K according to the USDA Nutrient database. Interestingly, it states that spirulina contains 0mg of Vitamin B12 which I’ll come onto in a minute.
I did find the labelling on this particular brand of spirulina a bit confusing, as some of the vitamins and minerals (Iron, Magnesium, Vitamin A and Vitamin E) were listed per kg rather than per 100g as per standard labelling. It would have been good to have nutritional information for a serving size as well as most people aren’t going to eat 100g at a time!
I got my measuring spoons and scales out and discovered that 1 level 5ml teaspoon of spirulina powder weighs 3 g. While the nutrition claims per 100g are quite impressive, each 3g teaspoon actually only provides about 2g of protein, 4mg of calcium and less than 1mg of iron. If this was my only source of iron I’d almost need to eat 15 teaspoons a day to reach my requirements!
Whats worth taking note of is how bioavailable some of these nutrients are (or aren’t). Often claimed to be a good source of vitamin B12, current research suggests that spirulina is an inconsistent source of vitamin B12 and shouldn’t be the sole source for vegetarians or vegans. Unfortunately the form of B12 found in spirulina is inactive and isn’t utilised by the body. I’m assuming that this is why the USDA database reports the Vitamin B12 content as zero. Some reports have suggested that any Vitamin B12 content could actually be due to contamination of other substances.
Personally I find spirulina to have quite a strong, metallic taste which makes sense when you think if how rich in iron it is. Some people say it is tasteless while others say it tastes like pond scum. It’s quite strong because when I added just one teaspoon to a glass of juice it took me about 5 minutes to drink rather than the usual one or less!!
Thinking that perhaps the flavour could be better disguised with food I then took to the kitchen to see whether food could mask the flavour. I made a recipe for choc mint spirulina balls using dried fruit, nuts and cocoa powder which were quite nice, but even then I found the flavour remained. With a bit of a metallic taste to it, spirulina is likely to be one of those ingredients that takes time to get used to, or just needs to right recipe to disguise it’s flavour. With plenty of recipes using spirulina out there like the ones I’ve collated below I’m sure I’ll find some I like!
While spirulina supplements have been deemed safe for human consumption, there have been cases of toxin contamination and for this reason they shouldn’t be used by pregnant women. People taking warfarin or anticoagulants should avoid spirulina due to drug-nutrient interactions and it should also not be used by people with phenylketonuria (PKU) as it is high in both protein and phenylalanine.
Spirulina is a nutritious supplement, but with a typical dose being 1-2 tsp it’s not going to meet all of your nutrition needs in one go. A teaspoon or two a day would help add iron to your diet if you follow a vegetarian or vegan diet and have an inadequate intake. Like most supplements, it’s a bit on the pricey side. You might want to try it first to avoid having an unused packet just sitting there in the cupboard should you find you don’t like the taste. If it’s not within your budget, you aren’t going to be missing out if you have a healthy balanced diet. Just like the name supplement says, it can be used alongside or to boost a balanced diet – not fix it!
- Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets 748 / June 2003 Volume 103 Number 6 (PDF)
- Nutrition Spirulina, dried USDA Nutrient Database
- Karkos (2011) Spirulina in Clinical Practice: Evidence-based Human Applications. Evidence-based Complementary and Alternative Medicine Volume 2011, Article ID 531053, 4 pages. (PDF)
- Marles (2011) United States pharmacopeia safety evaluation of spirulina. Crit Rev Food Sci Nutr Aug;51(7)593-604 (Abstract)
- Spirulina Vanilla Bars – Oh Almond
- Spirulina Pie – One Green Planet
- Gluten free protein bar – Healthy Eats
- Raw spirulina energy crunch bars – Healthful Pursuit
- Spirulina cookies – Veganlogy
- Spirulina guacamole – Young and Raw
- Spirulina protein power balls – The Healthy Chef
- Chocolate spirulina energy bar – Apples and Ginger
- Healthy Choc Mint Slice – Super Foods for Kidz
- Raw Chocolate Fudge Cookies – Eat 2 Evolve
- Pasta Fresca Allaga Spirulina – Caffe in Forchetta
This product was provided as a free sample and has not influenced my opinion as per my disclosure policy.