Algae have long been used as food due to their varied nutritional profiles. The potential of microalgae such as chlorella and spirulina, as well as algal oil, to support energy, detoxification and general health makes them a promising option for food supplements.
What Are Algae?
Algae are a diverse group of organisms found in both fresh water and salt water. They range from microscopic microalgae to larger macroalgae such as brown, red and green algae.
Chlorella and spirulina are commonly used in food supplements. Chlorella is a single-celled green alga, while spirulina is biologically classified as a cyanobacterium. Both contain proteins, minerals and natural pigments such as chlorophyll and carotenoids.
Algal oil is obtained from selected microalgae and contains the long-chain omega-3 fatty acids docosahexaenoic acid (DHA) and, depending on the species used, eicosapentaenoic acid (EPA). It therefore provides a plant-based alternative to fish oil.
What Makes Algae Interesting?
Chlorella and spirulina are characterised by their varied composition. Their characteristic components include proteins, unsaturated fatty acids, minerals and antioxidant pigments.
One study investigated the potential effects of chlorella and spirulina on various cardiovascular risk factors. The results indicated possible beneficial effects of spirulina on blood pressure in particular.
Algal oil is especially interesting as a plant-based source of DHA and EPA. DHA contributes to the maintenance of normal brain function and vision. EPA and DHA also contribute to the normal function of the heart.
Further areas of research include antioxidant cell protection, the immune system, lipid metabolism and inflammation-related processes. The ability to bind certain unwanted substances and potentially support the body’s natural elimination processes is also being investigated.
A Versatile Ingredient
Depending on the desired formulation, algae can be used as powders, compressed forms, extracts or oils, for example in capsules, tablets, powder blends and liquid products. They are suitable for both single-ingredient products and combinations with vitamins, minerals or other plant-based ingredients.
The species of algae used, cultivation conditions, manufacturing process and standardised nutrient content all play an important role in product development. Testing for heavy metals and other unwanted substances is also particularly important.
Certain marine algae may contain very high levels of iodine. The iodine content should therefore be clearly stated and taken into account when determining the dosage. People with thyroid conditions or allergies, those who regularly take medication, and pregnant or breastfeeding women should only use algae supplements after consulting a healthcare professional.
Sources
Bavarian Consumer Information Portal (2023): Algen in der Ernährung.
European Commission: Commission Regulation (EU) No 432/2012 Establishing a List of Permitted Health Claims Made on Foods.
Pinto-Leite et al. (2025): The Role of Chlorella and Spirulina as Adjuvants of Cardiovascular Risk Factor Control: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Nutrients, 17(6), 943.
Craddock et al. (2017): Algal Supplements of Vegetarian Eating Patterns Improves Plasma and Serum Docosahexaenoic Acid Concentrations of Omega-3 Indices: A Systematic Literature Review. Journal of Human and Dietetics, 30(6), 693-699.