Spirulina Powder (Arthrospira platensis)
Spirulina is a type of blue-green algae, specifically the dried biomass of the cyanobacterium Arthrospira platensis. It is a microscopic, filamentous organism found worldwide in fresh and marine waters [1]. Often referred to as a "superfood" by the World Health Organization (WHO), spirulina is one of the most popular dietary supplements globally, consumed for its dense nutritional profile and purported health benefits [2, 3]. It has a long history of use, dating back to the Aztec civilization, and gained modern fame after being successfully used by NASA as a food supplement for astronauts on space missions [1].
Nutritional Composition
Spirulina is exceptionally rich in macro- and micronutrients, making it a valuable food source, especially for individuals on vegetarian or vegan diets. Its nutrients are highly bioavailable due to the lack of cellulose cell walls, allowing for rapid absorption by the body [1, 2].
| Nutrient Category | Specific Nutrients |
|---|---|
| Macronutrients | Protein (55-70%), Carbohydrates (15-25%), Dietary Fiber (8-10%), Fats (6-9%) |
| Protein | Complete protein, containing all essential amino acids |
| Vitamins | Vitamin A (as β-carotene), Vitamin B1 (Thiamin), Vitamin B2 (Riboflavin), Vitamin B3 (Niacin) |
| Minerals | Iron, Copper, Calcium, Magnesium, Manganese, Potassium |
| Bioactive Compounds | Phycocyanin, Chlorophylls, Carotenoids, Phenolic Acids, γ-linolenic acid (GLA) |
A single tablespoon (7g) of dried spirulina powder provides approximately 4g of protein, 47% of the Daily Value (DV) for copper, and 11% of the DV for iron [3].
Sources: Karkos et al. (2010) [1], Podgórska-Kryszczuk (2024) [2], Healthline (2023) [3]
Note on Vitamin B12: While often claimed to be a source of vitamin B12, spirulina contains pseudovitamin B12, which has not been shown to be effective or bioavailable in humans [3].
Health Benefits
Clinical research and systematic reviews have explored numerous health applications for spirulina, with evidence suggesting benefits in immune modulation, inflammation, and metabolic health. The primary active component responsible for many of its benefits is phycocyanin, a pigment-protein complex with powerful antioxidant and anti-inflammatory properties [1, 3].
Immune System and Anti-inflammatory Effects
Spirulina is recognized for its ability to modulate the immune system. It has been shown to enhance the production of IgA, an antibody crucial for mucosal immunity, and to increase the activity of Natural Killer (NK) cells [1].
In a randomized, double-blind, placebo-controlled study, spirulina consumption significantly improved symptoms of allergic rhinitis, including nasal discharge, sneezing, and congestion, compared to a placebo. The study demonstrated that spirulina can reduce levels of interleukin-4 (IL-4), a cytokine involved in IgE-mediated allergies, by 32% [1].
Its anti-inflammatory action is largely attributed to its ability to inhibit the release of histamine from mast cells, a key process in allergic and inflammatory responses [1].
Cardiovascular and Metabolic Health
Multiple studies indicate that spirulina can positively impact risk factors for heart disease. It has been shown to:
- Lower Cholesterol: Reduce total cholesterol, LDL ("bad") cholesterol, and triglycerides, while potentially increasing HDL ("good") cholesterol [3].
- Reduce Blood Pressure: Supplementation with 1-8 grams of spirulina per day has been found to significantly reduce both systolic and diastolic blood pressure, likely by increasing the production of nitric oxide, which helps blood vessels relax and dilate [3].
- Manage Blood Sugar: Spirulina may help lower fasting blood sugar levels in individuals with type 2 diabetes [3].
Antioxidant Properties
The antioxidants in spirulina, particularly phycocyanin, are effective at combating oxidative stress. They can protect fatty structures in the body from lipid peroxidation, a key driver of many chronic diseases [3]. This antioxidant capacity also contributes to its potential anticancer properties, with animal studies suggesting it may help reduce tumor size and occurrence [1, 3].
Production and Forms
Spirulina is commercially cultivated in large, outdoor ponds under controlled conditions. The two most popular species for commercial production are Arthrospira platensis and Arthrospira maxima [2]. After harvesting, the biomass is dried and processed into various forms, most commonly:
- Powder: A fine, dark green powder that can be mixed into drinks or food.
- Tablets and Capsules: Convenient for standardized dosing.
Dosage and Usage
Spirulina is generally well-tolerated. A safe and effective dose for adults is typically considered to be between 3 and 10 grams per day [4]. The maximum recommended daily limit is around 30 grams [4]. It is always advisable to follow the dosage instructions on the product label and consult a healthcare professional.
Spirulina powder has a strong, distinct taste and can be incorporated into the diet by adding it to smoothies, juices, yogurt, or salad dressings.
Safety and Precautions
While spirulina is designated as "Generally Recognized as Safe" (GRAS) by the U.S. Food and Drug Administration (FDA), there are important safety considerations [2, 4].
- Contamination: The FDA does not regulate spirulina supplements. Products can be contaminated with heavy metals, harmful bacteria, or toxic substances called microcystins if the algae is grown in polluted waters. It is crucial to purchase spirulina from a reputable and trusted source [4].
- Autoimmune Conditions: Because spirulina can stimulate the immune system, it may worsen symptoms in people with autoimmune diseases such as multiple sclerosis, lupus, or rheumatoid arthritis.
- Drug Interactions: Spirulina may interact with medications that suppress the immune system (immunosuppressants) and blood-thinning drugs.
- Special Populations: Individuals who are pregnant, breastfeeding, or have weakened immune systems should consult a doctor before taking spirulina supplements [4].
- Allergic Reactions: Though rare, allergic reactions can occur and may be severe. Anyone experiencing symptoms like hives, swelling, or difficulty breathing should seek immediate medical attention [4].
