Spirulina and brain health in lab and human studies
What it found
Spirulina shows antioxidant and anti-inflammatory effects in the brain in animal studies, and small human trials suggest it may ease mental fatigue and help malnourished children's development.
The authors say more clinical studies are needed.
What they found
Studies in people
Mental and physical fatigue
In a randomized, double-blind, placebo-controlled study, 3 g per day of spirulina for 1 week produced a small but statistically significant increase in exercise stamina and improved cognitive performance in as little as 4 hours after the first dose.
Malnourished children
In a randomized longitudinal study in infants and children from Zambia, 16 months of spirulina supplementation improved motor development, language, and personal and social skills.
Blood pressure and cholesterol
In people with high blood pressure, spirulina reduced systolic blood pressure and improved endothelial function. Other trials found drops in total cholesterol and LDL cholesterol, and rises in HDL cholesterol.
Antioxidant and immune effects
In healthy elderly people, 8 g per day of spirulina for 16 weeks reduced total plasma cholesterol, increased interleukin IL-2 and IL-6, and raised superoxide dismutase activity.
Animal and lab studies
Brain protection in animals
In many animal studies, spirulina reduced inflammation and oxidative damage in the brain. It protected against memory loss and nerve cell damage in models of Alzheimer's, Parkinson's, and other brain conditions.
Gut bacteria changes
In mice and rats, spirulina changed the mix of gut bacteria, increasing some protective types and reducing others. One study found that a spirulina pigment reduced gut permeability and boosted barrier function in mice.
What the authors conclude
“Despite numerous and encouraging preclinical studies, as well as some initial clinical evidence, additional clinical studies are needed to further clarify the neuroprotective actions of spirulina microalgae.”
Also in their conclusions
- They conclude that spirulina microalgae can support normal brain functions and the development of the nervous system, especially by compensating for nutritional deficiencies.
- They state that preliminary clinical studies suggest a neuroprotective role for spirulina supplementation, particularly in malnourished children.
- They advise that additional clinical studies are needed to further clarify the neuroprotective actions of spirulina microalgae.
How it was done
The authors wanted to understand how spirulina might help prevent or ease brain disorders, and to gather what is known about the molecular mechanisms behind its effects when eaten.
They reviewed experimental studies in animals and cells, plus preliminary clinical studies in people, looking at spirulina's effects on brain health. The human studies included healthy elderly people, people with high blood pressure, and malnourished children in Zambia.
What it can’t tell you
- Many of the brain-protection findings come from animal studies, so they cannot show what happens in people.
- The human studies are mostly small and preliminary, so they cannot prove that spirulina prevents or treats brain disorders.
- This review cannot show whether spirulina is safe or effective for long-term use in people.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- University of Padova, Italy; Maria Paola Belloni Center for Personalized Medicine, Italy; University of Molise, Italy
The paper
- Title
- Spirulina Microalgae and Brain Health: A Scoping Review of Experimental and Clinical Evidence
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Sorrenti V, Castagna DA, Fortinguerra S, Buriani A, Scapagnini G, Willcox DC (2021). Spirulina Microalgae and Brain Health: A Scoping Review of Experimental and Clinical Evidence. Marine drugs. doi:10.3390/md19060293Free full textPubMed 34067317DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error