Review · Biomolecules · 2021Conflicts declared

Blueberry supplements, brain health and how anthocyanins are delivered

What it found

Blueberries and their anthocyanins have shown protective effects on brain cells and thinking in lab tests, animals and some human trials.

However, anthocyanins are poorly absorbed, so the form and timing of intake matter.

What they found

Studies in people

Human memory trials

In some human trials, older adults who took blueberry powder or extract for 12 to 24 weeks improved on memory and word recall tests. One trial found no improvement in gait or balance, but fewer repetition errors on a learning test.

Children and acute effects

In children aged 7 to 10, a single blueberry drink improved short-term memory and mood for up to 6 hours. The best performance was seen with a 30 g dose.

Animal and lab studies

Brain cell protection

In lab tests, blueberry extracts reduced inflammatory signals and protected brain immune cells from damage caused by glutamate or alpha-synuclein. These studies used microglia and other brain cells.

Animal memory and aging

Aged rats fed blueberries showed improved spatial memory and increased markers of brain plasticity. Other rat studies found less microglia activation and lower inflammatory cytokines.

Poor absorption

Anthocyanins are unstable and poorly absorbed. In pigs and rats, intact anthocyanins were rarely found in plasma, but metabolites appeared in urine and tissues.

Other findings

Delivery technologies

Micro and nano encapsulation methods, such as ionic gelation and spray-drying, can protect anthocyanins from degradation and improve their release in the gut. These are lab-based techniques.

What the authors conclude

“Many promising outcomes are revealed in support of the benefits of BB interventions in neuroprotection.”
Tran PHL, Tran TTD, 2021

Also in their conclusions

  • They say that frequent blueberry supplementation over long periods and more complex, sensitive tests are needed to fully assess the benefits for healthy brain function.
  • They advise that further studies should determine the best form of blueberry intake, such as whole fruit, powder, drinks or encapsulated forms, for brain health.
  • They note that blueberry leaves also show potential brain health benefits and should be explored further.

How it was done

The authors wanted to gather what is known about blueberries for brain health, from lab tests to human studies, and to explain why anthocyanins are poorly absorbed so readers can make informed choices about daily blueberry consumption.

They reviewed studies of blueberries and their anthocyanins in cells, animals and people, including trials that gave blueberry juice, powder, extract or whole fruit. They also looked at ways to protect anthocyanins during digestion, such as micro and nano encapsulation.

What it can’t tell you

  • Many findings come from lab tests and animals, so they cannot show what happens in people.
  • Human trials were often small and used different forms and doses of blueberries, so results are not consistent.
  • This review cannot show whether blueberries prevent or treat any disease.

The paper

Title
Blueberry Supplementation in Neuronal Health and Protective Technologies for Efficient Delivery of Blueberry Anthocyanins
Type
ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
Evidence
Studies in people · animals · lab
Summarised from
Full text
Cite
Tran PHL, Tran TTD (2021). Blueberry Supplementation in Neuronal Health and Protective Technologies for Efficient Delivery of Blueberry Anthocyanins. Biomolecules. doi:10.3390/biom11010102Free full textPubMed 33466731DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error