Randomised trial · Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme · 2017

Blueberry concentrate and brain blood flow in older adults

What it found

In healthy older adults, 12 weeks of daily blueberry concentrate increased brain activity during a task and blood flow at rest in some brain areas.

Working memory showed only weak evidence of improvement.

What they found

Studies in people

Brain activation

After blueberry supplementation, brain activity increased in several task-related areas compared with placebo. These included Brodmann areas 4/6/10/21/40/44/45, precuneus, anterior cingulate, and insula/thalamus.

Resting brain blood flow

Grey matter perfusion increased in the parietal and occipital lobes after blueberry supplementation but not placebo. There was no change in the frontal lobes for either group.

Working memory

There was weak evidence of improvement in the 2-back working memory test after blueberry versus placebo. The study was not powered to detect changes in cognitive performance.

Other cognitive tests

Performance on several cognitive tests improved over time, but there was no significant difference in improvement between the blueberry and placebo groups.

Blood markers

Serum glutathione decreased in both groups, with a smaller decrease in the blueberry group that was not statistically significant. There were no significant changes in hsCRP or BDNF between groups.

What the authors conclude

“Supplementation with an anthocyanin-rich blueberry concentrate improved brain perfusion and activation in brain areas associated with cognitive function in healthy older adults.”
Bowtell JL, Aboo-Bakkar Z, Conway ME, Adlam AR, Fulford J, 2017

Also in their conclusions

  • They conclude that blueberry concentrate consumed once per day for 12 weeks increased activation of brain areas associated with cognitive processes including memory and executive function.
  • They suggest that these effects appear to be mediated by improved vascular function, as shown by improved resting perfusion of gray matter in the parietal and occipital lobes.

How it was done

Higher flavonoid intakes are linked to slower age-related cognitive decline, but human intervention studies are sparse. The authors wanted to see whether blueberry concentrate improved brain perfusion, task-related activation and cognitive function in healthy older adults.

Twenty-six healthy older adults were randomised to consume either 30 mL blueberry concentrate providing 387 mg anthocyanidins or an isoenergetic placebo daily for 12 weeks. Before and after, they did cognitive tests and a numerical Stroop test in an MRI scanner, and resting brain perfusion was measured.

What it can’t tell you

  • The study was not powered to detect changes in cognitive performance, so it cannot show whether blueberry supplementation improves thinking or memory.
  • Blood samples were not collected in the fasted state and the last supplement dose was at least 24 hours before measurements, so some effects may not have been detected.

The paper

Title
Enhanced task-related brain activation and resting perfusion in healthy older adults after chronic blueberry supplementation
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Full text
Cite
Bowtell JL, Aboo-Bakkar Z, Conway ME, Adlam AR, Fulford J (2017). Enhanced task-related brain activation and resting perfusion in healthy older adults after chronic blueberry supplementation. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. doi:10.1139/apnm-2016-0550Free full textPubMed 28249119DOI

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