Blueberry powder and thinking in middle-aged adults
What it found
In a 12-week trial in overweight middle-aged people with memory complaints, daily blueberry powder improved some thinking tasks and lowered fasting insulin.
The authors say this suggests a possible way to protect against later cognitive decline.
What they found
Studies in people
Word finding
The blueberry group did better on a test of rapid word production for words starting with certain letters. There was no difference for producing words in a category.
Memory interference
The blueberry group made fewer intrusion errors on a memory test, meaning they were less likely to recall wrong words. Other memory measures like learning and delayed recall did not differ.
Everyday memory
People in the blueberry group reported fewer problems with memory encoding in daily life, such as misplacing things. The overall memory complaint score showed a trend in the same direction.
Fasting insulin
Fasting insulin dropped in the blueberry group compared to placebo, from 10.2 to 8.3 µU/mL. There was no change in blood sugar, glycated hemoglobin, or other metabolic markers.
Mitochondrial function
In a subset of 17 people, there was a trend toward increased mitochondrial uncoupling in the blueberry group. The difference in state III respiration was not statistically confirmed.
Diet and mood
Background intake of anthocyanins from other foods did not change during the study. Mood symptoms were low and did not change in either group.
What the authors conclude
“In summary, this study demonstrated that blueberry supplementation has neurocognitive benefit in middle-aged individuals with insulin resistance and elevated risk for future dementia.”
Also in their conclusions
- They conclude that blueberry supplementation has neurocognitive benefit in middle-aged individuals with insulin resistance and elevated risk for future dementia.
- They suggest that ongoing blueberry intake may protect against future neurocognitive decline in vulnerable individuals.
- They call for future research over longer periods with longitudinal cognitive assessments to assess influence on progression of cognitive decline and to investigate mechanisms further.
How it was done
Late-life dementia develops over many years, and metabolic problems like insulin resistance in midlife are a risk factor. The authors wanted to see if blueberry supplementation could improve cognition and metabolism in people at higher risk.
They randomly assigned 33 overweight men and women aged 50 to 65 with subjective cognitive decline to daily blueberry powder (equal to 0.5 cup whole fruit) or a placebo powder for 12 weeks. They measured thinking, mood, blood markers, and other factors before and after.
What it can’t tell you
- The study was small, with only 33 people enrolled and some dropouts, so the results may not apply to everyone.
- It lasted only 12 weeks, so it cannot show whether these benefits last or prevent dementia later in life.
- The trial cannot prove that blueberry powder caused the improvements, only that they were linked in this group.
Who paid
- Funding
- Funded by NINDS NIH HHS (from the PubMed record).
- Conflicts
- The authors declare no conflict of interest. The funding organization had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
- Authors work at
- University of Cincinnati Academic Health Center, USA; Cincinnati Children's Research Foundation, USA; Cincinnati Children's Hospital Medical Center, USA
The paper
- Title
- Blueberry Supplementation in Midlife for Dementia Risk Reduction
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Krikorian R, Skelton MR, Summer SS, Shidler MD, Sullivan PG (2022). Blueberry Supplementation in Midlife for Dementia Risk Reduction. Nutrients. doi:10.3390/nu14081619Free full textPubMed 35458181DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error