Blueberry powder and depression and anxiety symptoms in rural Louisiana
What it found
In a small randomised trial in people with depression or anxiety, 12 weeks of daily blueberry powder reduced symptoms on two rating scales compared with placebo.
The authors say the results need confirming in larger studies.
What they found
Studies in people
Depression symptoms
On the Hamilton Depression Rating Scale, blueberry was better than placebo at reducing symptoms from the start to the end of treatment. The difference was 3.69 points, which is within the range considered clinically important for this scale.
Anxiety symptoms
On the GAD-7 anxiety questionnaire, blueberry was better than placebo at reducing symptoms from the start to the end of treatment. The difference was 3.13 points, just short of the 4-point threshold for clinical importance.
No effect at 6 weeks
There was no significant difference between blueberry and placebo at the 6-week midpoint for depression or anxiety scores.
Self-rated depression
On the self-rated Major Depression Inventory, there was no significant difference between blueberry and placebo.
Inflammation markers
Levels of CRP and the inflammatory cytokines IL-1β, IL-6, TNF-α, IFN-γ and IL-10 were not affected by blueberry compared with placebo.
Metabolites in blood
In an exploratory analysis of blood metabolites, some changes were seen in the blueberry group, but the authors say these results are tentative and need larger studies to confirm.
What the authors conclude
“Overall, this study found potential improvements in symptoms of depression and anxiety following daily blueberry supplementation, although the biochemical mechanisms underlying these behavioral improvements remain unresolved.”
Also in their conclusions
- They say the behavioural results support the idea that blueberry supplementation is more effective than placebo at reducing symptoms of anxiety and depression.
- They stress that the findings must be replicated in larger and more diverse populations before strong conclusions can be drawn.
- They suggest future studies should test blueberries in men, in people not taking psychiatric medicines, and over longer periods.
How it was done
The authors wanted to test a simple, accessible nutritional approach for depression and anxiety in rural areas, where specialist mental health care is often limited. They also wanted to see if a study like this could be run in rural health clinics.
They recruited adults in rural Louisiana with a diagnosis of major depressive disorder or generalised anxiety disorder. In a double-blind crossover trial, 24 g of freeze-dried blueberry powder or a matched placebo was taken daily for 12 weeks, with a 4-week washout between the two periods. Symptoms were scored at the start, middle and end of each period.
What it can’t tell you
- The study was small and mostly included middle-aged women, so the results may not apply to other groups.
- Most participants were already taking medication for depression or anxiety, so it is not clear how blueberries would work on their own.
- The trial cannot show whether the improvements would last beyond the 12-week treatment period.
Who paid
- Funding
- Funded by NIH HHS; NINDS NIH HHS; NIDCD NIH HHS; USHBC (from the PubMed record).
- Conflicts
- Author A.J. was employed with the company Louisiana Health Practitioners LLC. Author S.J. was employed with the company Renal Associates of Louisiana LLC. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Authors work at
- Louisiana State University, USA
The paper
- Title
- Effects of Blueberry Supplementation on Depression and Anxiety Symptoms in a Rural Louisiana Population
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Venable KE, Kelley DP, Jeansonne A, et al (2025). Effects of Blueberry Supplementation on Depression and Anxiety Symptoms in a Rural Louisiana Population. Nutrients. doi:10.3390/nu17233720Free full textPubMed 41374012DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error