Blueberry Intake Does Not Boost Mood in Older Adults
A new pilot study found that daily blueberry powder failed to improve depressive symptoms in adults aged 65 and older.
Updated on Oct. 26, 2026 in Nutrition
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A 2026 pilot study suggests that daily blueberry supplementation changes microbial enzyme functions in the gut of older adults. However, the research found no significant improvement in depressive symptoms for the 18 participants involved.
Why it matters
Researchers are investigating the gut-brain axis to determine if dietary interventions can influence emotional health. Currently, this evidence does not support using blueberries as a treatment for depression.
In a 2026 pilot study of 18 adults aged 65 and older, researchers observed changes in microbial enzyme gene abundance after three months of daily blueberry powder consumption. These findings remain preliminary, as the study detected no significant shifts in bacterial species or mood outcomes.
The players
The Journal of Nutrition
A peer-reviewed scientific publication that covers advances in nutritional research.
The details
The study provided participants with 48 grams of freeze-dried blueberry powder, equivalent to approximately two cups of fresh fruit, to test for systemic impacts. Investigators utilized stool samples to monitor gut microbial activity and validated questionnaires to track depressive symptoms. While researchers identified specific alterations in microbial gene expression, these biological shifts did not translate into a statistically significant improvement in participants' mood compared to the placebo group.
Timeline
2024 studies explored blueberry supplementation and mood in younger and metabolic cohorts.
The pilot study was published in The Journal of Nutrition in August 2026.
Health Landscape
This research is part of the ongoing investigation into the gut-brain axis, which seeks to understand how dietary intake influences emotional health. It follows recent 2024 studies that also found inconsistent or limited evidence regarding blueberries and mood improvement in younger or metabolic-syndrome populations.
While blueberries are a nutrient-dense addition to a balanced diet, there is currently no clinical evidence supporting their use as a targeted treatment for depression. If you are managing depressive symptoms, it is essential to discuss evidence-based treatment options with your physician.
The takeaway
Current research shows that while blueberries may impact specific gut microbial functions, they do not provide a proven mood-boosting effect for older adults. Focus on dietary patterns that support general health and consult a healthcare professional regarding any concerns about depression.
Further reading
For more information on the latest research in diet and well-being, visit Nutrition.
Source note: This article includes information reported by DT News.
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