Randomised trial · Nutrients · 2025Conflicts declared

Blueberry powder in infancy and allergy symptoms

What it found

In breastfed infants given blueberry powder from 5 to 12 months, allergy-related symptoms were more likely to clear up than in infants given a placebo.

Levels of an inflammation-linked immune marker also fell more in the blueberry group.

What they found

Studies in people

Allergy symptom changes

More infants in the blueberry group had allergy-related symptoms at the start, but their symptoms improved more over the study. By the end, 14% of the blueberry group had their breathing symptoms clear up, and fewer new symptoms appeared compared with the placebo group.

Immune marker IL-13

The blueberry group had a bigger drop in IL-13, a marker linked to allergic inflammation, than the placebo group. This difference was statistically significant in one analysis.

Immune marker IL-10

IL-10, a marker linked to immune tolerance, went up more in the blueberry group than in the placebo group, but the difference was borderline.

Gut bacteria links

At 12 months, certain gut bacteria were linked to levels of IL-10 and IL-13. For example, higher Blautia was linked to lower IL-10, while higher Lactobacillus was linked to higher IL-10.

Symptom and marker link

Changes in allergy symptoms were not significantly linked to changes in IL-10 or IL-13 levels across the whole group.

What the authors conclude

“The consumptio9n of blueberries as an early complementary food may improve resolution of allergy symptoms, modulate immune biomarkers, and promote beneficial shifts in gut microbiota during infancy.”
Venter C, Boden S, Pickett-Nairne K, et al, 2025

Also in their conclusions

  • They say that eating blueberries as an early complementary food may help allergy symptoms clear up, change immune markers, and shift gut bacteria in infancy.
  • They advise that future research should identify which parts of blueberries cause these effects and test other similar foods.
  • They note that larger studies with more detailed microbe testing and follow-up beyond the first year are needed.

How it was done

Allergic symptoms often appear in the first year of life, but it is unclear how specific foods like fruits affect infant allergy symptoms, inflammation, immunity and gut bacteria.

They randomly assigned 76 breastfed infants in the Denver area to receive up to 10 g per day of freeze-dried blueberry powder or a matching placebo powder from 5 to 12 months of age. Stool, blood and caregiver-reported allergy symptom data were collected at the start and end of the study.

What it can’t tell you

  • The study was small and not designed to prove that blueberry powder prevents allergies or changes the immune system in the long term.
  • The results cannot show whether the effects last beyond 12 months of age or whether whole fresh blueberries would have the same impact.

The paper

Title
Blueberry Consumption in Early Life and Its Effects on Allergy, Immune Biomarkers, and Their Association with the Gut Microbiome
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Full text
Cite
Venter C, Boden S, Pickett-Nairne K, et al (2025). Blueberry Consumption in Early Life and Its Effects on Allergy, Immune Biomarkers, and Their Association with the Gut Microbiome. Nutrients. doi:10.3390/nu17172795Free full textPubMed 40944184DOI

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