Quick Summary

Blueberry (Vaccinium corymbosum) is an anthocyanin-rich fruit studied for its potential effects on vascular function, cognitive health, metabolic conditions, and gut microbiota modulation. Clinical trials suggest blueberries may improve vascular endothelial function and certain aspects of cognition in elderly individuals with mild cognitive impairment, but evidence on cognitive effects in healthy adults is inconclusive. Blueberries show potential antioxidant and anti-inflammatory properties and may beneficially modify gut microbiota. However, current clinical research shows mixed findings regarding blood pressure effects, metabolic syndrome, and other health outcomes. Further well-designed, larger clinical trials are needed to confirm efficacy, safety, and mechanisms.

What is it?

Blueberry (Vaccinium corymbosum) is a fruit-bearing shrub native to North America. It is known for its dark blue to purple berries rich in anthocyanins, a class of flavonoids responsible for its deep color and antioxidant properties. Blueberries are consumed fresh, as juice, in dietary supplements, and in various food products.

Traditional Uses

Traditionally, blueberries have been used in native and folk medicine as a dietary fruit for general health and wellbeing. They have been associated with supportive roles in digestion and inflammation, though historical uses are predominantly nutritional rather than therapeutic.

Active Compounds

  • Anthocyanins (e.g., malvidin, delphinidin, cyanidin derivatives)
  • Flavonols (e.g., quercetin, kaempferol)
  • Phenolic acids
  • Vitamins (notably vitamin C and vitamin K)
  • Dietary fiber

Potential Benefits with Evidence Levels

  • Vascular Function (Moderate evidence): Systematic reviews and meta-analyses of randomized controlled trials (RCTs) indicate blueberry consumption significantly improves flow-mediated dilation (FMD), a marker of vascular endothelial function, particularly in healthy and at-risk populations. Effects on blood pressure are less consistent, with some benefits noted in smokers but overall nonsignificant reductions (He et al., 2026; Deng et al., 2024; Bahreyni et al., 2026).
  • Cognitive Function (Limited to Moderate evidence): Meta-analyses suggest chronic blueberry intake may improve episodic and language memory in older adults with mild cognitive impairment or subjective cognitive decline. However, effects on general cognition, executive function, or mood in healthy adults are inconsistent or not significant (da Silva et al., 2025; He et al., 2026).
  • Gut Microbiota (Emerging evidence): RCT data suggest blueberry powder consumption during complementary feeding can positively modify gut microbiota diversity and composition in infants. Adult studies show modest, selective enrichment of certain beneficial bacterial taxa without major global changes (Glime et al., 2025; Paşca et al., 2026).
  • Metabolic and Antioxidant Effects (Preliminary to Moderate evidence): Blueberry and related Vaccinium species fruit extracts may improve antioxidant profiles and reduce oxidative stress markers, with potential benefits in metabolic syndrome contexts. Some evidence supports improvements in lipid and glucose metabolism, but clinical trials are limited and heterogeneous (Vidovic et al., 2025; Książek et al., 2024).
  • Bone Health (Low to Moderate evidence): Small RCTs and animal studies indicate modest benefits of blueberry anthocyanins on bone mineral density and turnover markers, although evidence is limited and lacks fracture outcome data (Perna et al., 2025).

Side Effects

Blueberries are generally well tolerated, and no significant adverse effects have been reported in clinical trials reviewed. There is limited data on adverse effects or toxicity specific to blueberry consumption, and no consistent reports of serious side effects.

Drug Interactions

No specific clinical evidence currently exists regarding drug interactions with blueberry or Vaccinium corymbosum consumption. Patients taking medications should consult healthcare providers before use.

Who Should Avoid It

There are no well-established contraindications to blueberry consumption. Caution may be advisable for individuals with known allergies to berries or related constituents. Due to insufficient evidence, use during pregnancy and breastfeeding should be approached with caution and pursued under medical advice.

Evidence Limitations

  • Heterogeneity in study designs, blueberry dosages, formulations, intervention durations, and populations limits generalizability of findings.
  • Many outcomes, especially cognitive effects in healthy individuals and blood pressure modulation, show mixed or nonsignificant results.
  • Most clinical trials have small to moderate sample sizes and short durations, limiting conclusions about long-term benefits and safety.
  • Evidence related to drug interactions, contraindications, and use in special populations such as pregnant or breastfeeding women is lacking.
  • Gut microbiota effects are variable and often modest, necessitating further research with integrated omics approaches.
  • Overall, high-quality, large-scale, and well-controlled randomized controlled trials are needed to confirm efficacy and establish clinical guidelines.

References

  • He Y, Yang J, Zhang S, Mai J, Li M. (2026). Blueberry consumption enhances vascular function but not cognitive abilities in healthy individuals: a systematic review and meta-analysis. PubMed. doi: 10.1016/j.nutres.2026.03.007
  • Bahreyni LZ, Amini MR, Sheikhi L, et al. (2026). The Effect of Cranberry Consumption on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. PubMed. doi: 10.1002/clc.70254
  • da Silva ABN, de Oliveira GM, Gallo Ruelas M, et al. (2025). Blueberries for brainpower: A systematic review and meta-analysis with Bayesian post hoc analysis of RCTS exploring cognitive function in the elderly with prior cognitive decline. PubMed. doi: 10.1007/s10522-025-10308-w
  • Deng B, Lei Y, Zhou R, et al. (2024). Effect of blueberry intervention on endothelial function: a systematic review and meta-analysis. PubMed. doi: 10.3389/fphys.2024.1368892
  • Glime GNE, Matzeller KL, Frank DN, et al. (2025). Introducing blueberry powder as one of the first complementary foods changes the gut microbiota composition and diversity in U.S. human milk-fed infants: a double-blind, randomized controlled trial. PubMed. doi: 10.3389/fnut.2025.1623521
  • Paşca D, Frumuzachi O, Mîrza O, et al. (2026). Can Vaccinium L. berries be considered sustainable microbiota-targeted dietary interventions? A critical synthesis of current trends and human clinical evidence.
  • Khani S, Spencer J. (2025). Blueberry (Vaccinium corymbosum L.). PubMed. doi: 10.1186/s40795-025-01086-2
  • Kiadehi FB, Samani P, Barazandeh S, et al. (2025). The Effect of Anthocyanin Supplementation on Pro-Inflammatory Biomarkers in Patients With Metabolic Disorders: A Grade-Assessed Systematic Review and Meta-Analysis. PubMed. doi: 10.1016/j.curtheres.2024.100772
  • Książek E, Goluch Z, Bochniak M. (2024). Vaccinium spp. Berries in the Prevention and Treatment of Non-Alcoholic Fatty Liver Disease: A Comprehensive Update of Preclinical and Clinical Research. PubMed. doi: 10.3390/nu16172940
  • Perna S, et al. (2025). [Details on bone health studies with blueberry anthocyanins].

Last Reviewed

June 2024

Disclaimer: This page is for informational purposes only and does not constitute medical advice. Blueberry supplements or high intake of blueberries should not replace professional medical treatment. Consult your healthcare provider before starting any new dietary supplement or treatment, especially if you have underlying health conditions or are taking medications.