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Blueberries

Blueberries as a functional food: a randomized trial of wild blueberry powder in older adults, a pregnancy trial combined with fiber, and limits.

Content last updated . This page has not been medically reviewed.

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Overview

Blueberries are rich in anthocyanins, a type of polyphenol. Trials often use freeze-dried blueberry powder, not fresh berries.

What the research shows

  • Older adults: a randomized trial of daily wild blueberry powder, equivalent to 178 g of fresh berries, in healthy older people found improved vascular function and cognitive performance and lower 24-hour ambulatory systolic blood pressure than placebo (by 3.59 mmHg in the trial report). Gut microbiota composition and cerebral blood flow did not change. [1]
  • Pregnancy with obesity: a trial of whole blueberry plus soluble fiber supplementation found less gestational weight gain (6.8 versus 12.0 kg), lower C-reactive protein and lower blood glucose on the glucose challenge test than control, with no change in lipids. [2] Because blueberry and fiber were given together, the effect cannot be assigned to blueberries alone, and anyone pregnant should ask a clinician before changing diet.

Not shown: whether fresh or frozen berries give the same results as the powder, and long-term disease outcomes. Proper evidence for those was not found.

Safety and individual considerations

  • Blueberries are generally a food; allergy is uncommon but possible.
  • Juice and sweetened dried blueberries can add sugar. See Whole fruit vs juice. [3]

Related

Pomegranate · Fresh, frozen and canned

Frequently asked questions

Are frozen blueberries as good as fresh?

Trials used powder equal to fresh weight; we did not find a berry-form comparison. For vitamins, frozen produce can retain them well (see Preparation). [4]

References

  1. Wood E et al. Wild blueberry (poly)phenols can improve vascular function and cognitive performance in healthy older individuals: a double-blind randomized controlled trial. Am J Clin Nutr 2023. PMID 36972800.
  2. Basu A et al. Dietary Blueberry and Soluble Fiber Supplementation Reduces Risk of Gestational Diabetes in Women with Obesity in a Randomized Controlled Trial. J Nutr 2021. PMID 33693835.
  3. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025. Check the site for the current edition.
  4. Bouzari A et al. Vitamin retention in eight fruits and vegetables: a comparison of refrigerated and frozen storage. J Agric Food Chem 2015. PMID 25526594.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.