Blueberries: Nutrition, Benefits and Frozen Blueberries

Blueberries are small, sweet-tart berries of the Vaccinium family, and a cup of raw blueberries has about 84 calories, 3.6 grams of fiber and a quarter of the Daily Value for vitamin K in USDA data. Their deep blue color comes from anthocyanins, plant pigments that are the focus of most blueberry research. This guide covers blueberry nutrition from the USDA database, what systematic reviews of human trials actually found about blueberries benefits, how frozen blueberries compare with fresh, and the food-safety facts behind frozen berry outbreaks.

Peptide Labs does not sell blueberries or blueberry products. This article is general nutrition information, not medical advice.

Blueberry nutrition per cup

In USDA SR Legacy data, blueberries are mostly water (about 84 grams per 100 grams) with natural sugar, fiber, vitamin C, vitamin K and manganese. They are low in protein and fat and have almost no sodium. Here is how the common forms compare, per USDA serving:

A cup of raw blueberries also gives about 22% of the Daily Value for manganese and 9% for copper, per USDA. Wild blueberries are smaller and more intensely colored; the only wild entry in SR Legacy (wild blueberries, raw, Alaska Native, FDC 167640) lists about twice the vitamin C and several times the manganese of cultivated berries per 100 grams, but that entry comes from one region, so read it as a rough comparison.

Blueberries compared with other berries

Per cup, USDA lists raspberries at 64 calories and 8.0 grams of fiber, strawberries at 49 calories with almost a full day’s vitamin C, and blueberries at 84 calories with more vitamin K than either. Each berry brings something different. See our guides to raspberries and strawberries, our high-fiber foods list, and our guide to sugar levels across fruits.

Anthocyanins: what makes blueberries blue

Anthocyanins are water-soluble pigments in the flavonoid family that give blueberries, blackberries, grapes and red cabbage their blue, purple and red shades. They are the reason blueberry research so often mentions antioxidants. A test-tube antioxidant result, however, does not show what happens in the body, which is why the reviews below focus on measurable outcomes in people, such as blood pressure, blood vessel function and memory tests.

USDA SR Legacy does not list anthocyanin amounts, so this guide gives no numbers for them. Our guide to antioxidants in food explains why antioxidant test-tube scores do not translate directly into health effects, and our superfoods guide looks at the marketing label often attached to blueberries.

Blueberries benefits: what systematic reviews found

Many small randomized trials have tested blueberries, usually as freeze-dried blueberry powder or whole berries, against a placebo powder. Systematic reviews pool those trials. Their findings are modest and not all in the same direction:

• Blood vessel function: a 2026 meta-analysis of 14 randomized trials with 632 healthy people found blueberries improved flow-mediated dilation, an ultrasound test of how well an artery widens, by about 1.1 percentage points. A 2024 meta-analysis of 11 trials reported a similar improvement, though the trials varied a lot.
• Blood pressure: results conflict. The 2026 review found no significant change in systolic or diastolic pressure in healthy people. The 2024 review found a small drop in diastolic pressure (about 2.2 mmHg) but not in systolic pressure.
• Metabolic markers: a 2022 meta-analysis of 21 trials found no significant effect on waist size, BMI, HbA1c, fasting glucose or insulin resistance, while reporting changes in blood pressure, triglycerides and cholesterol fractions.
• Memory and mood: in healthy people, the 2026 review found no significant effect on executive function or mood. A 2025 review of 9 trials in 513 older adults with mild cognitive impairment or self-reported memory decline found a small improvement in episodic memory but not in other memory tests, and its authors called for larger trials.
• Gut health: a 2023 systematic review of 16 studies, many of them in animals, described changes in gut bacteria and gut barrier markers and noted significant gaps in the evidence.

The fair summary: blueberries are a nutritious fruit, and the strongest signal from trials is a small effect on a blood vessel function test. Most trials are short and small, many used concentrated powders rather than whole fruit, and the reviews describe wide differences between studies. None of this shows that blueberries ward off any disease.

Frozen blueberries: nutrition and safety

Frozen blueberries are picked and frozen, so plain frozen berries stay close to fresh in calories, fiber and vitamin K in USDA data. Vitamin C is lower in the USDA frozen entry (4% vs 16% DV per cup). The bigger difference is added sugar: the sweetened frozen entry has more than three times the sugar per cup, and sweetened dried blueberries pack 27 grams of sugar into a quarter cup. The ingredient list tells you whether sugar or juice was added.

Frozen berries carry a food-safety issue that matters because they are often eaten without heating, for example in smoothies. A report in CDC’s Emerging Infectious Diseases journal described 24 hepatitis A cases in the Netherlands from November 2024 to February 2025 traced to one batch of frozen blueberries from a single grower, sold by one supermarket chain; 8 people were hospitalized and there were no deaths. The authors point to manual harvesting and eating berries without heating as the reasons berries can spread the virus.

FDA tested 1,558 samples of frozen strawberries, raspberries and blackberries from 2018 to 2023 and found hepatitis A virus or norovirus in fewer than 1% of samples for each berry type, with no meaningful difference between domestic and imported berries. Blueberries were not part of that sampling. Practical steps:

• Watch for recall notices on frozen fruit, and follow them if a product you have is listed.
• Wash fresh berries under running water just before eating, without soap or produce washes, as FDA advises, and refrigerate them.
• If you feel unwell after eating a recalled product, contact a clinician and mention the recall.

Who should be careful with blueberries

• Warfarin users: blueberries supply a fair amount of vitamin K. The NIH Office of Dietary Supplements advises people on warfarin to keep vitamin K intake consistent rather than avoid it; see our vitamin K foods guide and talk to your clinician.
• Allergy: blueberries are not one of the nine major food allergens on US labels, but any food can cause a reaction. Hives, swelling or breathing trouble needs urgent care; our elimination diet guide explains why testing should be supervised.

Looking for a lower-calorie, very watery fruit for summer? Our guide to watermelon covers its nutrition and cut-melon safety.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Watermelon: Benefits, Nutrition, Lycopene and Citrulline, Foods High in Antioxidants: USDA Chart and What the Science Says, Low Sugar Fruits: USDA Sugar per Serving, From Lowest to Highest, Cranberries: Nutrition, Dried Cranberries and What Research Shows, Types of Berries: Kitchen Names, Botany and USDA Nutrients.