BlueberriesOther

Q: Why do blueberries have a white powdery coating on them?

That coating is called 'bloom' — a natural wax the fruit produces on its own, not pesticide residue, mold, or dirt. A 2023 study in *Plants, People, Planet* found something surprising: blueberries aren't actually blue underneath. Their color comes from the wax coating's disordered, light-scattering microstructure, not from a blue pigment. Strip the wax off, and the berry underneath looks black, with anthocyanin juice that's actually deep red. The same mechanism explains the blue color of other bloom-coated fruits, like plums and Oregon grapes.

kcal / 100g

kcal / 1 cup

4 things to watch for

High-ProteinKetoLow-CalorieLow-Sugar

Dairy-FreeEgg-FreeGluten-FreeLow-CarbLow-FatNut-FreePalm Oil FreeSoy-FreeVeganVegetarian

Informational only, not medical advice. Always verify against the physical product label — data may be incomplete or out of date.

Nutrition Facts (per 100g)

Nutrient	Amount	%DV
Energy	57kcal	—
Protein	0.74g	1%
Total lipid (fat)	0.33g	0%
Fatty acids, total saturated	0.028g	0%
Cholesterol	0mg	0%
Carbohydrate, by difference	14.49g	5%
Fiber, total dietary	2.4g	9%
Total Sugars	9.96g	—
Sodium, Na	1mg	0%

Vitamins & Minerals

Calcium, Ca6mg (1% NRV)

Iron, Fe0.28mg (2% NRV)

Potassium, K77mg (4% NRV)

Magnesium, Mg6mg (2% NRV)

Phosphorus, P12mg (2% NRV)

Zinc, Zn0.16mg (2% NRV)

Copper, Cu0.057mg (6% NRV)

Manganese, Mn

Manganese contributes to normal energy-yielding metabolism EU register →

Manganese contributes to the maintenance of normal bones EU register →

Manganese contributes to the normal formation of connective tissue EU register →

Manganese contributes to the protection of cells from oxidative stress EU register →

0.336mg (17% NRV)

Selenium, Se0.1µg (0% NRV)

Vitamin A, RAE3µg (0% NRV)

Vitamin C, total ascorbic acid9.7mg (12% NRV)

Vitamin D (D2 + D3)0µg (0% NRV)

Vitamin E (alpha-tocopherol)0.57mg (5% NRV)

Vitamin K (phylloquinone)

Vitamin K contributes to normal blood clotting EU register →

Vitamin K contributes to the maintenance of normal bones EU register →

19.3µg (26% NRV)

Thiamin0.037mg (3% NRV)

Riboflavin0.041mg (3% NRV)

Niacin0.418mg (3% NRV)

Vitamin B-60.052mg (4% NRV)

Folate, total6µg (3% NRV)

Vitamin B-120µg (0% NRV)

Diet Compatibility

VeganYes
Yes — Blueberries is vegan.
Based on Open Food Facts ingredient analysis. How we set this
VegetarianYes
Yes — Blueberries is vegetarian.
Based on Open Food Facts ingredient analysis. How we set this
Palm Oil FreeYes
Yes — Blueberries is palm oil free.
Based on Open Food Facts ingredient analysis. How we set this
Gluten-FreeYes
Yes — Blueberries is gluten-free.
Based on the ingredient list and allergen data recorded in Open Food Facts. How we set this
Dairy-FreeYes
Yes — Blueberries is dairy-free.
Based on the ingredient list and allergen data recorded in Open Food Facts. How we set this
Nut-FreeYes
Yes — Blueberries is nut-free.
Based on the ingredient list and allergen data recorded in Open Food Facts (covers tree nuts and peanuts). How we set this
Soy-FreeYes
Yes — Blueberries is soy-free.
Based on the ingredient list and allergen data recorded in Open Food Facts. How we set this
Egg-FreeYes
Yes — Blueberries is egg-free.
Based on the ingredient list and allergen data recorded in Open Food Facts. How we set this
KetoNo
No — Blueberries is not keto-friendly (12.09 g net carbs per 100g, over the ≤10 g net carbs bar). (may not account for sugar alcohols; per-100g basis is a rougher heuristic than per-serving.)
≤5g net carbs per serving — our bar, not a regulatory standard. How we set this
Low-CarbYes
Yes — Blueberries is low-carb (12.09 g net carbs per 100g, within the ≤15 g net carbs bar). (may not account for sugar alcohols.)
≤15g net carbs per serving — our bar, not a regulatory standard. How we set this
Low-SugarNo
No — Blueberries is not low in sugar (9.96 g sugar per 100g, over the ≤5 g sugar bar).
≤5g sugar per serving — our own criterion; the FDA defines none. How we set this
High-ProteinNo
No — Blueberries is not high in protein (0.74 g protein per 100g, below the ≥10 g protein bar).
≥10g protein per serving — FDA 21 CFR 101.54 (≥20% DV). How we set this
Low-FatYes
Yes — Blueberries is low-fat (0.33 g fat per 100g, within the ≤3 g fat bar).
≤3g fat per serving — FDA 21 CFR 101.62. How we set this
Low-CalorieNo
No — Blueberries is not low-calorie (57 kcal per 100g, over the ≤40 kcal bar).
≤40 kcal per serving — FDA 21 CFR 101.60. How we set this

Read the sourced research

Raw blueberries carry 14.5g total carbohydrate per 100g, the baseline USDA figure used for keto assessment. ^[6]
A keto-sized 1/2-cup (74g) portion works out to about 9g net carbs, per Healthline. ^[7]
Blueberries got a reclassification in 2022: Monash University's retest puts the low-FODMAP serving at a full 150g (about 1 cup), reportedly staying low-FODMAP up to 500g.

Note: a different testing body, the FODMAP Friendly app, caps its own low-FODMAP serving lower, at 300g.

Both agree blueberries moved from high- to low-FODMAP after the 2022 retest — they just don't agree on the upper limit. Flagged, not resolved. ^[8]
Among people with birch-pollen-linked oral allergy syndrome, about 8% report blueberries as a trigger food, per a surveyed patient cohort. ^[9]

Health Benefits

Blueberries have a glycemic index of 53, per Cleveland Clinic — solidly in the moderate range, not a low-GI or high-GI food.

That makes them a reasonable fruit choice for people watching blood sugar, alongside their fiber and antioxidant content. ^[1]
In a 12-week trial published in the Journal of Agricultural and Food Chemistry, older adults drinking wild blueberry juice showed improved paired-associate learning (p=0.009) and better word-list recall (p=0.04), per Krikorian and colleagues.

Both results were statistically significant, though this was a single small trial, not a large-scale confirmation. ^[2]
A King's College London randomized trial had participants drink the equivalent of 200g of wild blueberries a day for one month to study vascular function.

The dose-dependent results suggested a real link between blueberry intake and blood vessel function, though this was one trial over a short period. ^[3]
The longest blueberry trial to date ran for 6 months, giving participants with metabolic syndrome 150g of blueberries daily (about 1 cup).

Researchers found improvements in cardiometabolic biomarkers over that period — a meaningfully longer test than most blueberry studies run. ^[4]

Storage & Buying Tips

Freezing blueberries barely touches their antioxidant content: anthocyanin levels showed no significant change after 3 months frozen at -20°C, compared to fresh berries.

Drying is a different story — cabinet-drying alone lost 41% of anthocyanins, and drying with an osmotic pretreatment step lost even more, 49%. ^[5]

Frequently Asked Questions

Are blueberries safe to eat during pregnancy?

Yes. We found no government or academic source that flags blueberries specifically as a pregnancy risk.

The UK NHS's pregnancy nutrition guidance lists most fruits and vegetables — washed thoroughly — as safe to eat during pregnancy. The main food-safety concern with fresh produce generally is soil-borne toxoplasma, and washing addresses that; it isn't a blueberry-specific issue.

Blueberries' nutrient profile — folate, fiber, potassium, and vitamin C, per USDA data — also fits comfortably within general prenatal guidance to eat a variety of fruit daily. ^[10]

How many blueberries should I eat per day?

There's no official recommended daily amount for blueberries. Research trials use varying doses depending on what they're testing.

Studies that found cardiovascular or metabolic benefits typically used 150–200 g/day — roughly one cup — sustained over weeks to months. A separate 6-week insulin-sensitivity trial used the equivalent of about 45 g/day of blueberry bioactives, delivered via smoothie.

These are research doses, though, not formal dietary recommendations — there's no upper limit established by this evidence either. ^[4]

Are blueberries low in sugar and safe for diabetics?

Blueberries have a relatively low glycemic index of around 53, and per USDA data, about 9.96 g of total sugar per 100 g. Their fiber and low sugar density mean they raise blood sugar more slowly than high-GI foods.

Cleveland Clinic cites a study finding daily blueberry consumption lowered heart-health markers like triglycerides in men with type 2 diabetes. A broader 2016 evidence review, though, concluded more research is still needed on blueberries and insulin resistance specifically — the picture isn't fully settled. ^[6]

Why do blueberries have a white powdery coating on them?

That coating is called 'bloom' — a natural wax the fruit produces on its own, not pesticide residue, mold, or dirt.

A 2023 study in Plants, People, Planet found something surprising: blueberries aren't actually blue underneath. Their color comes from the wax coating's disordered, light-scattering microstructure, not from a blue pigment.

Strip the wax off, and the berry underneath looks black, with anthocyanin juice that's actually deep red. The same mechanism explains the blue color of other bloom-coated fruits, like plums and Oregon grapes. ^[11]

Found in these products

4 products in our database contain Blueberries.

Sources & Last Updated

Nutrition data: USDA FoodData Central, “Blueberries, raw” (SR Legacy, fdcId 171711), updated 2026-08-27.

Research reviewed 2026-08-21.

BlueberriesOther

Nutrition Facts (per 100g)

Vitamins & Minerals

Diet Compatibility

Health Benefits

Storage & Buying Tips

Frequently Asked Questions

Are blueberries safe to eat during pregnancy?

How many blueberries should I eat per day?

Are blueberries low in sugar and safe for diabetics?

Why do blueberries have a white powdery coating on them?

Found in these products

Blueberry Rxbar

Fig Bar Blueberry

Belvita Crunchy Blueberry Breakfast Biscuits

Mixed Berry Vanilla Protein Shake

Sources & Last Updated

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