Blueberry, Vaccinium corymbosum (Ericaceae)

Vaccinium corymbosum, commonly known as highbush blueberry and commercialised simply as blueberry, is a deciduous shrub of the family Ericaceae, native to eastern North America. In its natural habitats it forms dense thickets that can exceed two metres in height, typically in acidic, well-drained but moist soils of forest edges, open woodlands and wetlands rich in organic matter. The leaves are dark green and glossy during the growing season and turn intense red, orange or purple shades in autumn, giving the species considerable ornamental value. The small, urn-shaped flowers, white or very pale pink and borne in corymbose inflorescences, are characteristic of the genus Vaccinium and provide an important early nectar source for pollinating insects.

The fruit is a blue to blue-black berry covered with a thin waxy bloom, typically larger than the European bilberry (Vaccinium myrtillus). A key difference from wild European bilberry lies in the distribution of pigments: in cultivated highbush blueberry, anthocyanins are concentrated mainly in the skin, while the pulp remains pale, with juice that is much less deeply coloured. This anatomical distribution influences the total anthocyanin content per unit of fresh weight and partly explains the quantitative differences observed among Vaccinium species. Vaccinium corymbosum is tetraploid and usually requires a substantial amount of winter chilling for optimal flowering and fruit set, a requirement that has strongly oriented breeding programmes towards the development of cultivars adapted to different climatic zones.

From an ecological standpoint, highbush blueberry plays a significant role in acidic wetland and forest ecosystems of North America. Its berries are an important food resource for birds and mammals of various sizes, contributing to seed dispersal and energy flow in these habitats. At the same time, the species has been extensively domesticated and cultivated, becoming the primary model of cultivated blueberry worldwide. Blueberry plantations enhance crop diversification in temperate regions but also raise issues related to soil management, the use of acidifying amendments, and the preservation of biodiversity in intensively managed agricultural landscapes.

From a chemical, nutritional and health perspective, highbush blueberries are rich in polyphenols, especially anthocyanins, which form the main class of pigments responsible for the blue-violet colour and a substantial proportion of the fruit’s antioxidant activity. Multiple anthocyanin structures (derivatives of delphinidin, cyanidin, petunidin, peonidin and malvidin) are present, together with flavonols, phenolic acids and other phytochemicals, creating a complex bioactive profile. Alongside the phenolic fraction, blueberries supply vitamin C, dietary fibre, a moderate amount of simple sugars and relatively low energy density, characteristics that support their inclusion in balanced dietary patterns.

A large body of research has examined the potential health-related applications of blueberry consumption. Human and experimental studies indicate that regular intake of blueberries or anthocyanin-rich extracts may contribute to improvements in various cardiometabolic markers, including aspects of endothelial function, blood pressure regulation, lipid profile and insulin sensitivity, as well as to reductions in certain oxidative and inflammatory biomarkers. Other lines of investigation explore possible effects on cognitive function and brain ageing, vascular and neurovascular function, and gut–microbiota interactions, where blueberry polyphenols appear to modulate both microbial composition and metabolic responses. Although results are generally encouraging, they derive from studies with specific doses, formulations and study designs, and therefore cannot be directly generalised to all consumption patterns.

It is essential to distinguish between the dietary use of blueberries as a whole fruit, an approach that is broadly considered safe and nutritionally favourable, and the use of concentrated preparations (standardised extracts, high-dose supplements). The latter require careful evaluation in terms of standardisation, dosage, duration of intake and possible interactions with pharmacological therapies, particularly in individuals with chronic conditions such as type 2 diabetes, hypertension or dyslipidaemia. In these contexts, blueberry-based nutraceuticals should be viewed, if used at all, as adjuncts rather than replacements for evidence-based medical treatments.

From an agronomic and commercial point of view, Vaccinium corymbosum stands at the centre of intense cultivar development, aimed at improving yield, fruit quality, resistance to biotic and abiotic stresses and adaptation to a wide range of environmental conditions. Modern cultivars differ in ripening time, berry size, anthocyanin content, texture and shelf life, parameters that affect both the intended use (fresh consumption versus processing) and the nutritional potential. At the same time, post-harvest technologies and processing methods are being optimised to preserve phenolic content and antioxidant capacity during storage, freezing and industrial transformation, given their importance for the overall value of the product along the supply chain.

Botanical classification (APG IV system)

Indicative nutritional values per 100 g (fresh highbush blueberries)
Values refer to fresh cultivated blueberries (blueberries, raw) and may vary with cultivar, growing conditions and ripeness.

At typical serving sizes (around 50–100 g of fruits, for example in yogurt, fruit salads, baked goods or as a snack), cultivated blueberries provide a moderate energy intake, almost entirely from carbohydrates, together with an interesting contribution of dietary fiber, vitamin C, vitamin K, and phenolic compounds (anthocyanins and other polyphenols), which are more relevant from a phytochemical than from a macronutrient perspective.

Lipid profile note

Fresh fruits of Vaccinium corymbosum have a very low fat content. Saturated fatty acids (SFA) are present only in minimal amounts; when SFA predominate over unsaturated fats in the overall diet, they are generally considered less favourable for cardiovascular health.

Most of the small lipid fraction is composed of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), which are usually regarded as more favourable when they replace part of dietary SFA. However, because the absolute fat content of blueberries and the typical serving sizes are both low, their direct impact on total dietary fat balance is negligible; nutritional interest focuses mainly on carbohydrates, fiber, vitamins and phenolic compounds.

Cultivation:

• Soil: Prefers acidic, well-drained soils with a pH of 4.5 to 5.5. It thrives in sandy, loamy, or peaty soils.
• Climate: Grows well in temperate climates with cold winters and cool summers. It requires a period of winter chill for proper fruiting.
• Irrigation: Regular watering is necessary, especially during dry periods, but avoid overwatering to prevent root rot.
• Fertilization: Use low-phosphorus fertilizers, as lowbush blueberries are adapted to low-phosphorus soils. An acidic, balanced fertilizer can be applied in the spring.
• Pruning: Pruning helps to maintain plant shape and stimulate new growth. Remove old or damaged branches to improve air circulation and fruit yield.

Uses and Benefits:

• Culinary Uses: blueberries are used in a variety of culinary applications, including jams, pies, juices, and baked goods. They are enjoyed fresh, frozen, or dried.
• Medicinal Uses: These berries are valued for their potential health benefits, including improved cognitive function, reduced inflammation, and enhanced cardiovascular health. They are often used in dietary supplements and traditional remedies.
• Cosmetic Uses: Extracts from lowbush blueberries are incorporated into skincare products for their antioxidant properties, which can help protect the skin from oxidative stress and promote a youthful appearance.

INCI Functions:

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

Cosmetic astringent. This ingredient exerts a direct effect on the skin by tightening dilated pores by contracting stratum corneum cells and removing superfluous oil.

Hair conditioning agent. A significant number of ingredients with specific and targeted purposes may co-exist in hair shampoo formulations: cleansers, conditioners, thickeners, matting agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersants that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioning agents includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners. They can perform their task generally accompanied by other different ingredients.

Nail Conditioning agent. It is an agent that creates protection against harmful or chemical substances by strengthening the nail structure against external elements and can repair any chipping, cracking or brittle nails. It helps keep the nail's outer layer and keratin protein in good condition. It can also prevent cracking and peeling of the nail.

Antioxidant agent. Ingredient that counteracts oxidative stress and prevents cell damage. Free radicals, pathological inflammatory processes, reactive nitrogen species and reactive oxygen species are responsible for the ageing process and many diseases caused by oxidation.

CAS: 84082-34-8   EC number 281-983-5

Applications:

• Food Industry: Blueberries are used to make a wide range of food products, including jams, sauces, and baked goods. Their flavor and nutritional profile make them a popular choice.
• Pharmaceutical Industry: Blueberry extracts are used in dietary supplements and herbal remedies due to their potential benefits for brain health, cardiovascular health, and overall well-being.
• Cosmetic Industry: Ingredients derived from lowbush blueberries are used in skincare products for their antioxidant and anti-inflammatory effects, helping to improve skin health and appearance.

Environmental and Safety Considerations:

• Environmental Impact: Cultivating blueberries in an environmentally sustainable way is important to minimize impacts on soil and local ecosystems. Organic farming practices and responsible water use are recommended.
• Safety: Lowbush blueberries are generally safe for consumption and use.

Studies

Blueberry contains a large number of phytochemicals including flavonoids, polyphenols and anthocyanins to which the scientific literature attributes a positive role in limiting the risks of cardiovascular disease, obesity and type 2 diabetes mellitus as they exert antioxidant and anti-inflammatory activity. It can therefore be considered a nutraceutical.

This crossover study conducted on obese or overweight patients with metabolic syndrome confirmed an antioxidant action that manifested itself after three hours from the intake of blueberries during meals (1).

The most abundant flavonoids found in blueberry are, according to this study, quercetin, kaempferol and, among phenolic acids, gentisic acid. These compounds were evaluated on treated cells HCT-116, a tumor model for human colon cancer. Quercetin and kaempferol have shown strong cytotoxic, antioxidant and apoptotic effects, while gentisic acid is mostly effective as an antioxidant polyphenol. The study concludes that these flavonoids have anticancer potential (2).

Based on evidence, blueberry can improve some measures of cognitive performance and mood (3).

In blueberry content, 10.0 μg/mL of phenolic acid present in blueberry has been shown to inhibit the death of retinal pigment epithelial cells. Anthocyanins and flavonoids showed similar results and the consistent activity of flavonoids improved phagocytosis and oxidative cellular stress (4).

An intake of blueberry flavonoids, equivalent to 240 g or 1½ cup of fresh blueberries, can provide acute cognitive benefits in children. These results support the accumulation of evidence that flavonoid-rich products are beneficial to healthy brain function, particularly during critical developmental periods (5).

Blueberry studies

References__________________________________________________________________

(1) Sobolev AP, Ciampa A, Ingallina C, Mannina L, Capitani D, Ernesti I, Maggi E, Businaro R, Del Ben M, Engel P, Giusti AM, Donini LM, Pinto A. Blueberry-Based Meals for Obese Patients with Metabolic Syndrome: A Multidisciplinary Metabolomic Pilot Study. Metabolites. 2019 Jul 10;9(7):138. doi: 10.3390/metabo9070138.

Abstract. A pilot study was carried out on five obese/overweight patients suffering from metabolic syndrome, with the aim to evaluate postprandial effects of high fat/high glycemic load meals enriched by blueberries. Postprandial urine samples were analyzed by 1H-NMR spectroscopy after 2 and 4 h from ingestion to identify potential markers of blueberry intake. Significant decrease of methylamines, acetoacetate, acetone and succinate, known indicators of type 2 diabetes mellitus, were observed after the intake of meals enriched with blueberries. On the other hand, an accumulation of p-hydroxyphenyl-acetic acid and 3-(3'-hydroxyphenyl)-3-hydropropionic acid originating from gut microbial dehydrogenation of proanthocyanidins and procyanidins was detected. Real-time PCR-analysis of mRNAs obtained from mononuclear blood cells showed significant changes in cytokine gene expression levels after meals integrated with blueberries. In particular, the mRNAs expression of interleukin-6 (IL-6) and Transforming Growth Factor-β (TGF-β), pro and anti-inflammation cytokines, respectively, significantly decreased and increased after blueberry supplementation, indicating a positive impact of blueberry ingestion in the reduction of risk of inflammation. The combined analysis of the urine metabolome and clinical markers represents a promising approach in monitoring the metabolic impact of blueberries in persons with metabolic syndrome.

(2) Sezer ED, Oktay LM, Karadadaş E, Memmedov H, Selvi Gunel N, Sözmen E. Assessing Anticancer Potential of Blueberry Flavonoids, Quercetin, Kaempferol, and Gentisic Acid, Through Oxidative Stress and Apoptosis Parameters on HCT-116 Cells. J Med Food. 2019 Nov;22(11):1118-1126. doi: 10.1089/jmf.2019.0098. 

Abstract. In recent years, natural products gained popularity with their anti-inflammatory and antioxidant effects mediated by chemical compounds within their composition. Study results offering them as palliative therapy options in cancer or as anticancer agents with high levels of cytotoxicity brought a new approach to combine cancer treatment protocols with these products. From a different perspective, edible types of these products are suggested in daily diets due to their potential cancer preventive effects. Our preliminary work was on blueberry extracts (Vaccinium myrtillus) as a main representative of these natural products, and the contents of the extracts were analyzed with liquid chromatography tandem mass spectrometry (LC MS/MS) to reveal the composition and distribution of polyphenolic compounds within. The most abundant polyphenols detected in V. myrtillus extracts were quercetin, kaempferol, and a phenolic acid, gentisic acid (GA). The compounds were further evaluated on treated HCT-116 cells for their potential anticancer effects by measuring total antioxidant status, total oxidant status, and 8-hydroxydeoxyguanosine levels for evaluation of oxidative stress and through protein array analysis and flow cytometric analysis for evaluation of apoptosis. In analysis of oxidative stress parameters, reduced total oxidant levels and reduced oxidative stress index levels were found in cells treated with the compounds in comparison with untreated cells. In apoptosis-related protein profiles, at least twofold reduction in various apoptotic proteins was observed after quercetin and kaempferol treatment, whereas a different profile was observed for GA. Overall, results of this study showed that quercetin and kaempferol have strong cytotoxic, antioxidant, and apoptotic effects, although GA is mostly effective as an antioxidant polyphenol on HCT-116 cells.

(3) Travica N, D'Cunha NM, Naumovski N, Kent K, Mellor DD, Firth J, Georgousopoulou EN, Dean OM, Loughman A, Jacka F, Marx W. The effect of blueberry interventions on cognitive performance and mood: A systematic review of randomized controlled trials. Brain Behav Immun. 2020 Mar;85:96-105. doi: 10.1016/j.bbi.2019.04.001. 

Abstract. Blueberries are rich in polyphenols that may be beneficial to cognitive performance and mood. The aim of this systematic review was to evaluate randomized controlled trials investigating the effects of blueberries and blueberry products on measures of cognition and mood. In total, eleven articles (that included 12 studies) were identified using freeze-dried blueberries (n = 9 studies), whole blueberries (n = 2) and blueberry concentrate (n = 1). These studies were conducted in children (n = 5), young adults (n = 1), and older people with either no known cognitive impairment (n = 4) or indicated cognitive impairment (n = 2). Eight studies reported blueberry consumption or supplementation at various doses and time lengths to improve measures of cognitive performance, particularly short- and long-term memory and spatial memory. For mood, one study reported significant between-group improvements in positive affect from blueberry products, whereas four studies reported no improvement. Low risk of bias were observed across all studies. Based on the current evidence, blueberries may improve some measures of cognitive performance. However, considerable differences in study design, dosages, and anthocyanin content hinder between-study comparison. The use of standardized blueberry interventions, consideration of placebo formulations, and consistently reported cognitive performance tools are recommended in future trials. PROSPERO registration no. CRD42018100888.

(4) Liu Y, Liu M, Chen Q, Liu GM, Cao MJ, Sun L, Lu Z, Guo C. Blueberry Polyphenols Ameliorate Visible Light and Lipid-Induced Injury of Retinal Pigment Epithelial Cells. J Agric Food Chem. 2018 Dec 5;66(48):12730-12740. doi: 10.1021/acs.jafc.8b05272. 

Abstract. Although dietary polyphenols are known to be beneficial to vision, the protective distinctions among different types of polyphenols are unclear. In this work, the visual benefits of various blueberry polyphenols were evaluated using an in vitro model of visible light-lipid-induced injury of retinal pigment epithelial cells. Results showed that, at 10.0 μg/mL, the phenolic acid-rich fraction was superior in inhibiting cell death (93.6% ± 2.8% of cell viability). Anthocyanin- and flavonoid-rich fractions shared similar advantages in preventing the expression of senescence-associated β-galactosidase (34.8% ± 11.1% and 32.2% ± 9.7% of aged cells, respectively) and overexpression of vascular endothelial growth factor (51.8 ± 3.5 and 54.1 ± 6.5 pg/mL, respectively). The flavonoid-rich fraction also showed high activity in ameliorating phagocytosis (70.3% ± 12.6%) and cellular oxidative stress. These results were further confirmed by using the corresponding polyphenol standards. Improved inhibitory effects of polyphenol mixture on cell death and senescence-associated β-galactosidase expression were also observed. Therefore, various polyphenols play diverse roles and exert synergistic effects in nourishing the retina.

(5) Barfoot KL, May G, Lamport DJ, Ricketts J, Riddell PM, Williams CM. The effects of acute wild blueberry supplementation on the cognition of 7-10-year-old schoolchildren. Eur J Nutr. 2019 Oct;58(7):2911-2920. doi: 10.1007/s00394-018-1843-6. 

Abstract. Purpose: Previous evidence suggests consumption of flavonoids, a sub-class of polyphenols, is associated with improved cognitive function across the lifespan. In particular, acute intervention of a flavonoid-rich wild blueberry (WBB) drink has been shown to boost executive function (EF), short-term memory and mood 2-6 h post-consumption in 7-10-year-old children. However, confirmation of the aspects of EF and memory susceptible to WBB ingestion is required, particularly during childhood, a critical period of neurological development. In addition, the child literature on berry flavonoid supplementation and cognition highlights the potential for such interventions to elicit positive benefits to real-world educational scenarios, such as reading, a complex ability which relies upon aspects of cognition already known to improve following WBB.....Conclusion: Consumption of WBB was found to significantly improve memory and attentional aspects of EF. This indicates that a flavonoid-rich blueberry product, equivalent to 240 g or 1½ cups of fresh blueberries can provide acute cognitive benefits in children. These findings support accumulating evidence that flavonoid-rich products are beneficial for healthy brain function, particularly during critical developmental periods. However, the lack of findings relating to reading ability suggested acute WBB may not be sufficient to elicit benefits to reading. Chronic supplementation and other more sensitive reading measures should be considered for examining the effects of WBB on such a complex skill in the future.