What are Blueberries ?
- What are Blueberries ?
- Health Benefits Of Blueberries
- Side Effects Of Blueberries
Bilberry (Vaccinium myrtillus L.) belongs to a genus Vaccinuim corymbosum.
Its blue/black colour originates from polyphenolic compounds named anthocyanins (300-700 mg/100 g). Their name comes from the Greek word ‘’anthos’’ that means flower and ‘’kyanose’’ meaning blue. (1)
The blueberry plant is a low-growing plant that originates from northern Europe, North America and Asia. Its common names are European blueberry, whortleberry, huckleberry and blueberry.
Phytochemicals or photonutrients are naturally-occurring non-nutritive constituents of fruits and vegetables. They represent bioactive substances and have positive impact on human health.
Blueberries are rich source of vitamin C and K, manganese and dietary fibers. Blueberries are among the fruits highest in antioxidant power, mostly phytochemicals. They are aswell rich in anthocyanins, catechins, quertecin, kaempferol and other types of flavonoids. (2)
The main metabolic products of anthocyanins are found in urine. They are glucuronated methylated.
Anthocyanins are powerful antioxidants and are involved in cell signaling pathways, gene regulation, DNA repair and cell adhesion. They are effective as anticancer and antimicrobial substances.
Blueberries are most known by its positive effect on eye vision, decreasing glucose levels, antiinflammatory,cholesterol lowering properties and antioxidative effect.
Health Benefits Of Blueberries
Blueberries are of great value in the treatment and prevention of inflammation, dyslipidemia, hyperglycemia, high oxidative stress, cardiovascular disorders, cancer, diabetes and certain neurological disorders.
Blueberries are rich in phenolic compounds such as carotenoids (lutein, zeaxanthin), flavonoids (quercetin, catechins), tannins, ellagitannins and phenolic acid. They are abundant in vitamin C,E, selenium, zinc and phosphorus. Such substances have strong antioxidative properties and are iron-helators.
Blueberries are high in antioxidative substances, such as anthocyanine, that may delay aging process. They are as well rich in vitamin C that reduces the wrinkles and stimulates the synthesis of collagen.
Polyphenols in blueberries may prevent osteoporosis. They are able to stimulate bone growth and delay the onset of osteoporosis.
It has been shown that polyphenols are able to stimulate bone growth due to enhanced osteoblast activation.
Blueberries are abundant in antioxidants that act neuroprotectivly.In individuals that consumed high amounts of blueberries the memory improvement and use of words was better due to anthocyanines. (3)
Blueberries are,as kale, the potent stimulator of human immune system due to high levels of antioxidant substances, vitamins, carotenoids, flavonoids and phenolic compounds.
The anthocyanin, the selenium, vitamin A, vitamin B complex, vitamin C and all other vitamins in blueberries are neuroprotective. They are able to delay and repair the damage of the neuronal cells. (4)
Anthocyanins are able to protect DNA against oxidative stress in case of an exposure to UV radiation and hydrogen peroxide.
They are concentrated mostly in the skin of the blueberries.
They are potent antioxidants and are able to stabilize DNA, change adipocyte gene expression, improve insulin metabolism. Anthocyanins have as well antiinflammatory and antibacterial effects.
Blueberries are potent antioxidant fruit due to high level of phenolics and other vitamins such as vitamin, C, E and flavonoids.(5)
Blueberries are abundant in pterotsilbene, ellagic acid and anthocyanine that may prevent the onset of colorectal and liver cancer. (6)
Pterostilbene is a potent antioxidant (trans-3,5-dimethoxy-4-hydroxystilbene)(7) found in blueberrie. It is as well neuroprotective substance, delays aging and regulates blood glucose levels.
Bluberries, similar to kale, are rich in antioxidants, mainly carotenoids and flavonoids that may prevent certain types of cancer.(8)
It could show an effect on gastrointestinal microorganism flora. Blueberries prevent constipation and enhance digestion.
Blueberries are rich in fiber and may control the body weight.
The high intake of blueberries, as kale, leads to the modification of the concentration of certain bacterial species and probiotic effects in the gastrointestinal tract.
The vitamins, sodium, cooper and fructose in blueberries enhance digestion due to its stimulation of gastrointestinal secretions.
9.Urinary Tract Infection
This condition arises mostly from the presence of Escherichia coli bacteria. It leads to the inflammation of the urogenital mucosa and other complications. Blueberries are rich in antiinflammatory and antioxidative substances.
The rich antioxidative potential (carotenoids, zeaxanthin, quercetin) of blueberries is able to prevent or delay the onset of macular degeneration.
They are as well useful in hypermetrops, myops, cataracts and eye structure infections.
The phenolic compounds in blueberries such as chlorogenic acid, quercetin, ellagic acid and quercetin-3-galactoside possess antimicrobial activity. (9)
Blueberries are effective in the improvement of night vision because they improve vascular permeability and capillary fragility. Such effect is mostly due to antioxidant activities of anthocyanin.(10)
13.Genoprotective And Anticancer Effects
Cancer is a disease due to a mutated genes. predominantly mutations in key genes controlling cell division and growth. The main process is an oxidation-induced damage. The presence of chronic inflammation leads to increased level of oxidative radicals as well as an increased risk for the cancer growth.(11)
There is direct link between anthocyanins with DNA strands with formation of a DNA complex. Thus, anthocyanins may regulate gene expression while protecting DNA in case of oxidative impairment. Ellagic acid is a phenolic substance with anticancer attributes and even it may reverse the presence of cancer nodus. It is able to exhibit antiviral and antibacterial functions. (12)
Side Effects Of Blueberries
- Blueberries may cause adverse effects in gastrointestinal tract due to high level of salycilate. Salycilate may lead to gastrointestinal irritation. In children, it may cause even convulsions and coma.
- Tannins in blueberries may cause liver and kidney disfunctions.
- Rolf Nestby. The European Blueberry (Vaccinium myrtilis L) and the potential for cultivation. The European Journal for plant cultivation.
- Wu-yang Huang et al. Survey of antioxidant capacity and phenolic composition of blueberry, blackberry, and strawberry in Nanjing. J Zhejiang Univ Sci B. 2012 Feb; 13(2): 94–102.
- Robert Krikorian et al.Blueberry Supplementation Improves Memory in Older Adults. J Agric Food Chem. 2010 Apr 14; 58(7): 3996–4000.
- Andres-Lacueva C et al. Anthocyanins in aged blueberry-fed rats are found centrally and may enhance memory.
- Kähkönen MP, Hopia AI, Heinonen M. Berry phenolics and their antioxidant activity.J Agric Food Chem. 2001 Aug;49(8):4076-82.
- Johnson SA, Arjmandi BH.Evidence for anti-cancer properties of blueberries: a mini-review.Anticancer Agents Med Chem. 2013 Oct;13(8):1142-8.
- Denise McCormack, David McFadden. A Review of Pterostilbene Antioxidant Activity and Disease Modification. Oxid Med Cell Longev. 2013; 2013: 575482.
- Olsson ME1, Gustavsson KE, Andersson S, Nilsson A, Duan RD.Inhibition of cancer cell proliferation in vitro by fruit and berry extracts and correlations with antioxidant levels.
- Olsson M et al. Inhibition of cancer cell proliferation in vitro by fruit and berry extracts and correlations with antioxidant levels. J Agric Food Chem. 2004; 52: 7264-71. 2. Yi W, Fischer J, Krewer G, Akoh C.
- Phenolic compounds from blueberries can inhibit colon cancer cell proliferation and induce apoptosis. J Agric Food Chem. 2005; 53: 7320-29 3. Seeram N et al.
- Blackberry, black raspberry, blueberry, cranberry, red raspberry and strawberry extracts inhibit growth and stimulate apoptosis of human cancer cells in vitro. J Agric Food Chem. 2006; 54: 9329-39.
- McAnulty SR et al. Effect of daily fruit ingestion on angiotensin converting enzyme activity, blood pressure, and oxidative stress in chronic smokers. Free Radic Res. 2005; 39(11): 1241-8.
- Lau FC et al. Beneficial effects of fruit polyphenols on brain aging.
- Ramierz MR et al. Effect of lyophilized Vaccinium berries on memory, anxiety and locomotion in adult rats. Pharmacol Res. 2005; 52 (6): 457-62.