How Bilberry Can Help The Macula and Macular Health

How Bilberry Can Help The Macula and Macular Health

 

Bilberries are small, deep reddish-blue berries that can be found growing on shrubs in the northern forests of Europe, the Rocky Mountains of North America, and western Asia. Scientifically, a bilberry is also known as Vaccinium myrtillus and are of the same genus (family of plants) as the blueberry, buckberry, huckleberry, farkleberry, cranberry, whortleberry and crowberry.

The bilberry fruit and its extract are powerhouses of good nutrition. The medicinal legacy of bilberry fruit, bilberry juice and bilberry leaves has been documented for more than 1000 years. Bilberry has been used as an herbal medicine to treat cough, sore throat, tuberculosis and diarrhea. More recently, in the Second World War, the fighter pilots of the Royal Air Force reported that their night vision was enhanced after eating bilberry jam the night before a mission. Clinical studies following World War II supported these claims made by the British soldiers. [2, 15]

Currently, bilberry fruit is used in jams and as a baking ingredient, but the concentrated extract is used in supplements to help manage circulation issues, disorders of the retina, glaucoma, and cataracts.  

The medicinal legacy of bilberry fruit, juice and leaves has been documented for more than 1000 years, used as an herbal medicine to treat cough, sore throat, tuberculosis and diarrhea.

The pharmacologically active ingredients of the bilberry are a group of compounds called anthocyanins, which have powerful antioxidant and anti-inflammatory effects. Bilberry has 15 different forms of anthocyanins, derived from anthocyan, the pigment that determines the red, blue and violet colors of flowers and fruits. [1, 10] The fresh fruit contains an anthocyanidin concentration of 0.1 to 0.25 percent. A concentrated bilberry extract however, yields 25% anthocyanidin content. 

Bilberry also contains vitamin A, vitamin C, catechol tannins, and hydroquinone, some of which may contribute to the overall benefits of whole bilberry.

 

What are the health benefits of bilberry?

Bilberry has been scientifically proven to have the following benefits:

• Antioxidant activity – preventing oxidation that produces free radicals that can lead to cell damage.  [11] 
• Anti-inflammatory
• Promotion of collagen biosynthesis [9]
• Inhibition of platelet aggregation (formation of blood clots) [9]
• Improvement in vascular tone, blood flow, and vasculoprotective activity - improved circulation throughout the blood vessels in the body, delivering oxygen and nutrient-rich blood to our cells [3]
• Improves visual function [12]
• Alleviates visual fatigue [13, 6]
• Protective effects against light-induced retinal damage [11, 7]

 

How does bilberry affect and protect the retina and macula?

Our retinas are highly susceptible to photochemical damage from continuous exposure to light and oxygen. Research has shown that anthocyanin-rich bilberry extract may have to ability to inhibit multiple biological pathways in the retina to protect visual function. [8] 

Over time, the macula (the backmost part of the retina responsible for central vision), can be damaged by oxidative stress or ultraviolet light. This light exposure is known to be a contributing factor to eye diseases such as age-related macular degeneration and can also contribute to the formation of cataracts. In plants, anthocyanins have been shown to protect cells from photo-damage by absorbing blue-green light, thereby protecting the cells from high light stress. 

Excessive oxidative stress destroys tissue in ocular disease, including age-related macular degeneration. Anthocyanin-rich bilberry extract also acts as a powerful antioxidant, helping to protect the plant from radicals formed by UV light and during metabolic processes. These antioxidant properties are conserved even after consumption by another organism (like humans), which is another reason why fruits and vegetables with red or blue skins and tissues are a nutritious food source. The increased levels of antioxidants  can help suppress chemical reactions that cause inflammation and result in retinal cell death, thereby having a tissue-protecting effect. [14]

Photoreceptors are specialized cells within the layers of the retina that convert light into the signals that are sent via the optic nerve to the brain, creating vision. In basic science studies (animal models) treatment with bilberry extract preserved visual function, including photoreceptor cell function. This occurred because the anthocyanin-rich bilberry extract reduced production of specific proteins and mechanisms inside the cells that accompany inflammation of the retina, protecting the photoreceptor cells from impairment.  [8]

Several studies have shown that people with different types of circulation problems who took bilberry extract daily, experienced improvements in circulation (blood flow) and vascular function.

Several studies beginning in the 1980s, have shown that people with different types of circulation problems who took bilberry extract daily, experienced improvement in blood flow. This beneficial effect on circulation (blood flow) also included the vessels of the retina. In studies of diabetic rats treated with bilberry extract, they found that there was less leakage of blood vessels and decreased makers for diabetic retinopathy, including expression of retinal vascular endothelial growth factor (VEGF). These findings were considered to have very important implications for the potential prevention or delayed onset of early diabetic retinopathy. [5] A small study (of 14 people) that had experienced damage to retinal blood vessels from diabetic changes or high blood pressure, showed that after 1 month of bilberry extract supplementation, the health of their retinal blood vessels had improved. 

All of these important qualities allow bilberry to help protect the cells that make up the retina and protect retinal function. This is key to preventing and inhibiting the progression of retinal disorders like age-related macular degeneration, and retinitis pigmentosa. 

 

Where can you find bilberries or bilberry extract?

Even though bilberries are grown in Europe, Western Asia and high in the forests of the North American Rocky Mountains, getting fresh, or even frozen, bilberries can be difficult. Determining the amount of bilberry extract you are actually getting using fresh or juiced bilberries can be difficult, so taking a high quality supplement can deliver the desired amount.  

As with any health supplement, it is important to speak to your doctor, especially if you are taking other medications for things like diabetes or circulation and clotting disorders.  

Is taking a bilberry supplement safe?

Large research studies have been conducted, establishing and confirming the safety of taking bilberry. One study followed 2,295 people who had been prescribed a 36% anthocyanoside standardized bilberry fruit extract, and the researchers reported no adverse effects for prolonged use of the extract. [4] The German Commission E monograph on bilberry fruits lists no known contraindication, interactions with other drugs, or side effects. The bilberry fruit has a long history of food use, a 1000 year history as a herbal medicine, and more than 50 year history of dietary supplementation for many different clinical symptoms with no reported safety concerns.

 

Can bilberry extract help with other eye disorders?

Cataracts - In 1989 Dr. Bravetti, an Italian researcher, reported the use of bilberry extract and vitamin E for four months in 50 patients with cataracts. They found that in 96%, cataracts progressed more slowly.  

Glaucoma - A very small study of only eight patients given a single dose of bilberry extract, showed results that may demonstrate some benefits of bilberry extract for people with glaucoma. These patients showed some improvement in electroretinography testing, which measures the electrical response from the eye's light-sensitive cells, rods and cones. Similarly, a study of 132 glaucoma patients in Korea showed improved vision. Researchers have speculated that bilberry extract’s collagen stabilizing and biosynthesis abilities may provide some benefits to the structures in the eye responsible for aqueous outflow that can be impaired in people with glaucoma.  

Eye Strain & Fatigue - A 2014 study by Kono reported that in 48 people who experienced eye strain on a daily basis, who took a supplement containing astaxanthin, lutein, bilberry extract, black soybean hull extract (as cyanidin-3-glucoside in both extracts), and DHA for four consecutive weeks, had improved eye function and fewer symptoms of eye strain.  

 

References:

[1] Baj A, Bombardelli E, Gabetta B, Martinelli EM. Qualitative and quantitative evaluation of vaccinium myrtillus anthocyanins by high-resolution gas chromatography and high-performance liquid chromatography. J Chromatogr A. 1983;279:365–72. 

[2] Cluzel C, Bastide P, Wegman R, et al. Enzymatic activities of retina and anthocyanoside extracts of vaccinium myrtillus (lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, alpha-glycerophosphate dehydrogenase, 5-nucleotidase, phosphoglucose isomerase). Biochem Pharmacol 1970;19(7):2295-302. https://www.ncbi.nlm.nih.gov/pubmed/4329039

[3] Colantunoni A, Bertuglia S, Magistretti MJ, Donato L. Effects of Vaccinium myrtillus anthocyanosides on arterial vasomotion. Arzneimittelforschung. 19 91;41:905–9. 

[4] Eandi M. Post Marketing Investigation on Tegens? Preparation with Respect to Side Effects. Unpublished Results. Cited by: Morazzoni P, Bombardelli E. Vaccinium Myrtillus.  Fitoterapia. 1996;67:3–29. 

[5] Kim J, Kim CS, Lee YM, Sohn E, Jo K, Kim JS. Vaccinium myrtillus extract prevents or delays the onset of diabetes--induced blood-retinal barrier breakdown. Int J Food Sci Nutr. 2015 Mar;66(2):236-42. https://www.ncbi.nlm.nih.gov/pubmed/25582181

[6] Kono K, Shimizu Y et al. Effect of Multiple Dietary Supplement Containing Lutein, Astaxanthin, Cyanidin-3-Glucoside, and DHA on Accommodative Ability. Curr Med Chem. 2014 Aug; 14(2): 114–125. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4997915/

[7] Matsunaga N, Tsuruma K, Shimazawa M, Yokota S, Hara H. Inhibitory actions of bilberry anthocyanidins on angiogenesis. Phytother Res. 2010;24(Suppl 1):S42–7. https://www.ncbi.nlm.nih.gov/pubmed/19496063

[8] Miyake S, Takahashi N, Sasaki M, Kobayashi S, Tsubota K, Ozawa Y. Vision preservation during retinal inflammation by anthocyanin-rich bilberry extract: cellular and molecular mechanism. Lab Invest. 2012;92:102–9. https://www.ncbi.nlm.nih.gov/pubmed/21894150

[9] Morazzoni P, Megistretti MJ. Activity of myrtocyanR, an anthocyanoside complex from Vaccinium myrtillus (VMA), on platelet aggregation and adhesiveness. Fitoterapia. 1990;61:13–21. https://www.cabdirect.org/cabdirect/abstract/19900360312

[10] Nakajima J, Tanaka I, Seo S, Yamazaki M, Saito K. LC/PDA/ESI-MS Profiling and Radical Scavenging Activity of Anthocyanins in Various Berries. J Biomed Biotechnol. 2004;2004:241–7. https://www.ncbi.nlm.nih.gov/pubmed/15577184

[11] Ogawa K, Tsuruma K, Tanaka J, Kakino M, Kobayashi S, Shimazawa M, Hara H. The protective effects of bilberry and lingonberry extracts against UV light-induced retinal photoreceptor cell damage in vitro. J Agric Food Chem. 2013;61:10345–53. https://www.ncbi.nlm.nih.gov/pubmed/24083563

[12] Osada H, Okamoto T, Kawashima H, Toda E, Miyake S, Nagai N, Kobayashi S, Tsubota K, Ozawa Y. Neuroprotective effect of bilberry extract in a murine model of photo-stressed retina. PLoS One. 2017;12:e0178627. https://www.ncbi.nlm.nih.gov/pubmed/28570634

[13] Ozawa Y, Kawashima M, Inoue S, Inagaki E, Suzuki A, Ooe E, Kobayashi S, Tsubota K. Bilberry extract supplementation for preventing eye fatigue in video display terminal workers. J Nutr Health Aging. 2015;19:548–54. https://www.ncbi.nlm.nih.gov/pubmed/25923485

[14] Wang Y, Zhao L, Lu F, Yang X, Deng Q, Ji B, Huang F.  Retinoprotective Effects of Bilberry Anthocyanins via Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Mechanisms in a Visible Light-Induced Retinal Degeneration Model in Pigmented Rabbits. Molecules. 2015 Dec 14;20(12):22395-410. https://www.ncbi.nlm.nih.gov/pubmed/26694327

[15] Wegmann R, Maeda K, Tronche P, et al. Effects of anthocyanosides on photoreceptors. cytoenzymatic aspects. Ann Histochim 1969;14(3):237-56.