Bilberry is a blueberry-like dark purple/blue-black berry (also known as European blueberry, bilberry, bilberry, bilberry, bilberry, bilberry) produced by bilberry, which is higher in anthocyanins than other types of berries, such as strawberries, elderberries, tart cherries and cranberries, and is a key bioactive substance.
Bilberry is sold primarily as fresh, frozen, and dried whole berries and is also sold as preserves, jams, juices, or food supplements.
In empirical medicine, have the benefits of bilberry been proven? Are there any side effects of Bilberry? See text analysis for details.
What is bilberry?
Bilberry, a fruit of a low shrub from Central and Northern Europe (about 5 to 9 mm in diameter, blue-black in color, characterized by a variety of seeds), also grows in parts of North America and Asia, and is a plant in the family Ericaceous/Vaccinium along with blueberries and cranberries
The fruit of bilberry is rich in a variety of plant polyphenols (including anthocyanins, flavonols, quercetin, catechins, ellagins, tannins, phenolic acids, etc.), among which anthocyanins are the most abundant, and are also the main targets in research, with eyesight protection, antioxidant, anti-inflammatory and other effects.
In traditional medicine, bilberry has potential value in the treatment or prevention of varicose veins, venous insufficiency, diarrhea, gastrointestinal discomfort, diabetes, irritability, ulcerative colitis, glaucoma, eye fatigue, myopia, night vision, weight loss, and dysmenorrhea
What is the difference between bilberry and blueberry?
Bilberry is also sometimes mistaken for a blueberry because the two have a similar appearance, but true blueberries are native to North America.
Although they are closely related and belong to the same plant, bilberry and blueberry are different, how can you tell the difference?
In terms of appearance, the easiest way to distinguish is that bilberry is smaller and darker than blueberry, the flesh color of bilberry is blue, while the flesh color of blueberry is green, with an unfolded corolla at the end.
In addition, bilberry has a higher content of anthocyanins, between 300 and 700 mg per <> grams of fresh fruit, which also varies according to the variety, growing conditions and maturity.
Anthocyanins are water-soluble polyphenolic flavonoids that are the main source of the colorful colors of plants.
Blueberries, on the other hand, contain higher levels of other phenolic compounds such as chlorogenic acid, coumaric acid, rutin, resveratrol, and epicatechins.
What are the proven benefits of bilberry?
Bilberry has rich antioxidant activity
Studies have shown that bilberry is rich in anthocyanins (about 300 to 700 mg of anthocyanins per 100 grams) and is a powerful flavonoid antioxidant. Note 1
Flavonoids are the largest class of naturally occurring phenolic compounds, present in different parts of plants in the form of free states and glycosides, they have antibacterial, inhibition mitochondrial adhesion, antiulceration, antiarthritis, antiangiogenesis, anticancer, protein kinase inhibition and other biological activities.
In addition to the benefits for human health, phenolic compounds in plant tissues are actively involved in plant protection, resistance to bacterial and fungal infections, ultraviolet radiation, physical damage, etc.
Bilberry is good for myopia
Myopia is the most common eye disease in the world, with about 22.9% of the world’s population, or 14.06 billion people, suffering from myopia, and another 2.7% (1 million people) suffering from high myopia.
Many East Asian countries are particularly affected, with myopia rates in schools exceeding 90 per cent in some areas. It is characterized by prolonged axial length and can cause a variety of specific complications, including cataract formation, retinal detachment, macular traction lesions, vaulting macular, choroidal/scleral thinning, myopic choroidal neovascularization, and glaucoma.
One randomized controlled trial (2-year, 64 children with high myopia) was divided into two groups, one using Difrarel E capsules (containing bilberry extract and vitamin E) and the other not taking any formula. Note 2
The results showed that the refractive light and axial length of the right eye were significantly improved in the group using bilberry extract, and the difference between the two groups was still significant after discontinuation.
*Conclusion: Bilberry extract may have a positive effect on delaying myopia progression, but limited by the small sample size, more large trials are still needed to support it
Bilberry is good for eyestrain
The use of video display terminals (e.g., computers, mobile phones) has led to major changes in the way millions of people work in the workplace, bringing convenience, but on the other hand, it has also led to an increase in eye diseases, which are often classified as computer vision syndrome
Computer vision syndrome is mainly manifested as itchy eyes, redness, burning, tears, headache, double vision, eye fatigue, blurred vision, in addition to reducing the use time of electronic screens, ergonomic furniture use, reducing glare sources, adjusting temperature, humidity, monitor position, work tasks, environmental factors are necessary to avoid computer vision syndrome
A prospective, randomized, double-blind, placebo-controlled study (8 weeks, 281 office workers) showed that oral bilberry extract (480 mg per day) improved visual fatigue (measured by visual flash fusion threshold) due to acute video display terminal load, as well as other subjective symptoms such as eye pain, heaviness, discomfort, and foreign body sensation. Note 3
*Conclusion: Oral bilberry extract may have a positive effect on improving visual fatigue caused by electronic screens, but limited by the small sample size, more large trials are needed to support it
Bilberry is good for dry eye
Dry eye disease is a tear film disorder caused by lack or excessive evaporation of tear fluid, which causes damage to the ocular surface and has a significant negative impact on the physical and mental health of patients because patients feel discomfort, pain, and vision changes that prevent them from performing basic activities of daily living, such as reading, watching TV, driving, and working.
The global prevalence of dry eye varies from 20% to 50%, and the prevalence in younger populations is often associated with the use of 3C devices and myopia treatment, including contact lenses and laser myopia surgery, in addition to autoimmune diseases, hormonal changes and systemic drug therapy can also cause dry eye.
A randomized, double-blind, placebo-controlled (4-week study of 22 healthy subjects with dry eye symptoms) showed that oral standardized bilberry extract increased tear production (as measured by Schirmer’s test), with more severe dry eye symptoms. Note 4
*Conclusion: Oral bilberry extract may be helpful in improving dry eye syndrome, but due to small sample sizes, more large trials are needed to support this
Bilberry is good for type 2 diabetes
Diabetes mellitus is a metabolic disorder characterized by high blood sugar, abnormal lipid and protein metabolism, and long-term complications of the retina, kidneys, and nervous system.
The basis for treating people with diabetes is usually improved dietary intake and exercise as the two main determinants. In addition, lack of sleep can worsen insulin resistance, high blood pressure, high blood sugar, and dyslipidemia.
A randomized, double-blind controlled trial (in eight participants with type 2 diabetes controlled only by diet and lifestyle) showed that oral bilberry capsules helped reduce the incremental area under the glucose and insulin curves after oral glucose tolerance testing compared to placebo. Note 5
*Conclusion: Oral bilberry extract may have a positive effect on reducing postprandial blood glucose and insulin, but limited by small sample sizes, more large randomized controlled trials are needed
Bilberry improves night vision
Under normal visual conditions, we can enjoy the benefits of a wide field of view, mainly for navigation and positioning, while the high-resolution capabilities of the fovea allow us to discern details.
According to German road traffic statistics, although the traffic volume at night accounts for only 20% of the day, but 40% of traffic accidents occur, so having good night vision is very important for drivers, military personnel and even the elderly.
In a systematic review (12 placebo-controlled trials), it was noted that there has been no rigorous demonstration of the efficacy of mulberry to improve or enhance night vision in people with normal or above-average vision. Note 6
In addition, for night vision disorders caused by pathological eye diseases, there is currently a complete lack of rigorous research to support them.
*Conclusion: To date, there is no clear evidence that bilberry has the effect of improving night vision
Bilberry regulates inflammation factor
Inflammation is the body’s immune response in the face of infection or foreign body invasion (often in the form of redness, swelling, heat and pain), in fact, inflammation itself is beneficial (is the process of immune cells to clear and repair), if the loss of inflammation, it means that the body loses immunity, just like AIDS patients, any little infection will be fatal.
In a small human randomized controlled trial, bilberry juice was found to regulate a variety of markers related to inflammation, such as C-Reactive Protein, cytokines IL-6, IL-15, tumor necrosis factor (TNF-alpha), and inhibition of these factors can reduce NF-kappaB activation and regulate inflammation (NF-kappaB is also known as the inflammatory switch in cells. is a protein complex). Note 7
Bilberry prevents macular degeneration and cataract (animal research)
In recent years, it has been clinically found that eye diseases (such as macular degeneration and cataracts), which used to be mainly elderly and highly myopic groups, have appeared in young and middle-aged people.
The common characteristic of this group of patients is the daily use of 3 C products, due to excessive reception of blue light from the screen, resulting in oxidative damage to the lens and macula, increasing the chance of degeneration and lesions, so learning how to prevent it has become an important issue.
In an animal-controlled experiment, mice were divided into two groups (barberry or vitamin E), and after 3 months, bilberry extract was found to have antioxidant effects and prevent macular degeneration and cataract (70% of the control group taking vitamin E had macular degeneration and cataracts). Note 8
*Conclusion: Bilberry may be helpful in preventing degenerative ocular diseases, but further validation is needed in human studies
Are there any side effects of bilberry?
As a regular food, the dried or ripe fruit of bilberry is safe for most people.
Artificial extraction of bilberry supplements is also considered safe when used appropriately, but possible side effects or adverse reactions have been reported: nausea, mild heartburn, exhaust, gastrointestinal upset, rash and tiredness.
- Pregnant women, breastfeeding women, children or people with poor liver and kidney function should not use related health care preparations (due to unknown safety)
- Patients with poor coagulation function or taking anticoagulants should not use it, because anthocyanosides, the main component of bilberry, has anticoagulant effects. The names of related drugs are: Aspirin, clopidogrel , Diclofenac, ibuprofen, naproxen, dalteparin (dalteparin sodium), enoxaparin, heparin, warfarin
- Do not use diabetic patients or those taking related hypoglycemic drugs, because bilberry may have a hypoglycemic effect, the related drug names are: glimepiride, glyburide (glibenclamide), insulin, pioglitazone, rosiglitazone, chlorpropamide, glipizide, tolbutamide
- Discontinue use two weeks before surgery, it may affect blood sugar control during and after surgery.
- Bilberry leaves are not recommended to be consumed because they contain a lot of tannins, and excessive amounts may cause weight loss, muscle spasms, and may be fatal in serious cases.
- Avoid the simultaneous use of health ingredients or herbs that may affect blood sugar, such as: Devil’s claw, fenugreek, garlic, guar gum, horse chestnut, Panax ginseng, psyllium, Siberian ginseng
- Avoid the simultaneous use of health ingredients or herbs that may affect blood clotting function, such as: angelica, capsicum, clove, danshen, ginger, ginkgo, poplar, safflower alfalfa (red clover), turmeric, willow.
- Avoid using chromium-containing health ingredients or herbs such as brewer’s yeast, cascara and horsetail.
- Food allergies may occur, although extremely rare, but can still occur, and two cases have been reported with symptoms such as itching, shortness of breath, anaphylactic shock, due to the possible presence of sulfites, vasoactive amines, benzoates and salicylates in berries (blueberries or bilberry), which may trigger inflammation in sensitive or intolerant people.
How is bilberry used? What is the dose?
Limited studies and large differences in dosage make it difficult to decide on the optimal dose.
Only the most common doses in clinical trials (typically used for about 8 to 12 weeks) are listed below:
However, it is still recommended to consult a specialist regarding your condition before using herbal supplements to ensure safe use
Chronic venous insufficiency: 173 mg of anthocyanins per day
Cholesterol lowering: 65 to 300 grams of berries or 320 mg of extract per day
Weight loss: 100 grams of berries per day
Eye diseases: 59 to 180 mg of anthocyanins per day
Diabetes: 50 to 300 grams of berries per meal